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{{Short description|Area of scientific research}}
{{Primary sources|date=July 2014}}
{{Sex differences}} {{Sex differences}}
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Sex differences in ] have long been a topic of debate among researchers and scholars. It is now recognized that there are no significant sex differences in average IQ,<ref name="Hunt">{{cite book|last1=Hunt|first1= Earl B.|author-link1=Earl B. Hunt|title =Human Intelligence|isbn =978-1139495110|publisher=]|year=2010|page=389|url=https://books.google.com/books?id=DwO4TtKAiCoC&pg=PA389}}</ref><ref name=":7">{{Cite book |last=Halpern |first=Diane F. |chapter-url=https://books.google.com/books?id=guzbKF8vTVcC&pg=PA964 |title=Encyclopedia of Women and Gender |publisher=Elsevier Science |year=2001 |isbn=0080548490 |editor-last=Worell |editor-first=Judith |pages=964 |chapter=Sex Difference Research – Cognitive Abilities |author-link=Diane F. Halpern}}</ref> though particular subtypes of intelligence vary somewhat between sexes.<ref name="Hunt 2">{{cite book |last1=Hunt |first1=Earl B. |url=https://books.google.com/books?id=DwO4TtKAiCoC&pg=PA378 |title=Human Intelligence |publisher=] |year=2010 |isbn=978-1139495110 |pages=378–379 |author-link1=Earl B. Hunt}}</ref><ref name="Mackintosh">{{cite book|url=https://books.google.com/books?id=BcKcAQAAQBAJ&pg=PA362|title=IQ and Human Intelligence|vauthors=Mackintosh N|publisher=]|year=2011|isbn=978-0199585595|pages=362–363}}</ref>


While some test batteries show slightly greater intelligence in males, others show slightly greater intelligence in females.<ref name="Hunt 2" /><ref name="Mackintosh"/> In particular, studies have shown female subjects performing better on tasks related to ],<ref name="Hunt"/> and males performing better on tasks related to rotation of objects in space, often categorized as ].<ref name="Terry">{{cite book|url=https://books.google.com/books?id=4s5WCgAAQBAJ&pg=PA356|title=Learning and Memory: Basic Principles, Processes, and Procedures, Fourth Edition|vauthors=Terry WS|publisher=]|year=2015|isbn=978-1317350873|page=356}}</ref>
Differences in intelligence have long been a topic of debate among researchers and scholars. With the advent of the concept of ''g'' or ] some form of empiricism was allowed, but results are often inconsistent with studies showing either no differences or advantages for both sexes, with many showing a slight advantage for males.<ref name="Lynn2004"/><ref name="Lynn2005"/><ref name="ReferenceB">{{cite journal |doi=10.1016/0191-8869(94)90030-2 |title=Sex differences in intelligence and brain size: A paradox resolved |year=1994 |last1=Lynn |first1=Richard |journal=Personality and Individual Differences |volume=17 |issue=2 |pages=257–71}}</ref><ref name="Intelligence: A gender bender">{{cite journal |doi=10.1038/438031a |title=Intelligence: A gender bender |year=2005 |last1=Blinkhorn |first1=Steve |journal=Nature |volume=438 |issue=7064 |pages=31–2 |pmid=16267535|bibcode = 2005Natur.438...31B }}</ref><ref name="ReferenceC">{{cite journal |doi=10.1038/nature04966 |title=Intelligence: Is there a sex difference in IQ scores? |year=2006 |last1=Irwing |first1=Paul |last2=Lynn |first2=Richard |journal=Nature |volume=442 |issue=7098 |pages=E1; discussion E1–2 |pmid=16823409|bibcode = 2006Natur.442E...1I }}</ref><ref name="Jackson and Rushton"/><ref name="Nyborg2005"/> One study did find some advantage for women in later life,<ref>{{cite journal |doi=10.1016/j.intell.2007.11.001 |title=Sex differences in latent cognitive abilities ages 6 to 59: Evidence from the Woodcock–Johnson III tests of cognitive abilities |year=2008 |last1=Keith |first1=Timothy Z. |last2=Reynolds |first2=Matthew R. |last3=Patel |first3=Puja G. |last4=Ridley |first4=Kristen P. |journal=Intelligence |volume=36 |issue=6 |pages=502–25}}</ref> while another found that male advantages on some cognitive tests are minimized when controlling for socioeconomic factors.<ref name="jorm"/> The differences in average ] between men and women are small in magnitude and inconsistent in direction.<ref name="lrainc.com"/><ref name="Baumeister1"/><ref name="Baumeister2"/><ref name="Hedges and Nowell"/><ref name="Colom2002"/> Some studies have concluded that there is larger variability in male scores compared to female scores, which results in more males than females in the top and bottom of the IQ distribution.<ref name="Deary"/><ref name="WaiCacchio2010"/> This remains a controversial claim.<ref>{{cite journal |author=Spelke, E. |year=2005 |title=Sex differences in intrinsic aptitude for mathematics and science?: A critical review |journal=American Psychologist |pages=950–958 |pmid=16366817 |url=http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.69.5544&rep=rep1&type=pdf}}</ref>


Some research indicates that male advantages on some ] are minimized when controlling for socioeconomic factors.<ref name="Mackintosh"/> It has also been hypothesized that there is slightly ] in male scores in certain areas compared to female scores, leading to males' being over-represented at the top and bottom extremes of the distribution, though the evidence for this hypothesis is inconclusive.<ref name=":9" />
There are however differences in the capacity of males and females in performing certain tasks, such as rotation of object in space, often categorized as ''spatial ability''.


==IQ research ==
== Historical perspectives ==
{{see also|Intelligence quotient}}


===Background===
Prior to the 20th century, it was a commonly held view that men were intellectually superior to women.<ref>{{cite book|last1=Lips|first1=Hilary M.|title=Sex & Gender: An Introduction|date=1997|publisher=Mayfield|location=Mountain View, Calif.|isbn=1559346302|page=40|edition=3rd}}</ref><ref>{{cite book|last1=Denmark|first1=Florence L.|last2=Paludi|first2=Michele A.|title=Psychology of Women: A Handbook of Issues and Theories|date=2008|publisher=Praeger|location=Westport, Conn.|isbn=0275991628|pages=7–11|edition=2nd}}</ref> ] argued (1801) that women were naturally suited to domestic work and not spheres suited to men such as politics, science, or business. He argued that this was because women did not possess the same level of rational thinking that men did and had naturally superior abilities in skills related to family support.<ref>Thomas Gisborne, An enquiry into the duties of the female sex, Printed by A. Strahan for T. Cadell jun. and W. Davies, 1801{{page needed|date=June 2013}}</ref>
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There is no statistically significant difference between the average ] of men and women.<ref name="Hunt" /><ref name="Sternberg" /><ref name="Mackintosh"/><ref name="Child">{{cite book|vauthors=Child D|title=Psychology and the teacher|isbn =978-0826487155|publisher=]|year=2007|page=305|url=https://books.google.com/books?id=Jj8mAQAAIAAJ}}</ref> Average differences have been reported, however, on some tests of mathematics and verbal ability in certain contexts.<ref name="Mackintosh" /><ref name="Chrisler JC">{{cite book|url=https://books.google.com/books?id=Xtq0M1f_aIMC&pg=PA302|title=Handbook of Gender Research in Psychology: Volume 1: Gender Research in General and Experimental Psychology|vauthors=Chrisler JC, McCreary DR|publisher=]|year=2010|isbn=978-1441914651|page=302}}</ref><ref name="Terry" /> Some studies have suggested that there may be more variability in cognitive ability among males than among females,<ref name="Chrisler JC" /> but others have contradicted this,<ref name=":4" /> or presented evidence that differential variability is culturally rather than biologically determined.<ref name=":8" /> According to psychologist ], "there are both differences and similarities in the cognitive abilities of women and men, but there is no data-based rationale to support the idea that either is the smarter or superior sex."<ref name=":7" />
In 1875, ] argued that women were incapable of abstract thought and could not understand issues of justice, and only had the ability to understand issues of care.<ref name="Worell">Judith Worell, Encyclopedia of women and gender: sex similarities and differences and the impact of society on gender, Volume 1, Elsevier, 2001, ISBN 0-12-227246-3, ISBN 978-0-12-227246-2{{page needed|date=June 2013}}</ref> In 1925, ] also concluded that women were less morally developed in the concept of justice, and, unlike men, were more influenced by feeling than rational thought.<ref name="Worell"/> Early brain studies comparing mass and volumes between the sexes concluded that women were intellectually inferior because they had smaller and lighter brains (in reality, both genders are equally ], having the same brain-to-body mass ratio, but women have a smaller mean body mass).<ref name="Fine">{{cite book|last=Fine|first=Cordelia|authorlink=Cordelia Fine|title = ]| publisher =W. W. Norton|year=2010|isbn=0-393-06838-2}}{{page needed|date=June 2013}}</ref> Many believed that the size difference caused women to be excitable, emotional, sensitive, and therefore not suited for political participation.<ref name="Grandner"/>


=== Findings ===
In the nineteenth century, whether men and women had equal intelligence was seen by many as a prerequisite for the granting of ].<ref name="Grandner">Margarete Grandner, Austrian women in the nineteenth and twentieth centuries: cross-disciplinary perspectives, Berghahn Books, 1996, ISBN 1-57181-045-5, ISBN 978-1-57181-045-8</ref> ] argues that women were not permitted to realize their full ], as they were confined to the roles of child-rearing and ].
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Although most tests show no sex difference, there are some that do. For example, it has been found that female subjects tend to perform better on tests of verbal abilities and processing speed while males tend to perform better on tests of visual-spatial ability and ].<ref name=":10" /><ref name=":2" /> For verbal fluency, females have been specifically found to perform slightly better, on average, in vocabulary and reading comprehension and significantly higher in speech production and essay writing.<ref name=":0">{{cite book |last1=Hyde |first1=Janet Shibley |title=Biological, Social, and Organizational Components of Success for Women in Academic Science and Engineering: Report of a Workshop |date=2006 |publisher=National Academies Press |isbn=978-0-309-10041-0 |pages=127–137 |chapter=Women in Science and Mathematics: Gender Similarities in Abilities and Sociocultural Forces |chapter-url=https://www.ncbi.nlm.nih.gov/books/NBK23762/}}</ref> Males have been specifically found to perform better, on average, in spatial visualization, spatial perception, and mental rotation.<ref name=":0" /> None of these findings, however, suggest an advantage for either sex in ],<ref name=":2" /> nor in ].<ref name=":10" />
During the early twentieth century, the scientific consensus shifted to the view that gender plays no role in intelligence.<ref>{{cite journal | last1 = Burt | first1 = C. L. | last2 = Moore | first2 = R. C. | year = 1912 | title = The mental differences between the sexes | url = | journal = Journal of Experimental Pedagogy | volume = 1 | issue = 273–284| pages = 355–388 }}</ref> In his 1916 study of children's ]s, psychologist ] concluded that "the intelligence of girls, at least up to 14 years, does not differ materially from that of boys". He did, however, find "rather marked" differences on a minority of tests. For example, he found boys were "decidedly better" in arithmetical reasoning, while girls were "superior" at answering comprehension questions. He also proposed that discrimination, lack of opportunity, women's responsibilities in motherhood, or emotional factors may have accounted for the fact that few women had careers in intellectual fields.<ref name="Terman">{{cite book |last=Terman |first=Lewis M. |year=1916 |title=The measurement of intelligence: an explanation of and a complete guide for the use of the Stanford revision and extension of the Binet-Simon intelligence scale |publisher=Houghton Mifflin |location=Boston |pages=68–72 |oclc=186102}}</ref>


Most studies find either a very small difference or no sex difference with regard to general intelligence.<ref name="Hunt 2" /><ref name="Nyborg">{{cite book |doi=10.1016/B978-0-08-043793-4.X5033-8 |title=The Scientific Study of General Intelligence |year=2003 |isbn=9780080437934 }}</ref> In 2000, researchers ] and Francisco J. Abad conducted a large study of 10,475 adults on five IQ tests taken from the Primary Mental Abilities and found negligible or no significant sex differences. The tests conducted were on vocabulary, spatial rotation, verbal fluency and inductive reasoning.<ref name="Nyborg" />
== Current research on general intelligence ==


The literature on sex differences in intelligence has produced inconsistent results due to the type of testing used, and this has resulted in debate among researchers.<ref name="Chamorro-Premuzic">{{cite book |last1=Chamorro-Premuzic |first1=Tomas |url=https://books.google.com/books?id=F_SyBwAAQBAJ&pg=PA346 |title=The Wiley-Blackwell Handbook of Individual Differences |last2=Stumm |first2=Sophie von |last3=Furnham |first3=Adrian |publisher=] |year=2015 |isbn=978-1119050308 |pages=346, 363 |author2-link=Sophie von Stumm}}</ref> Garcia (2002) argues that there might be a small insignificant sex difference in ''intelligence in general'' (IQ) but this may not necessarily reflect a sex difference in ''general intelligence'' or ''g'' factor.<ref name="Chamorro-Premuzic" /> Although most researchers distinguish between ''g'' and IQ, those that argued for greater male intelligence asserted that IQ and ''g'' are synonymous (Lynn & Irwing 2004) and so the real division comes from defining IQ in relation to ''g'' factor. In 2008, Lynn and Irwing proposed that since ] ability correlates highest with ''g'' factor, researchers would have no choice but to accept greater male intelligence if differences on working memory tasks are found. As a result, a ] study published by Schmidt (2009) conducted an investigation into this proposal by measuring sex differences on an ] working memory task. The results found no sex difference in working memory capacity, thus contradicting the position put forward by Lynn and Irwing (2008) and more in line with those arguing for no sex differences in intelligence.<ref name="Chamorro-Premuzic" />
According to the 1994 report "]" by the ], "Most standard tests of intelligence have been constructed so that there are no overall score differences between females and males." Differences have been found, however, in specific areas such as mathematics and verbal measures.<ref name="lrainc.com">{{cite journal |doi=10.1037/0003-066X.51.2.77 |title=Intelligence: Knowns and Unknowns |year=1996 |last1=Neisser |first1=Ulric |last2=Boodoo |first2=Gwyneth |last3=Bouchard |first3=Thomas J., Jr. |last4=Boykin |first4=A. Wade |last5=Brody |first5=Nathan |last6=Ceci |first6=Stephen J. |last7=Halpern |first7=Diane F. |last8=Loehlin |first8=John C. |last9=Perloff |first9=Robert |journal=American Psychologist |volume=51 |issue=2 |pages=77–101 }}</ref>


A 2012 review by researchers ], ], ], ], ], ] and ] discussed ]'s 1998 studies on sex differences in intelligence. Jensen's tests were significantly g-loaded but were not set up to get rid of any sex differences (''read ]''). They summarized his conclusions finding "No evidence was found for sex differences in the mean level of g or in the variability of g. Males, on average, excel on some factors; females on others." Jensen's conclusion that no overall sex differences existed for ''g'' has been reinforced by researchers who analyzed this issue with a battery of 42 mental ability tests among adults and found no sex difference.<ref name=":2">{{cite journal |last1=Nisbett |first1=Richard E. |last2=Aronson |first2=Joshua |last3=Blair |first3=Clancy |last4=Dickens |first4=William |last5=Flynn |first5=James |last6=Halpern |first6=Diane F. |last7=Turkheimer |first7=Eric |title=Intelligence: New findings and theoretical developments |journal=American Psychologist |date=February 2012 |volume=67 |issue=2 |pages=130–159 |doi=10.1037/a0026699 |pmid=22233090 }}</ref>
When standardized IQ tests were first developed in the early 20th century, girls typically scored higher than boys until age 14, at which time the curve for girls dropped below that for boys.<ref name="Terman"/><ref name=Rider>{{cite book|last=Rider|first=Elizabeth A.|title=Our Voices: Psychology of Women|year=2000|publisher=Wadsworth|location=Belmont, California|isbn=0-534-34681-2|page=202}}</ref> As testing methodology was revised, efforts were made to equalize gender performance.<ref name=Rider/><ref>Archer, John, Barbara Bloom Lloyd, ''Sex and Gender'', Cambridge University Press, 2002, ISBN 0-521-63533-0, ISBN 978-0-521-63533-2{{page needed|date=June 2013}}</ref><ref>Sternberg, Robert J., ''Handbook of Intelligence'', Cambridge University Press, 2000, ISBN 0-521-59648-3{{page needed|date=June 2013}}</ref>


A large analysis by five researchers with a representative sample size of over 15,000 participants found no support for sex differences in IQ, neither among children nor among adults.<ref>{{cite journal |last1=Iliescu |first1=Dragos |last2=Ilie |first2=Alexandra |last3=Ispas |first3=Dan |last4=Dobrean |first4=Anca |last5=Clinciu |first5=Aurel Ion |title=Sex differences in intelligence: A multi-measure approach using nationally representative samples from Romania |journal=Intelligence |date=September 2016 |volume=58 |pages=54–61 |doi=10.1016/j.intell.2016.06.007 }}</ref>
The mean IQ scores between men and women vary little.<ref name="lrainc.com"/><ref name="Baumeister1">{{cite book| first =Roy F|last = Baumeister|title = Social psychology and human sexuality: essential readings|publisher = Psychology Press|year=2001 | isbn=978-1-84169-019-3}}{{page needed|date=June 2013}}</ref><ref name="Baumeister2">{{cite book| first =Roy F.|last = Baumeister|title = Is there anything good about men?: how cuflourish by exploiting men | publisher = Oxford University Press |year=2010 | isbn=978-0-19-537410-0}}{{page needed|date=June 2013}}</ref><ref name="Hedges and Nowell">{{cite journal |doi=10.1126/science.7604277 |title=Sex differences in mental test scores, variability, and numbers of high-scoring individuals |year=1995 |last1=Hedges |first1=L. |last2=Nowell |first2=A |journal=Science |volume=269 |issue=5220 |pages=41–5 |pmid=7604277|bibcode = 1995Sci...269...41H }}</ref><ref name="Colom2002">{{cite journal |pmid=12025362 |year=2002 |last1=Colom |first1=R |last2=García |first2=LF |last3=Juan-Espinosa |first3=M |last4=Abad |first4=FJ |title=Null sex differences in general intelligence: Evidence from the WAIS-III |volume=5 |issue=1 |pages=29–35 |journal=The Spanish journal of psychology |doi=10.1017/s1138741600005801}}</ref> The variability of male scores is greater than that of females, however, resulting in more males than females in the top and bottom of the IQ distribution.<ref name="Deary">{{cite journal |doi=10.1016/j.intell.2006.09.003 |title=Brother–sister differences in the ''g'' factor in intelligence: Analysis of full, opposite-sex siblings from the NLSY1979 |year=2007 |last1=Deary |first1=Ian J. |last2=Irwing |first2=Paul |last3=Der |first3=Geoff |last4=Bates |first4=Timothy C. |journal=Intelligence |volume=35 |issue=5 |pages=451–6}}</ref>


A 2022 meta-analysis found that even small sex-based differences in general intelligence were an artifact of older tests, with current test batteries showing no statistically significant difference between the sexes, but that differences in intelligence sub-types such as processing speed (favoring females) and visual-spatial reasoning (favoring males) remained even when controlling for test age.<ref name=":10">{{Cite journal |last1=Giofrè |first1=D. |last2=Allen |first2=K. |last3=Toffalini |first3=E. |last4=Caviola |first4=S. |date=22 September 2022 |title=The Impasse on Gender Differences in Intelligence: a Meta-Analysis on WISC Batteries |journal=Educational Psychology Review |volume=34 |issue=4 |pages=2543–2568|doi=10.1007/s10648-022-09705-1 |hdl=11567/1107935 |hdl-access=free }}</ref>
Several ] by ] between 1994 and 2005 found mean IQ of men exceeding that of women by a range of 3–5 points.<ref name="Lynn2004">{{cite journal |doi=10.1016/S0160-2896(99)00009-4 |title=Sex differences in intelligence and brain size: A developmental theory |year=1999 |last1=Lynn |first1=Richard |journal=Intelligence |volume=27 |pages=1–12}}</ref><ref name="Lynn2005">{{cite journal |doi=10.1348/000712605X53542 |title=Sex differences in means and variability on the progressive matrices in university students: A meta-analysis |year=2005 |last1=Irwing |first1=Paul |last2=Lynn |first2=Richard |journal=British Journal of Psychology |volume=96 |issue=4 |pages=505–24 |pmid=16248939}}</ref><ref name="ReferenceB"/><ref>{{cite journal |doi=10.1016/j.intell.2004.06.008 |title=Sex differences on the progressive matrices: A meta-analysis |year=2004 |last1=Lynn |first1=Richard |last2=Irwing |first2=Paul |journal=Intelligence |volume=32 |issue=5 |pages=481–498}}</ref> Lynn's findings were debated in a series of articles for '']''.<ref name="Intelligence: A gender bender"/><ref name="ReferenceC"/> Jackson and Rushton found males aged 17–18 years had average of 3.63 IQ points in excess of their female equivalents.<ref name="Jackson and Rushton">{{cite journal |doi=10.1016/j.intell.2006.03.005 |title=Males have greater g: Sex differences in general mental ability from 100,000 17- to 18-year-olds on the Scholastic Assessment Test |year=2006 |last1=Jackson |first1=Douglas N. |last2=Rushton |first2=J. Philippe |journal=Intelligence |volume=34 |issue=5 |pages=479–486}}</ref> A 2005 study by ] found an average advantage for males of 3.8 IQ points.<ref name="Nyborg2005">{{cite journal |doi=10.1016/j.paid.2004.12.011 |title=Sex-related differences in general intelligence ''g'', brain size, and social status |year=2005 |last1=Nyborg |first1=Helmuth |journal=Personality and Individual Differences |volume=39 |issue=3 |pages=497–509}}</ref> One study concluded that after controlling for sociodemographic and health variables, "] differences tended to disappear on tests for which there was a male advantage and to magnify on tests for which there was a female advantage."<ref name="jorm">{{cite journal |doi=10.1016/j.intell.2003.08.001 |title=Gender differences in cognitive abilities: The mediating role of health state and health habits |year=2004 |last1=Jorm |first1=Anthony F. |last2=Anstey |first2=Kaarin J. |last3=Christensen |first3=Helen |last4=Rodgers |first4=Bryan |journal=Intelligence |volume=32 |pages=7–23}}</ref> A study from 2007 found a 2-4 IQ point advantage for females in later life.<ref>{{cite journal |doi=10.1016/j.intell.2007.11.001 |title=Sex differences in latent cognitive abilities ages 6 to 59: Evidence from the Woodcock–Johnson III tests of cognitive abilities |year=2008 |last1=Keith |first1=Timothy Z. |last2=Reynolds |first2=Matthew R. |last3=Patel |first3=Puja G. |last4=Ridley |first4=Kristen P. |journal=Intelligence |volume=36 |issue=6 |pages=502–25}}</ref> One study investigated the differences in IQ between the sexes in relation to age, finding that girls do better at younger ages but that their performance declines relative to boys with age.<ref name="ColomLynn2004">{{cite journal |doi=10.1016/S0191-8869(03)00053-9 |title=Testing the developmental theory of sex differences in intelligence on 12–18 year olds |year=2004 |last1=Colom |first1=Roberto |last2=Lynn |first2=Richard |journal=Personality and Individual Differences |volume=36 |pages=75–82}}</ref> Colom et al. (2002) found 3.16 higher IQ points for males but no difference on the ] (''g'') and therefore explained the differences as due to non-''g'' factors such as specific group factors and test specificity.<ref name="Colom2002"/> A study conducted by ] and Lilia Rossi-Case (2011) found that men and women achieved roughly equal IQ scores on ] after reviewing recent standardization samples in five modernized nations.<ref name="flynn">{{cite journal |doi=10.1016/j.paid.2010.12.035 |title=Modern women match men on Raven's Progressive Matrices |year=2011 |last1=Flynn |first1=Jim |authorlink1=Jim Flynn (academic) |last2=Rossi-Casé |first2=Lilia |journal=Personality and Individual Differences |volume=50 |issue=6 |pages=799–803}}</ref> Irwing (2012) found a 3 point IQ advantage for males in ''g'' from subjects aged 16–89 in the United States.<ref>{{cite journal |doi=10.1016/j.paid.2011.05.001 |title=Sex differences in ''g'': An analysis of the US standardization sample of the WAIS-III |year=2012 |last1=Irwing |first1=Paul |journal=Personality and Individual Differences |volume=53 |issue=2 |pages=126–31}}</ref>


=== Variability ===
Differences in brain physiology between sexes do not necessarily relate to differences in intellect. Haier et al. found in a 2004 study that: "Men and women apparently achieve similar IQ results with different brain regions, suggesting that there is no singular underlying neuroanatomical structure to general intelligence and that different types of brain designs may manifest equivalent intellectual performance.<ref name=Haier>{{cite journal |doi=10.1016/j.neuroimage.2004.11.019 |title=The neuroanatomy of general intelligence: Sex matters |year=2005 |last1=Haier |first1=Richard J. |last2=Jung |first2=Rex E. |last3=Yeo |first3=Ronald A. |last4=Head |first4=Kevin |last5=Alkire |first5=Michael T. |journal=NeuroImage |volume=25 |pages=320–7 |pmid=15734366 |issue=1}}</ref> For men, the gray matter volume in the ] and ]s correlates with IQ; for women, the gray matter volume in the frontal lobe and ] (which is used in language processing) correlates with IQ.<ref name=Cosgrave2007>{{cite journal |doi=10.1016/j.biopsych.2007.03.001 |title=Evolving Knowledge of Sex Differences in Brain Structure, Function, and Chemistry |year=2007 |last1=Cosgrove |first1=Kelly P. |last2=Mazure |first2=Carolyn M. |last3=Staley |first3=Julie K. |journal=Biological Psychiatry |volume=62 |issue=8 |pages=847–55 |pmid=17544382 |pmc=2711771}}</ref>
{{Main|Variability hypothesis}}
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Some studies have identified the degree of IQ ] as a difference between males and females. Some researchers have argued that males tend to show greater variability on many traits, a view which is termed the ]; for example, having both highest and lowest scores on tests of cognitive abilities.<ref name="Chrisler JC" /> Other research has been published which contradicts this hypothesis, however, showing either equal variability between the sexes in some cultural contexts or else greater representation of females at the upper extreme of some measures of cognitive ability.<ref name=":9">{{Cite book|last1=Bosson|first1=Jennifer K.|title=The Psychology of Sex and Gender|last2=Buckner|first2=Camille E.|last3=Vandello|first3=Joseph A.|publisher=SAGE Publications|year=2020|isbn=978-1544394015|location=New York|pages=250–251}}</ref>
Some studies have identified the degree of IQ ] as a difference between males and females. Males tend to show greater variability on many traits including tests of cognitive abilities,<ref name="WaiCacchio2010">{{cite journal|last1=Wai|first1=Jonathan|last2=Cacchio|first2=Megan|last3=Putallaz|first3=Martha|last4=Makel|first4=Matthew C.|title=Sex differences in the right tail of cognitive abilities: A 30year examination|journal=Intelligence|volume=38|issue=4|year=2010|pages=412–423|issn=01602896|doi=10.1016/j.intell.2010.04.006}}</ref><ref name="Lehrke, R. 1997">Lehrke, R. (1997). Sex linkage of intelligence: The X-Factor. NY: Praeger.{{page needed|date=June 2013}}</ref><ref name="Lubinski, D. 2006">{{cite journal |doi=10.1111/j.1745-6916.2006.00019.x |title=Study of Mathematically Precocious Youth After 35 Years: Uncovering Antecedents for the Development of Math-Science Expertise |year=2006 |last1=Lubinski |first1=D. |last2=Benbow |first2=C. P. |journal=Perspectives on Psychological Science |volume=1 |issue=4 |pages=316–45 |jstor=40212176}}</ref> though this may differ between countries.<ref name="Hyde and Metz"/><ref>{{cite journal |bibcode=1995Sci...269...41H |title=Sex Differences in Mental Test Scores, Variability, and Numbers of High-Scoring Individuals |author1=Hedges |first1=Larry V. |last2=Nowell |first2=Amy |volume=269 |year=1995 |pages=41–5 |journal=Science |doi=10.1126/science.7604277 |pmid=7604277 |issue=5220}}</ref><ref>{{cite journal |pmid=20929039 |year=2009 |last1=Ali |first1=MS |last2=Suliman |first2=MI |last3=Kareem |first3=A |last4=Iqbal |first4=M |title=Comparison of gender performance on an intelligence test among medical students |volume=21 |issue=3 |pages=163–5 |journal=Journal of Ayub Medical College, Abbottabad}}</ref> A 2005 study by ], ], Geoff Der, and ], focusing on the ] showed a significantly higher ] in male scores, resulting in more than twice as many men as women scoring in the top 2%. The study also found a very small (] ≈ 0.07, less than 7%, of a ]) average male advantage in ].<ref name="Deary"/> A 2006 study by Rosalind Arden and ] focused on children aged 2, 3, 4, 7, 9 and 10 and stated that there was greater variance "among boys at every age except age two despite the girls’ mean advantage from ages two to seven. Girls are significantly over-represented, as measured by chi-square tests, at the high tail and boys at the low tail at ages 2, 3 and 4. By age 10 the boys have a higher mean, greater variance and are over-represented in the high tail."<ref name="Plomin2006">{{cite journal |doi=10.1016/j.paid.2005.11.027 |title=Sex differences in variance of intelligence across childhood |year=2006 |last1=Arden |first1=Rosalind |last2=Plomin |first2=Robert |journal=Personality and Individual Differences |volume=41 |pages=39–48}}</ref>


Feingold (1992) and Hedges and Nowell (1995) reported that, despite average sex differences being small and relatively stable over time, test score variances of males were generally larger than those of females.<ref name=":6">{{Cite book|title = Sex and Gender|url = https://archive.org/details/sexgender0000arch_l8q2|url-access = registration|pages=–188|publisher = Cambridge University Press|date = 2002-07-11|isbn = 9780521635332|first1 = John|last1 = Archer|first2 = Barbara|last2 = Lloyd}}</ref> Feingold "found that males were more variable than females on tests of quantitative reasoning, spatial visualisation, spelling, and general knowledge. ... Hedges and Nowell go one step further and demonstrate that, with the exception of performance on tests of reading comprehension, perceptual speed, and associative memory, more males than females were observed among high-scoring individuals."<ref name=":6" />
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|quote= The variability hypothesis still evokes controversy, but recent data and analyses may bring some closure to the debate Data from a number of representative mental test surveys, involving samples drawn from the national population, have become available in the past twenty years in the USA. These have finally provided consistent results. Both Feingold (1992b) and Hedges and Nowell (1995) have reported that, despite average sex differences being small and relatively stable over time, test score variances of males were generally larger than those of females. Feingold found that males were more variable than females on tests of quantitative reasoning, spatial visualisation, spelling, and general knowledge. Hedges and Nowell go one step further and demonstrate that, with the exception of performance on tests of reading comprehension, perceptual speed, and associative memory, more males than females were observed among high-scoring individuals.
|source=John Archer and Barbara Lloyd<ref>{{Cite book|last1=Archer|first1=John|last2=Lloyd|first2=Barbara|year=2002|title=Sex and Gender|edition=2nd|location=Cambridge|publisher=]|pages=}}</ref>
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In regards to variability in mathematics performance, a meta-analysis by Lindberg et al. (2010) found male-to-female variance ratios ranged from 0.88 to 1.34 across studies with an average of 1.07, indicating nearly equivalent male and female variances.<ref name=":4" /> The authors note that greater male variability is not ubiquitous, and ratios less than 1.0 have been reported in some national and international data sets.<ref name=":4" /> A review by Hyde et al. (2009) also evaluated the topic of greater male variability in mathematics performance.<ref name=":8">{{Cite journal|last1=Hyde|first1=Janet S.|last2=Mertz|first2=Janet E.|date=2009-06-02|title=Gender, culture, and mathematics performance|journal=Proceedings of the National Academy of Sciences of the United States of America|volume=106|issue=22|pages=8801–8807|doi=10.1073/pnas.0901265106|issn=0027-8424|pmc=2689999|pmid=19487665|bibcode=2009PNAS..106.8801H|doi-access=free}}</ref> The review found that the gender gap among the highest performers has narrowed over time in the U.S., is not found among some ethnic groups and in some nations, and correlates with several measures of gender inequality.<ref name=":8" /> The authors conclude that greater male variability in math performance is largely an artifact of cultural factors as opposed to innate biological sex differences.<ref name=":8" />
Another study on intelligence came up with similar findings. Young adolescents were asked to volunteer in this study and completed various assessments including ones looking at language, math, and sciences skills as well as the Toulous-Pieron test of attention and the Dominoes test.<ref name="Aluja-Fabregat, A. 2000">{{cite journal |doi=10.1016/S0191-8869(99)00142-7 |title=Sex differences in general intelligence defined as ''g'' among young adolescents |year=2000 |last1=Aluja-Fabregat |first1=Anton |last2=Colom |first2=Roberto |last3=Abad |first3=Francisco |last4=Juan-Espinosa |first4=Manuel |journal=Personality and Individual Differences |volume=28 |issue=4 |pages=813–20}}</ref> While one sample of children completed these assessments, another sample completed these plus another handful. The test results from both samples show a null sex difference in general intelligence in young adolescents. Researchers concluded that since g does not differ through academic and cognitive abilities in young adolescents, male or female, and that some other factor must be responsible for the variance between the sexes.<ref name="Aluja-Fabregat, A. 2000" />


== Brain and intelligence ==
A 2008 study with a sample of 6818 adults and children from 6 to 59 found different results on the ] IQ test. The study showed a moderate mean difference favouring females on the latent processing speed (Gs)factor, and a small difference favoring males on the latent comprehension–knowledge (Gc) factor.Males also showed an advantage on latent visual–spatial reasoning (Gv)and latent quantitative reasoning (RQ) factor. The latent overall ] factor was inconsistent in children, small but not significant differences favoring females during adolescence, and consistent differences favoring females during adulthood. There were no gender differences in latent long-term retrieval (Glr),short-term memory (Gsm), auditory proces-sing (Ga) and fluid reasoning (Gf) variables. The finding of the study is a matter of fact inconsistent with Lynn's developmental theory that by 16 males should have about 4 points IQ difference over females. Professor and lead researcher Timothy Keith suggests past research like Lynn's had instead used composite scores to calculate ] which may be prone to error, and so further research on latent factors are needed in the future.<ref>{{Cite journal|title = Sex differences in latent cognitive abilities ages 6 to 59: Evidence from the Woodcock–Johnson III tests of cognitive abilities|url = http://www.researchgate.net/publication/222660770_Sex_differences_in_latent_cognitive_abilities_ages_6_to_59_Evidence_from_the_WoodcockJohnson_III_tests_of_cognitive_abilities|journal = Intelligence|pages = 502–525|volume = 36|issue = 6|doi = 10.1016/j.intell.2007.11.001|first = Timothy Z.|last = Keith|first2 = Matthew R.|last2 = Reynolds|first3 = Puja G.|last3 = Patel|first4 = Kristen P.|last4 = Ridley}}</ref>
{{see also|Neuroscience of sex differences}}
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Differences in brain physiology between sexes do not necessarily relate to differences in intellect. Although men have larger brains, men and women have equal IQs.<ref name="Kalat">{{cite book|vauthors=Kalat JW|title=Biological Psychology|isbn =978-1111831004|publisher=]|year=2012|pages=118, 120|url=https://books.google.com/books?id=evbdjAQYA1cC&pg=PA118}}</ref> For men, the gray matter volume in the ] and ]s correlates with IQ; for women, the gray matter volume in the frontal lobe and ] (which is used in language processing) correlates with IQ.<ref name="Garrett">{{cite book|vauthors=Garrett B, Hough G|title=Brain & Behavior: An Introduction to Behavioral Neuroscience|isbn =978-1506349190|publisher=]|year=2017|page=118|url=https://books.google.com/books?id=4Xg4DwAAQBAJ&pg=PA377}}</ref> Women have greater cortical thickness, ] and cortical surface area (controlling for body size) which compensates for smaller ].<ref>{{Cite book|title = Sex difference in the human brain, their underpinnings and implications|url = https://books.google.com/books?id=JFpq6hYQRhQC&pg=PA6|publisher = ]|date =2010 |isbn = 9780444536310|pages=6–7|language = en}}</ref> Meta-analysis and studies have found that brain size explains 6–12% of variance among individual intelligence and cortical thickness explains 5%.<ref name="Pietschnig">{{Cite journal|title = Meta-analysis of associations between human brain volume and intelligence differences: How strong are they and what do they mean?|journal = Neuroscience & Biobehavioral Reviews|date = 2015-10-01|pages = 411–432|volume = 57|doi = 10.1016/j.neubiorev.2015.09.017|first1 = Jakob|last1 = Pietschnig|first2 = Lars|last2 = Penke|first3 = Jelte M.|last3 = Wicherts|first4 = Michael|last4 = Zeiler|first5 = Martin|last5 = Voracek|pmid=26449760|s2cid = 23180321}}</ref>
It was believed at one point that Gf, or fluid intelligence, can be used to systematically detect sex differences in general intelligence if there are any.<ref name="Colom, R. 2002">{{cite journal |doi=10.1016/S0191-8869(01)00040-X |title=Sex differences in fluid intelligence among high school graduates |year=2002 |last1=Colom |first1=Roberto |last2=Garcı́a-López |first2=Oscar |journal=Personality and Individual Differences |volume=32 |issue=3 |pages=445–451}}</ref> The PMA Inductive Reasoning Test, Cattell’s Culture-Fair Intelligence Test, and the Advanced Progressive Matrices were used to test a group of about 4000 high school graduates. Through the results of these tests, researchers discovered that females perform better in the PMA Inductive Reasoning Test and males perform better in the Advanced Progressive Matrices assessment.<ref name="Colom, R. 2002" /> There was no sex difference noted from the results of the Culture-Fair Test. Sex difference in fluid intelligence was proven to not exist in this study.<ref name="Colom, R. 2002" />


Although a meta-analysis of 148 samples from over 8000 participants reported a weak correlation between brain size and IQ,<ref name="Pietschnig" /> men and women did not differ in IQ, and the researchers concluded that "it is not warranted to interpret brain size as an isomorphic proxy of human intelligence differences."<ref name="Pietschnig" /> Brain volume contributes little to IQ test performance. Outside of comparing intelligence levels of the sexes, brain size is only one of numerous factors that influence intelligence, alongside white matter integrity, overall developmental stability, parieto-frontal neuronal networks, neuronal efficiency, and cortical ]. Brain structural integrity seems to be more important as a biological basis.<ref name="Pietschnig" />
In a 2012 review by 6 prominent researchers, they addressed ]'s 1998 studies on sex differences in intelligence in tests that were “loaded heavily on ]” but were not set-up to eliminate sex differences(since most tests are set-up to eliminate unnecessary differences). They summarized that his conclusions were as he quoted "''No evidence was found for sex differences in the mean level of g or in the variability of g''.''Males, on average,excel on some factors; females on others''”. Jensen’s results that no overall sex differences existed for ] has been strengthened by researchers who assessed this issue with a battery of 42 mental ability tests and found no overall sex difference.<ref name=":2">{{Cite journal|url = http://www.apa.org/pubs/journals/releases/amp-67-2-130.pdf|title = Intelligence New Findings and Theoretical Developments|last = Nisbet|first = Richard E|date = 2012|journal = Intelligence|doi = 10.1037/a0026699|pmid = |access-date = }}</ref>


In 2021, Lise Eliot et al found no difference in overall male/female abilities in verbal, spatial or emotion processing.<ref>{{cite journal |last1=Eliot |first1=Lise |last2=Ahmed |first2=Adnan |last3=Khan |first3=Hiba |last4=Patel |first4=Julie |title=Dump the 'dimorphism': Comprehensive synthesis of human brain studies reveals few male-female differences beyond size |journal=Neuroscience & Biobehavioral Reviews |date=June 2021 |volume=125 |pages=667–697 |doi=10.1016/j.neubiorev.2021.02.026 |doi-access=free }}</ref>
Although most of the tests showed no difference, there were some that did. For example, they found female performed better on verbal abilities while males performed better on visuospatial abilities.<ref name=":2" /> For verbal fluency, females have been specifically found to perform better in vocabulary, reading comprehension, speech production and essay writing.<ref name=":0">{{Cite journal|title = Women in Science and Mathematics|url = http://www.ncbi.nlm.nih.gov/books/NBK23762/|date = 2006-01-01|first = National Academy of Sciences|last = (us)|first2 = National Academy of Engineering|last2 = (us)|first3 = and Institute of Medicine (US) Committee on Maximizing the Potential of Women in Academic Science and|last3 = Engineering}}</ref> Males have been specifically found to perform better on spatial visualization, spatial perception, and mental rotation.<ref name=":0" /> Researchers had then recommended that general models such as ] and ] be divided into ], perceptual and ] domains of ], because when this model is applied then females excel at verbal and perceptual tasks while males on visuospatial tasks.<ref name=":2" /> Thus evening out the sex differences on IQ tests.

While research has shown that males and females do indeed each excel in different abilities, math and science might be an exception to this.<ref>{{cite journal |doi=10.1111/j.1529-1006.2007.00032.x |title=The Science of Sex Differences in Science and Mathematics |year=2007 |last1=Halpern |first1=Diane F. |last2=Benbow |first2=Camilla P. |last3=Geary |first3=David C. |last4=Gur |first4=Ruben C. |last5=Hyde |first5=Janet Shibley |last6=Gernsbacher |first6=Morton Ann |journal=Psychological Science in the Public Interest |volume=8 |pages=1–51}}</ref>


==Mathematics performance== ==Mathematics performance==
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] compete in the USS California Science Experience at Naval Surface Warfare Center Corona Division.]]


Across countries, males have performed better on ] tests than females, but there is the possibility male-female difference in math scores is related to ] in social roles.<ref name="Sternberg">{{cite book|vauthors=Sternberg RJ, Kaufman SB|title=The Cambridge Handbook of Intelligence|isbn =978-1111831004|publisher=]|year=2011|page=877|url=https://books.google.com/books?id=FtYeTcNwzQ4C&pg=PA877}}</ref> Some psychologists believe that many historical and current sex differences in mathematics performance may be related to boys' higher likelihood of receiving math encouragement than girls. Parents were, and sometimes still are, more likely to consider a son's mathematical achievement as being a natural skill while a daughter's mathematical achievement is more likely to be seen as something she studied hard for.<ref name="Wood, Samuel 2004">Wood, Samuel; Wood, Ellen; Boyd Denise (2004). "World of Psychology, The (Fifth Edition)", Allyn & Bacon {{ISBN|0-205-36137-4}}.{{page needed|date=September 2021}}</ref> This difference in attitude may discourage girls and women from further involvement in mathematics-related subjects and careers.<ref name="Wood, Samuel 2004" />
] compete in the USS California Science Experience at Naval Surface Warfare. In 2008, the ] reported that, on average, girls perform as well as boys on standardized math tests, while boys are overrepresented on both ends of the spectrum.]]


In a 2008 study paid for by the ] in the United States, researchers found that girls perform as well as boys on standardized math tests. They attributed this to girls now taking as many advanced math courses as boys, unlike in the past.<ref name="Davis">{{Cite book|last=Davis|first=Andrew S.|title=Handbook of Pediatric Neuropsychology|date=2010|publisher=Springer Publishing Company|isbn=978-0-82-615737-9|page=1089|url=https://books.google.com/books?id=SU9-LSh4HgcC&pg=PA1089}}</ref><ref name="Crooks">{{cite book|vauthors=Crooks RL, Baur K|title=Our Sexuality|isbn =978-1305887428|publisher=]|year=2016|page=125|url=https://books.google.com/books?id=isIaCgAAQBAJ&pg=PT157}}</ref>
Large, representative studies of US students show that no sex differences in ] performance exist before secondary school. During and after secondary school, historic sex differences in mathematics enrollment account for nearly all of the sex differences in mathematics performance. However, a performance difference in mathematics on the ] exists favoring males, though differences in mathematics course performance measures favor females.<ref name="Gallagher">Ann M. Gallagher, ], ''Gender differences in mathematics: an integrative psychological approach'', Cambridge University Press, 2005, ISBN 0-521-82605-5, ISBN 978-0-521-82605-1{{page needed|date=June 2013}}</ref> In 1983, Benbow concluded that the study showed a large sex difference by age 13 and that it was especially pronounced at the high end of the distribution.<ref>{{cite journal |doi=10.1126/science.6648516 |title=Sex differences in mathematical reasoning ability: More facts |year=1983 |last1=Benbow |first1=C. |last2=Stanley |first2=J. |journal=Science |volume=222 |issue=4627 |pages=1029–31 |pmid=6648516}}</ref> However, Gallagher and Kaufman criticized Benbow's and other reports finding males overrepresented in the highest percentages as not ensuring representative sampling.<ref name="Gallagher"/>


There is also evidence that boys are over-represented among the very best and very worst performers on measures of mathematical ability and standardized measures of IQ.<ref name="Davis"/> Some research suggests that differences in mathematics course performance measures favor females.<ref name="Gallagher">Ann M. Gallagher, ], ''Gender differences in mathematics: an integrative psychological approach'', Cambridge University Press, 2005, {{ISBN|0-521-82605-5}}, {{ISBN|978-0-521-82605-1}}{{page needed|date=June 2013}}</ref> A small performance difference in mathematics on the ]<ref>, p.196. ] 2015.</ref> persists in favor of males, though the gap has shrunk from 40 points (5.0%) in 1975<ref>{{cite journal |last1=Burton |first1=Nancy W. |last2=Lewis |first2=Charles |last3=Robertson |first3=Nancy |title=SEX DIFFERENCES IN SAT® SCORES |journal=ETS Research Report Series |date=December 1988 |volume=1988 |issue=2 |doi=10.1002/j.2330-8516.1988.tb00314.x }}</ref> to 18 points (2.3%) in 2020.<ref>{{Cite web|date=2021-09-08|title=2021 SAT Suite of Assessments Program Results – The College Board|url=https://reports.collegeboard.org/sat-suite-program-results|access-date=2021-09-16|website=College Board Program Results|language=en}}</ref> However, the SAT is not a representative sample, given that it tests only college-bound students, and more women than men have attended college since the 1990s.<ref>{{Cite journal|last1=Stoet|first1=Gijsbert|last2=Geary|first2=David C.|date=2020-06-23|title=Gender differences in the pathways to higher education|journal=Proceedings of the National Academy of Sciences|volume=117|issue=25|pages=14073–14076|doi=10.1073/pnas.2002861117|pmid=32513710|pmc=7322061|doi-access=free|bibcode=2020PNAS..11714073S }}</ref> Conversely, the international PISA exam provides representative samples. On the 2018 math PISA, there was no statistically significant difference between the performances of girls and boys in 39.5% of the 76 countries that participated. Meanwhile, boys outperformed girls in 32 countries (42.1%), while girls outperformed boys in 14 (18.4%).<ref name=":3">{{Cite web|title=Home|url=https://www.oecd-ilibrary.org/sites/f56f8c26-en/index.html?itemId=/content/component/f56f8c26-en|access-date=2021-09-16|website=www.oecd-ilibrary.org|language=en}}</ref> On average, boys performed 5 points (1%) higher than girls. However, overall, the gender gap in math and science for boys and girls from similar socio-economic backgrounds was not significant.<ref name=":3" />
In a 2008 study paid for by the ] in the United States, researchers found that "girls perform as well as boys on standardized ] tests. Although 20 years ago, high school boys performed better than girls in math, the researchers found that is no longer the case. The reason, they said, is simple: Girls used to take fewer advanced math courses than boys, but now they are taking just as many."<ref>Lewin, Tamar (July 25, 2008)., '']''.</ref><ref>{{cite journal |doi=10.1126/science.1160364 |title=DIVERSITY: Gender Similarities Characterize Math Performance |year=2008 |last1=Hyde |first1=J. S. |last2=Lindberg |first2=S. M. |last3=Linn |first3=M. C. |last4=Ellis |first4=A. B. |last5=Williams |first5=C. C. |journal=Science |volume=321 |issue=5888 |pages=494–5 |pmid=18653867}}</ref> However, the study indicated that, while on average boys and girls performed similarly, boys were overrepresented among the very best performers as well as among the very worst.<ref>Winstein, Keith J. (July 25, 2008). , '']'' (New York).</ref><ref>{{cite journal |doi=10.1111/1467-9280.00291 |title=Sex Differences in Mathematical Reasoning Ability at Age 13: Their Status 20 Years Later |year=2000 |last1=Benbow |first1=C. P. |last2=Lubinski |first2=D. |last3=Shea |first3=D. L. |last4=Eftekhari-Sanjani |first4=H. |journal=Psychological Science |volume=11 |issue=6 |pages=474–80 |pmid=11202492}}</ref> A 2011 meta-analysis with 242 studies from 1990 to 2007 involving 1,286,350 people found no overall sex difference of performance in Mathematics. The meta-analysis also found that although there were no overall differences, a small sex difference that favored males in complex problem solving is still present in high school.<ref>{{Cite journal|title = New Trends in Gender and Mathematics Performance: A Meta-Analysis|url = http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3057475/|journal = Psychological bulletin|date = 2010-11-01|issn = 0033-2909|pmc = 3057475|pmid = 21038941|pages = 1123–1135|volume = 136|issue = 6|doi = 10.1037/a0021276|first = Sara M.|last = Lindberg|first2 = Janet Shibley|last2 = Hyde|first3 = Jennifer L.|last3 = Petersen|first4 = Marcia C.|last4 = Linn}}</ref>


On the math portion of the 2019 TIMMS, taken at a similar age as the PISA, girls outperformed boys by 3 points on average, although the difference was not statistically significant.<ref>{{cite web | url=https://timss2019.org/reports/average-achievement-by-gender-m8/index.html#:~:text=In%20TIMSS%202019%2C%20there%20was,than%20girls%20in%206%20countries | title=TIMSS 2019 International Reports – TIMSS & PIRLS International Study Center at Boston College }}</ref> A meta-analysis of nearly half a million participants using data from both the TIMMS and the PISA found that differences were negligible, although girls outperfomed boys in some countries and the opposite occurred in others.<ref>{{cite web | url=https://www.scientificamerican.com/podcast/episode/no-gender-gap-in-math-10-01-06/ | title=No Gender Gap in Math | website=] }}</ref>
Kiefer and Sekaquaptewa proposed that a source of some women's underperformance and lowered perseverance in mathematical fields is these women's underlying "implicit" sex-based stereotypes regarding mathematical ability and association, as well as their identification with their gender.<ref> Science Daily (Jan 24, 2007).</ref> Some psychologists believe that many historical and current sex differences in mathematics performance may be related to boy's higher likelihood of receiving math encouragement than girls. Parents were, and sometimes still are, more likely to consider a son's mathematical achievement as being a natural skill while a daughter's mathematical achievement is more likely to be seen as something she studied hard for. This difference in attitude may contribute to girls and women being discouraged from further involvement in mathematics-related subjects and careers.<ref name="Wood, Samual 2004">Wood, Samual; Wood, Ellen; Boyd Denise (2004). "World of Psychology, The (Fifth Edition)" , Allyn & Bacon ISBN 0-205-36137-4</ref> ] has been shown to affect performance and confidence in mathematics of both males and females.<ref name="Fine"/><ref name="Gallagher"/> However, a review of stereotype threat literature found most studies couldn't be replicated or suffered methodological problems and concluded "that although stereotype threat may affect some women, the existing state of knowledge does not support the current level of enthusiasm for this as a mechanism underlying the gender gap in mathematics."<ref>{{cite journal |doi=10.1037/a0026617 |title=Can stereotype threat explain the gender gap in mathematics performance and achievement? |year=2012 |last1=Stoet |first1=Gijsbert |last2=Geary |first2=David C. |journal=Review of General Psychology |volume=16 |pages=93–102}}</ref>


A 2008 meta-analysis published in '']'' using data from over 7 million students found no statistically significant differences between the mathematical capabilities of males and females.<ref>{{Cite web|title=Study: No gender differences in math performance|url=https://news.wisc.edu/study-no-gender-differences-in-math-performance/|access-date=2021-09-16|website=news.wisc.edu|language=en-US}}</ref> A 2011 meta-analysis with 242 studies from 1990 to 2007 involving 1,286,350 people found no overall sex difference of performance in mathematics. The meta-analysis also found that although there were no overall differences, a small sex difference that favored males in complex problem solving was still present in high school. However, the authors note that boys continue to take more physics courses than girls, which train complex solving abilities and may provide stronger training than pure mathematics.<ref name=":4">{{cite journal|last1=Lindberg|first1=Sara M.|last2=Hyde|first2=Janet Shibley|last3=Petersen|first3=Jennifer L.|last4=Linn|first4=Marcia C.|date=2010|title=New trends in gender and mathematics performance: A meta-analysis.|journal=Psychological Bulletin|volume=136|issue=6|pages=1123–1135|doi=10.1037/a0021276|pmc=3057475|pmid=21038941}}</ref>
Two cross-country comparisons have found great variation in the gender differences regarding the degree of variance in mathematical ability. In most nations males have greater variance. In a few females have greater variance. Hyde and Mertz argue that boys and girls differ in the variance of their ability due to sociocultural factors.<ref name="Hyde and Metz">{{cite journal |doi=10.1073/pnas.0901265106 |title=Gender, culture, and mathematics performance |year=2009 |last1=Hyde |first1=J. S. |last2=Mertz |first2=J. E. |journal=Proceedings of the National Academy of Sciences |volume=106 |issue=22 |pages=8801–7|bibcode = 2009PNAS..106.8801H |pmid=19487665 |pmc=2689999}}</ref><ref>{{cite journal |doi=10.1086/589252 |title=Gender Differences in Extreme Mathematical Achievement: An International Perspective on Biological and Social Factors |year=2008 |last1=Penner |first1=Andrew&nbsp;M. |journal=American Journal of Sociology |volume=114 |pages=S138}}</ref><ref>{{cite journal |doi=10.1126/science.1162573 |title=ASSESSMENT: Global Sex Differences in Test Score Variability |year=2008 |last1=Machin |first1=S. |last2=Pekkarinen |first2=T. |journal=Science |volume=322 |issue=5906 |pages=1331–2 |pmid=19039123}}</ref>

The mathematics ] examination results in ] have often been inconsistent about which sex performed better. In 2008, 14.7% of females scored an A or above, while only 13.9% of males did the same. But in 2024, only 15.5% of females scored an A or above, while 18% of males did.<ref name="t540">{{cite web | title=GCSE outcomes in England | website=Ofqual | url=https://analytics.ofqual.gov.uk/apps/GCSE/Outcomes/ | access-date=2024-08-26}}</ref> A 2020 analysis of gender differences in the mathematical abilities of 13 million students in Italy found that males performed better at mathematics and that this difference appeared to increase the richer the Italian regions were, which is also characterized by greater gender equality.<ref name="y086">{{cite journal | last1=Giofrè | first1=D. | last2=Cornoldi | first2=C. | last3=Martini | first3=A. | last4=Toffalini | first4=E. | title=A population level analysis of the gender gap in mathematics: Results on over 13 million children using the INVALSI dataset | journal=Intelligence | publisher=Elsevier BV | volume=81 | year=2020 | issn=0160-2896 | doi=10.1016/j.intell.2020.101467 | doi-access=free | page=101467| arxiv=2112.11940 }}</ref>

One line of inquiry has focused on the role that ] might play in mathematics performance differences between male and female test-takers.<ref name="Gallagher" /> Systematic reviews and meta-analyses suggest that stereotype threat is implicated in performance differences on some mathematics tests, though the effect appears to vary considerably in different social contexts and for different test conditions.<ref name=":42">{{cite journal |vauthors=Nguyen HH, Ryan AM |date=November 2008 |title=Does stereotype threat affect test performance of minorities and women? A meta-analysis of experimental evidence |journal=The Journal of Applied Psychology |volume=93 |issue=6 |pages=1314–34 |doi=10.1037/a0012702 |pmid=19025250}}</ref><ref name=":52">{{Cite journal |last1=Walton |first1=Gregory M. |last2=Spencer |first2=Steven J. |date=2009-09-01 |title=Latent Ability: Grades and Test Scores Systematically Underestimate the Intellectual Ability of Negatively Stereotyped Students |journal=Psychological Science |volume=20 |issue=9 |pages=1132–1139 |doi=10.1111/j.1467-9280.2009.02417.x |issn=0956-7976 |pmid=19656335 |s2cid=25810191|doi-access=free }}</ref><ref name=":22">{{Cite journal |last1=Picho |first1=Katherine |last2=Rodriguez |first2=Ariel |last3=Finnie |first3=Lauren |date=May 2013 |title=Exploring the Moderating Role of Context on the Mathematics Performance of Females Under Stereotype Threat: A Meta-Analysis |url=https://www.researchgate.net/publication/237000996 |journal=The Journal of Social Psychology |volume=153 |issue=3 |pages=299–333 |doi=10.1080/00224545.2012.737380 |pmid=23724702 |s2cid=45950675}}</ref><ref>{{Cite journal |last=Pennington |first=Charlotte R. |date=2016-01-11 |title=Twenty Years of Stereotype Threat Research: A Review of Psychological Mediators |journal=]|volume=11 |issue=1 |pages=e0146487 |doi=10.1371/journal.pone.0146487 |pmid=26752551 |pmc=4713435 |bibcode=2016PLoSO..1146487P |doi-access=free }}</ref><ref name=":14">{{Cite journal |last1=Liu |first1=Songqi |last2=Liu |first2=Pei |last3=Wang |first3=Mo |last4=Zhang |first4=Baoshan |date=July 2020 |title=Effectiveness of Stereotype Threat Interventions: A Meta-Analytic Review |url=https://www.researchgate.net/publication/343149798 |journal=Journal of Applied Psychology |volume=106 |issue=6 |pages=921–949 |doi=10.1037/apl0000770 |pmid=32772526 |s2cid=221098319}}</ref>

== Reading and verbal skills ==
Studies have shown a female advantage in reading and verbal skills.<ref name="Hunt3">{{cite book|last1=Hunt|first1= Earl B.|author-link1=Earl B. Hunt|title =Human Intelligence|isbn =978-1139495110|publisher=]|year=2010|page=387|url=https://books.google.com/books?id=DwO4TtKAiCoC&pg=PA387}}</ref> On the international PISA reading exam, girls consistently outperform boys across all countries, and all differences are statistically significant. In the most recent PISA exam (2018), girls outperformed boys by almost 30 points.<ref>{{cite book |doi=10.1787/fb6da32e-en |chapter=PISA 2018 Data |title=PISA 2018 Results (Volume II) |date=2019 |isbn=978-92-64-89352-8 }}</ref> On average in OECD countries, 28% of boys did not obtain a reading proficiency level of 2.

Studies have shown that girls spend more time reading than boys and read more for fun, likely contributing to the gap.<ref>{{Cite journal|last1=Hughes-Hassell|first1=Sandra|last2=Rodge|first2=Pradnya|date=2007|title=The Leisure Reading Habits of Urban Adolescents|url=https://www.jstor.org/stable/40015543|journal=Journal of Adolescent & Adult Literacy|volume=51|issue=1|pages=22–33|doi=10.1598/JAAL.51.1.3|jstor=40015543|issn=1081-3004}}</ref> Some psychologists believe that many historical and current sex differences in mathematics performance may be related to girls' higher likelihood of receiving reading encouragement than boys. Parents were, and sometimes still are, more likely to consider a daughter's reading achievement as being a natural skill while a son's reading achievement is more likely to be seen as something he studied hard for.<ref name="Wood, Samuel 2004"/>


== Spatial ability == == Spatial ability ==
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] tests.]] ] tests]]
] ]
Meta-studies show a male advantage in ], assessing horizontality and verticality, and a male advantage for most aspects of ].<ref name=":1">{{cite journal |last1=Fernandez-Baizan |first1=C. |last2=Arias |first2=J.L. |last3=Mendez |first3=M. |title=Spatial memory in young adults: Gender differences in egocentric and allocentric performance |journal=Behavioural Brain Research |date=February 2019 |volume=359 |pages=694–700 |doi=10.1016/j.bbr.2018.09.017 |pmid=30273614 |hdl=10651/49938 |s2cid=52879258 |hdl-access=free }}</ref><ref name="Voyer">{{cite journal |last1=Voyer |first1=Daniel |last2=Voyer |first2=Susan D. |last3=Saint-Aubin |first3=Jean |title=Sex differences in visual-spatial working memory: A meta-analysis |journal=Psychonomic Bulletin & Review |date=April 2017 |volume=24 |issue=2 |pages=307–334 |doi=10.3758/s13423-016-1085-7 |pmid=27357955 |doi-access=free |quote=All the tasks produced a male advantage, except for memory for location, where a female advantage emerged.}}</ref><ref name="Chrisler">{{Cite book |last = Chrisler |first = Joan C|title = Handbook of Gender Research in Psychology|publisher = Springer|isbn = 9781441914644|author2=Donald R. McCreary|date=2010|page=265|url=https://books.google.com/books?id=Xtq0M1f_aIMC&pg=PA265}}</ref> Women have an advantage for certain components of spatial memory. Whereas men show a selective advantage for fine-grained metric positional reconstruction, where absolute spatial coordinates are emphasized, women show an advantage in spatial location memory, which is the ability to accurately remember relative object positions (where objects are);<ref name="Voyer" /><ref name="Becker">{{Cite book|last1= Becker |first1 = Jill B. |last2=Berkley|first2=Karen J.|last3= Geary|first3=Nori|last4=Hampson|first4=Elizabeth|last5=Herman|first5=James P. |last6= Young|first6=Elizabeth |title=Sex Differences in the Brain: From Genes to Behavior|date=2007|publisher=Oxford University Press|isbn =978-0198042556|page=316|url=https://books.google.com/books?id=IeaLXPWsbuAC&pg=PA316}}</ref><ref name="Bosson">{{Cite book|last1 = Bosson |first1 =Jennifer K.|last2=Buckner|first2=Camille E.|last3=Vandello|first3=Joseph A.|title=The Psychology of Sex and Gender|date=2021|publisher=SAGE Publications|isbn=978-1544394039|page=271|url=https://books.google.com/books?id=B74IEAAAQBAJ&pg=PT271}}</ref> however, the advantage in spatial location memory is small and inconsistent across studies.<ref name="Bosson" />


A proposed evolutionary hypothesis is that men and women evolved different mental abilities to adapt to their different roles, including labor-based roles, in society.<ref name="Bosson" /> For example, "ancestral women more often foraged for fruits, vegetables, and roots over large geographic regions."<ref name="Bosson" /> The labor-based role explanation suggests that men may have evolved greater spatial abilities as a result of behaviors such as navigating during a ].<ref name="Weiten, labor-based role">{{Cite book|last=Weiten|first=Wayne|title=Psychology: Themes and Variations|date=2016|publisher=Cengage Learning|isbn=978-1-30-585612-7|page=27|url=https://books.google.com/books?id=ALkaCgAAQBAJ&pg=PT77}}</ref>
Some studies investigating the spatial abilities of men and women have found no significant differences,<ref>Corley, DeFries, Kuse, Vandenberg. 1980. ''Familial Resemblance for the Identical Blocks Test of Spatial Ability: No Evidence of X Linkage''. Behavior Genetics.</ref><ref>Julia A. Sherman. 1978. Sex-Related Cognitive Differences: An Essay on Theory and Evidence Springfield.</ref> though metastudies show a male advantage in ] and assessing horizontality and verticality,<ref name="lrainc.com"/><ref name=Chrisler>{{Cite book |last = Chrisler |first = Joan C|title = Handbook of Gender Research in Psychology|publisher = Springer, 2010|isbn = 9781441914644|author2=Donald R. McCreary }}{{page needed|date=June 2013}}</ref> and a female advantage in ].<ref name="Halpern">Halpern, Diane F., Sex differences in cognitive abilities, Psychology Press, 2000, ISBN 0-8058-2792-7, ISBN 978-0-8058-2792-7{{page needed|date=June 2013}}</ref><ref name="Lee">Ellis, Lee, Sex differences: summarizing more than a century of scientific research, CRC Press, 2008, ISBN 0-8058-5959-4, ISBN 978-0-8058-5959-1{{page needed|date=June 2013}}</ref>


Sex differences in mental rotation and ] in favor of males have been observed across multiple nations, lending credence to biological origins, though countries with greater gender equality also had greater gaps in these areas, lending credence to possible social influence as well.<ref name="pmidhttps://pubmed.ncbi.nlm.nih.gov/19130205/">{{cite journal|vauthors=Lippa RA, Collaer ML, Peters M| title=Sex differences in mental rotation and line angle judgments are positively associated with gender equality and economic development across 53 nations. | journal=Arch Sex Behav | year= 2010 | volume= 39 | issue= 4 | pages= 990–7 | pmid=19130205 | doi=10.1007/s10508-008-9460-8}} </ref>
A proposed hypothesis is that men and women evolved different mental abilities to adapt to their different roles in society.<ref name="Eals, Marion 1992">Eals, Marion, and Irwin Silverman. 1992. Sex differences in spatial abilities: evolutionary theory and data. In The Adapted Mind: Evolutionary Psychology and the Generation of Culture, edited by J. H. Barkow. New York: Oxford University Press.{{page needed|date=June 2013}}</ref><ref>{{cite journal |doi=10.1098/rspb.2006.3572 |title=Differences in cue use and spatial memory in men and women |year=2006 |last1=Jones |first1=C. M |last2=Healy |first2=S. D |journal=Proceedings of the Royal Society B: Biological Sciences |volume=273 |issue=1598 |pages=2241–2247}}</ref> This explanation suggests that men may have evolved greater spatial abilities as a result of certain behaviors, such as navigating during a ].<ref name="Geary">{{cite book|last = Geary| first = David C.|authorlink = David C. Geary | title = Male, female: The evolution of human sex differences|publisher = American Psychological Association|year = 1998|isbn = 1-55798-527-8}}{{page needed|date=June 2013}}</ref> Similarly, this hypothesis suggests that women may have evolved to devote more mental resources to remembering locations of food sources in relation to objects and other features in order to gather food.<ref>{{cite journal |doi=10.1098/rspb.2007.0826 |title=Spatial adaptations for plant foraging: Women excel and calories count |year=2007 |last1=New |first1=J. |last2=Krasnow |first2=M. M |last3=Truxaw |first3=D. |last4=Gaulin |first4=S. J.C |journal=Proceedings of the Royal Society B: Biological Sciences |volume=274 |issue=1626 |pages=2679–2684}}</ref>


Results from studies conducted in the physical environment are not conclusive about sex differences. Various studies on the same task show no differences. There are studies that show no difference in finding one's way between two places.<ref name="Devlin">Devlin, Ann Sloan, Mind and maze: spatial cognition and environmental behavior, Praeger, 2001, {{ISBN|0-275-96784-0}}, {{ISBN|978-0-275-96784-0}}{{page needed|date=June 2013}}</ref>
A number of studies have shown that women tend to rely more on visual information than men in a number of spatial tasks related to perceived orientation.<ref>Witkin, H. A., Lewis, H. B., Hertzman, M., Machover, K., Meissner, P. B. & Wapner, S. (1954) Personality Through Perception. An Experimental and Clinical Study. Harper, New York.</ref><ref>{{cite journal |first1=Marcia C. |last1=Linn |first2=Anne C. |last2=Petersen |year=1985 |title=Emergence and Characterization of Sex Differences in Spatial Ability: A Meta-Analysis |journal=Child Development |volume=56 |issue=6 |pages=1479–98 |doi=10.2307/1130467 |jstor=1130467 |pmid=4075870}}</ref> However, 'visual dependence' has been found to be task specific and not a general characteristic of spatial processing that differs between the sexes. Here an alternative hypothesis suggests that heightened visual dependence in females does not generalize to all aspects of spatial processing but is probably attributable to task-specific differences in how male and females brains process multisensory spatial information.<ref>{{cite journal |doi=10.1111/j.1460-9568.2010.07199.x |title=Multisensory determinants of orientation perception: Task-specific sex differences |year=2010 |last1=Barnett-Cowan |first1=M. |last2=Dyde |first2=R. T. |last3=Thompson |first3=C. |last4=Harris |first4=L. R. |journal=European Journal of Neuroscience |volume=31 |issue=10 |pages=1899–907 |pmid=20584195}}</ref>


Performance in mental rotation and similar spatial tasks is affected by gender expectations.<ref name="Fine">{{cite book |url=https://books.google.com/books?id=JbdkAgAAQBAJ&pg=PT96 |title=Delusions of Gender: The Real Science Behind Sex Differences |vauthors=Fine C |publisher=] |year=2005 |isbn=1848313969 |page=96}}</ref> For example, studies show that being told before the test that men typically perform better, or that the task is linked with jobs like aviation engineering typically associated with men versus jobs like fashion design typically associated with women, will negatively affect female performance on spatial rotation and positively influence it when subjects are told the opposite.<ref>{{cite book |doi=10.1037/11546-006 |chapter=Taking Science Seriously: Straight Thinking About Spatial Sex Differences |title=Why aren't more women in science?: Top researchers debate the evidence |year=2007 |last1=Newcombe |first1=Nora S. |pages=69–77 |isbn=978-1-59147-485-2 }}</ref>
Results from studies conducted in the physical environment are not conclusive about sex differences, with various studies on the same task showing no differences. For example, there are studies that show no difference in 'wayfinding'.<ref name="Devlin"/> One study found men more likely to report having a good sense of direction and are more confident about finding their way in a new environment, but evidence does not support men having better map reading skills.<ref name="Montello, Daniel R. 1999">{{cite journal |doi=10.1111/0004-5608.00160 |title=Sex-Related Differences and Similarities in Geographic and Environmental Spatial Abilities |year=1999 |last1=Montello |first1=Daniel R. |author-link1=Daniel R. Montello|last2=Lovelace |first2=Kristin L. |last3=Golledge |first3=Reginald G. |last4=Self |first4=Carole M. |journal=Annals of the Association of American Geographers |volume=89 |issue=3 |pages=515–534}}</ref> Women have been found to use landmarks more often when giving directions and when describing routes.<ref>{{cite journal |doi=10.1016/0001-6918(86)90089-2 |title=Sex differences in spatial abilities: Strategic and experiential correlates |year=1986 |last1=Miller |first1=Leon K. |last2=Santoni |first2=Viana |journal=Acta Psychologica |volume=62 |issue=3 |pages=225–35 |pmid=3766198}}</ref> Additionally, a study concludes that women are better at recalling where objects are located in a physical environment.<ref name="Montello, Daniel R. 1999"/> Women show greater proficiency and reliance on distinctive landmarks for navigation while males rely on an overall mental map.<ref>] (May 13, 2002). "Sex Differences in the Brain: Men and women display patterns of behavioral and cognitive differences that reflect varying hormonal influences on brain development", '']''.</ref><ref>National Geographic - My Brilliant Brain "Make Me a Genius" http://video.google.com/videoplay?docid=-6378985927858479238#</ref>


Playing computer or ] games increases mental rotation ability, especially for females.<ref name="Freiman">{{Cite book|last1=Freiman|first1=Viktor|last2=Tassell|first2=Janet Lynne|title=Creativity and Technology in Mathematics Education|date=2018|publisher=Springer|isbn=978-3-31-972381-5|page=310|url=https://books.google.com/books?id=__1sDwAAQBAJ&pg=PA310}}</ref> Playing action video games in particular benefits spatial abilities in females more than in males, up to a point where sex differences in spatial attention are eliminated.<ref name="Freiman"/> Gender generally has an influence on ]. Action video games such as ]s, adventure games, and sports games are generally preferred by male players, while female players tend to prefer games such as puzzle, card, and ] games.<ref name="Quandt">{{Cite book|last1=Quandt|first1=Thorsten|last2=Kröger|first2=Sonja|title=Multiplayer: The Social Aspects of Digital Gaming|date=2013|publisher=Routledge|isbn=978-1-13-409219-2|page=36|url=https://books.google.com/books?id=zd_eAQAAQBAJ&pg=PA36}}</ref><ref name="Donsbach">{{Cite book|last=Donsbach|first=Wolfgang|title=The Concise Encyclopedia of Communication|date=2015|publisher=John Wiley & Sons|isbn=978-1-11-878923-0|pages=104–105|url=https://books.google.com/books?id=K2ORBgAAQBAJ&pg=PA104}}</ref>
Performance in mental rotation and similar spatial tasks is affected by gender expectations.<ref name="Fine"/><ref name="Caplan">Paula J. Caplan, Gender differences in human cognition, Oxford University Press US, 1997, ISBN 0-19-511291-1, ISBN 978-0-19-511291-7{{page needed|date=June 2013}}</ref> For example, studies show that being told before the test that men typically perform better, or that the task is linked with jobs like aviation engineering typically associated with men versus jobs like fashion design typically associated with women, will negatively affect female performance on spatial rotation and positively influence it when subjects are told the opposite.<ref>Newcombe, N. S. (2007). Taking Science Seriously: Straight thinking about spatial sex differences. In S. Ceci & W. Williams (eds.), ''Why aren't more women in science? Top researchers debate the evidence (pp. 69-77). Washington, DC: American Psychological Association.</ref><ref>{{cite journal |doi=10.1111/j.1471-6402.1994.tb00464.x | volume=18 | title=SPATIAL COGNITION AND GENDER Instructional and Stimulus Influences on Mental Image Rotation Performance | journal=Psychology of Women Quarterly | pages=413–425}}</ref><ref>{{cite journal |doi=10.1016/j.appdev.2006.06.003 |title=Stereotype threat, identity salience, and spatial reasoning |year=2006 |last1=McGlone |first1=Matthew S. |last2=Aronson |first2=Joshua |journal=Journal of Applied Developmental Psychology |volume=27 |issue=5 |pages=486–493 }}</ref><ref>{{cite journal |doi=10.1016/j.psyneuen.2008.09.019 |title=Interactive effects of sex hormones and gender stereotypes on cognitive sex differences—A psychobiosocial approach |year=2009 |last1=Hausmann |first1=Markus |last2=Schoofs |first2=Daniela |last3=Rosenthal |first3=Harriet E.S. |last4=Jordan |first4=Kirsten |journal=Psychoneuroendocrinology |volume=34 |issue=3 |pages=389–401 |pmid=18992993}}</ref> Experiences such as playing ] also increase a person's mental rotation ability.<ref name="Devlin">Devlin, Ann Sloan, Mind and maze: spatial cognition and environmental behavior, Praeger, 2001, ISBN 0-275-96784-0, ISBN 978-0-275-96784-0{{page needed|date=June 2013}}</ref><ref>{{cite journal |doi=10.1007/s11199-008-9498-z |title=Mom, Let Me Play More Computer Games: They Improve My Mental Rotation Skills |year=2008 |last1=Cherney |first1=Isabelle D. |journal=Sex Roles |volume=59 |issue=11–12 |pages=776–86}}</ref> A study from the University of Toronto showed that differences in ability get reduced after playing video games requiring complex mental rotation. The experiment showed that playing such games creates larger gains in spatial cognition in females than males.<ref>{{cite journal |doi=10.1111/j.1467-9280.2007.01990.x |title=Playing an Action Video Game Reduces Gender Differences in Spatial Cognition |year=2007 |last1=Feng |first1=J. |last2=Spence |first2=I. |last3=Pratt |first3=J. |journal=Psychological Science |volume=18 |issue=10 |pages=850–5 |pmid=17894600}}</ref>


The possibility of ] and other ]s as a cause of sex differences in psychology has been a subject of study. Adult women who were exposed to unusually high levels of androgens in the ] due to ] score significantly higher on tests of spatial ability.<ref>{{cite journal |doi=10.1037/0012-1649.22.2.191 |title=Early hormonal influences on cognitive functioning in congenital adrenal hyperplasia |year=1986 |last1=Resnick |first1=Susan M. |last2=Berenbaum |first2=Sheri A. |last3=Gottesman |first3=Irving I. |last4=Bouchard |first4=Thomas J. |journal=Developmental Psychology |volume=22 |issue=2 |pages=191–198}}</ref> Many studies find positive correlations between ] levels in healthy males and measures of spatial ability.<ref>{{cite journal |doi=10.1037/0735-7044.108.2.325 |title=Testosterone influences spatial cognition in older men |year=1994 |last1=Janowsky |first1=Jeri S. |last2=Oviatt |first2=Shelia K. |last3=Orwoll |first3=Eric S. |journal=Behavioral Neuroscience |volume=108 |issue=2 |pages=325–32 |pmid=8037876}}</ref> However, the relationship is complex.<ref>{{cite journal |doi=10.1016/0306-4530(91)90018-O |title=The relationship between testosterone levels and cognitive ability patterns |year=1991 |last1=Gouchie |first1=C |last2=Kimura |first2=D |journal=Psychoneuroendocrinology |volume=16 |issue=4 |pages=323–34 |pmid=1745699}}</ref><ref>{{cite journal |doi=10.1016/S0079-6123(08)64456-8 |chapter=Performance and Intelligence in Hormonally Different Groups |title=Sex Differences in the Brain - the Relation Between Structure and Function |series=Progress in Brain Research |year=1984 |last1=Nyborg |first1=H. |isbn=978-0-444-80532-4 |volume=61 |pages=491–508 |pmid=6396713 |journal=Progress in brain research}}</ref> The possibility of ] and other ]s as a cause of sex differences in psychology has been a subject of study, but results have been mixed. A meta-analysis of women who were exposed to unusually high levels of androgens in the ] due to ] concluded that there is no evidence of enhanced spatial ability among these individuals.<ref name="Collaer">{{cite journal |last1=Collaer |first1=Marcia L. |last2=Hines |first2=Melissa |title=No Evidence for Enhancement of Spatial Ability with Elevated Prenatal Androgen Exposure in Congenital Adrenal Hyperplasia: A Meta-Analysis |journal=Archives of Sexual Behavior |date=February 2020 |volume=49 |issue=2 |pages=395–411 |doi=10.1007/s10508-020-01645-7 |pmid=32052211 |pmc=8784244 |s2cid=211101661 }}</ref> The meta-analysis speculates that average sex differences in some spatial tasks could be partially explained by androgen exposure at a different time of the life span, such as during ], or by the different socialization males and females experience.<ref name="Collaer" /> In addition, a meta-analysis showed that, although female-to-male transgender individuals who received testosterone therapy did improve their spatial abilities, male-to-female transgender individuals who took androgen-suppressants also showed an improvement or no deterioration of spatial skills.<ref>{{cite journal |last1=Karalexi |first1=Maria A. |last2=Georgakis |first2=Marios K. |last3=Dimitriou |first3=Nikolaos G. |last4=Vichos |first4=Theodoros |last5=Katsimpris |first5=Andreas |last6=Petridou |first6=Eleni Th. |last7=Papadopoulos |first7=Fotios C. |title=Gender-affirming hormone treatment and cognitive function in transgender young adults: a systematic review and meta-analysis |journal=Psychoneuroendocrinology |date=September 2020 |volume=119 |pages=104721 |doi=10.1016/j.psyneuen.2020.104721 |pmid=32512250 |s2cid=219123865 |doi-access=free }}</ref>


== Sex differences in academics ==
A study was done to compare the relationship between mental rotation ability and gender difference specifically with the SAT-Math. Cognitive gender differences are apparent and findings of a male advantage in certain mathematical domains have been demonstrated cross-culturally. These gender differences found are largely in geometry and word problems and tend to be in countries with the highest achieving students and with the largest gender gap in experience.<ref name="ReferenceA">{{cite journal |doi=10.1037/0012-1649.31.4.697 |title=The influence of spatial ability on gender differences in mathematics college entrance test scores across diverse samples |year=1995 |last1=Casey |first1=M. Beth |last2=Nuttall |first2=Ronald |last3=Pezaris |first3=Elizabeth |last4=Benbow |first4=Camilla Persson |journal=Developmental Psychology |volume=31 |issue=4 |pages=697–705}}</ref>
<!-- NOTE: Per WP:SCHOLARSHIP, please to stick to secondary or tertiary sourcing for material you add to this article. Avoid primary sources. Avoid single study material unless covered in a secondary or tertiary source.-->
Smaller differences were noted in countries with lower achieving students in mathematics which includes the United States. Moore and Smith state that within the United States, poorly educated female students outperform their male peers, but as the level of education increases, the male advantage in mathematics emerges.<ref name="ReferenceA"/>

A 2014 meta-analysis of sex differences in scholastic achievement published in the journal of '']'' found females outperformed males in teacher-assigned school marks throughout elementary, junior/middle, high school and at both undergraduate and graduate ] level.<ref name=":5">{{Cite journal|url = https://www.apa.org/pubs/journals/releases/bul-a0036620.pdf|title = Gender Differences in Scholastic Achievement: A Meta-Analysis|last = Voyeur|first = Daniel|date = 2014|journal = Psychological Bulletin|doi = 10.1037/a0036620|pmid = 24773502|volume = 140|issue = 4|pages = 1174–1204}}</ref> The meta-analysis done by researchers Daniel Voyer and Susan D. Voyer was from the ] drew from 97 years of 502 effect sizes and 369 samples stemming from the year 1914 to 2011, and found that the magnitude of higher female performance was not affected by year of publication, thereby contradicting recent claims of "]" in school achievement.<ref name=":5" />

A 2015 study by researchers Gijsbert Stoet and ] from the journal of ] reported that girl's overall education achievement is better in 70 percent of all the 47–75 countries that participated in ].<ref name="Stoet 137–151">{{Cite journal|title = Sex differences in academic achievement are not related to political, economic, or social equality|journal = Intelligence|date = 1 January 2015|pages = 137–151|volume = 48|doi = 10.1016/j.intell.2014.11.006|first1 = Gijsbert|last1 = Stoet|first2 = David C.|last2 = Geary| s2cid=143234406 }}</ref> The study consisting of 1.5 million 15-year-olds found higher overall female achievement across reading, mathematics, and science literacy and better performance across 70% of participating countries, including many with considerable gaps in economic and political equality, and they fell behind in only 4% of countries.<ref name="Stoet 137–151" /> Stoet et al. said sex differences in educational achievement are not reliably linked to gender equality.<ref name="Stoet 137–151" />

However, there is some evidence that there is bias in teacher grading against males, although evidence for this is not fully conclusive.<ref name="y770">{{cite web | last1=Liberto | first1=Adriana Di | last2=Casula | first2=Laura | title=Teacher Assessments versus Standardized Tests: Is Acting "Girly" an Advantage? | website=IZA | url=https://www.iza.org/publications/dp/10458/teacher-assessments-versus-standardizedtests-%20is-acting-girly-an-advantage | access-date=2024-09-22}}</ref><ref name="l080">{{cite journal | last=Terrier | first=Camille | title=Boys lag behind: How teachers' gender biases affect student achievement | journal=Economics of Education Review | publisher=Elsevier BV | volume=77 | year=2020 | issn=0272-7757 | doi=10.1016/j.econedurev.2020.101981 | page=101981| url=https://econpapers.repec.org/RePEc:iza:izadps:dp10343 | hdl=10419/149202 | hdl-access=free }}</ref><ref name="r454">{{cite journal | last1=Lievore | first1=Ilaria | last2=Triventi | first2=Moris | title=Do teacher and classroom characteristics affect the way in which girls and boys are graded? | journal=British Journal of Sociology of Education | publisher=Informa UK Limited | volume=44 | issue=1 | date=2022-10-17 | issn=0142-5692 | doi=10.1080/01425692.2022.2122942 | pages=97–122}}</ref><ref name="z851">{{cite journal | last1=Berg | first1=Petter | last2=Palmgren | first2=Ola | last3=Tyrefors | first3=Björn | title=Gender grading bias in junior high school mathematics | journal=Applied Economics Letters | volume=27 | issue=11 | date=2020-06-24 | issn=1350-4851 | doi=10.1080/13504851.2019.1646862 | pages=915–919| url=https://www.ifn.se/wfiles/wp/wp1263.pdf }}</ref> According to a global report performed by the ] of over 60 countries, girls were given higher marks in comparison to boys with the same ability.<ref name="u634">{{cite web | last=Coughlan | first=Sean | title=Teachers 'give higher marks to girls' | website=BBC News | date=2015-03-05 | url=https://www.bbc.com/news/education-31751672 | access-date=2024-10-09}}</ref>

== Historical perspectives ==
<!-- NOTE: Per WP:SCHOLARSHIP, please to stick to secondary or tertiary sourcing for material you add to this article. Avoid primary sources. Avoid single study material unless covered in a secondary or tertiary source.-->


Prior to the 20th century, it was a commonly held view that men were intellectually superior to women.<ref>{{cite book|last1=Lips|first1=Hilary M.|title=Sex & Gender: An Introduction|date=1997|publisher=Mayfield|isbn=978-1559346306|edition=3rd|location=Mountain View, Calif.|page=40}}</ref><ref>{{cite book|last1=Denmark|first1=Florence L.|url=https://archive.org/details/psychologywomenh00denm|title=Psychology of Women: A Handbook of Issues and Theories|last2=Paludi|first2=Michele A.|date=2008|publisher=Praeger|isbn=978-0275991623|edition=2nd|location=Westport, Conn.|pages=–11|url-access=limited}}</ref> Early brain studies comparing mass and volumes between the sexes suggested that women were intellectually inferior because ].<ref name="Fine" /> Writer ] publicly disputed this idea with ], former ].
Spatial ability may be responsible in part for facilitating gender differences in math aptitude. Casey et al. (1995) looked at the relationship of mental rotation ability and the SAT-M among four samples. The four samples were: (1) undergraduates at two liberal arts colleges in the Northeast that were tested on their mental rotation ability in groups of 10-20, (2) a group of mathematically talented preadolescents participating in a summer math and science training in the Midwest which included seventh to ninth graders who were either recruited from a national talent search program or statewide teacher selection program, (3) a high ability group of college bound students who were enrolled in a middle-income suburban high school in the Northeast and elected to take the SAT, and (4) a low ability group of college bound students who were enrolled in a middle-income suburban high school in the Northeast and elected to take the SAT. The data used were SAT math and verbal scores and mental rotation scores. Mental rotation was assessed using the Vandenberg Test of Mental Rotation.<ref name="ReferenceA"/>
Students were asked to match two out of four choices to a standard figure.


In the 19th century, whether men and women had equal intelligence was seen by many as a prerequisite for the granting of ].<ref name="Grandner">Margarete Grandner, Austrian women in the nineteenth and twentieth centuries: cross-disciplinary perspectives, Berghahn Books, 1996, {{ISBN|1-57181-045-5}}, {{ISBN|978-1-57181-045-8}}</ref> ] argued that women were not permitted to realize their full potential, as they were confined to the roles of child-rearing and ].
The study found that that when mental rotation is used as a predictor of Math aptitude for female students, the correlations between mental rotation and SAT-Math scores ranged from 0.35 to 0.38 whereas males showed no consistent pattern. Male correlations ranged from -0.03 to 0.54.<ref name="ReferenceA"/>
However, an interesting finding was that in the three high ability samples, there was a significant gender difference in SAT-Math scores alone. This difference favored males. In the three high ability samples, males scored higher than females in mental rotation ability. Interesting enough, for the verbal aptitude test on SAT, there was a significant difference in verbal ability for the low ability college bound sample favoring girls.<ref name="ReferenceA"/>


During the early 20th century, the scientific consensus shifted to the view that sex plays no role in intelligence.<ref>{{cite journal|last1=Burt|first1=C. L.|last2=Moore|first2=R. C.|year=1912|title=The mental differences between the sexes|journal=Journal of Experimental Pedagogy|volume=1|issue=273–284|pages=355–388}}</ref>
==Dyslexia==


In his 1916 study of children's IQs, psychologist ] concluded that "the intelligence of girls, at least up to 14 years, does not differ materially from that of boys". He did, however, find "rather marked" differences on a minority of tests. For example, he found boys were "decidedly better" in arithmetical reasoning, while girls were "superior" at answering comprehension questions. He also proposed that discrimination, lack of opportunity, women's responsibilities in motherhood, or emotional factors may have accounted for the fact that few women had careers in intellectual fields.<ref name="Terman">{{cite book|last=Terman|first=Lewis M.|url=https://archive.org/details/measurementofint008006mbp|title=The measurement of intelligence: an explanation of and a complete guide for the use of the Stanford revision and extension of the Binet-Simon intelligence scale|publisher=Houghton Mifflin|year=1916|location=Boston|pages=–72|oclc=186102}}</ref><ref name="Dennis">{{cite book|url=https://archive.org/details/historicalreadin0000denn|title=Historical readings in developmental psychology|vauthors=Dennis W|publisher=]|year=1972|isbn=9780390262998|page=|url-access=registration}}</ref>
Dyslexia is a learning disability that impairs a person’s fluency or comprehension accuracy in being able to read.<ref name="National Institute of Neurological Disorders and Stroke">{{cite web|title=Dyslexia Information Page|url=http://www.ninds.nih.gov/disorders/dyslexia/dyslexia.htm}}</ref> The cause of this disability is associated with abnormal brain anatomy and function. Gray matter deficits have been demonstrated in dyslexics using structural magnetic resonance imaging.<ref>{{cite journal |doi=10.1016/S1875-9572(10)60017-4 |title=Brain Imaging Findings in Dyslexia |year=2010 |last1=Sun |first1=Ying-Fang |last2=Lee |first2=Jeun-Shenn |last3=Kirby |first3=Ralph |journal=Pediatrics & Neonatology |volume=51 |issue=2 |pages=89–96}}</ref> This deficit has been found in specific regions within the left hemisphere involved in language.


== See also ==
There is higher prevalence of dyslexia in males than in females.<ref name="Evans et al 2013">{{cite journal |doi=10.1007/s00429-013-0552-4 |title=Sex-specific gray matter volume differences in females with developmental dyslexia |year=2013 |last1=Evans |first1=Tanya M. |last2=Flowers |first2=D. Lynn |last3=Napoliello |first3=Eileen M. |last4=Eden |first4=Guinevere F. |journal=Brain Structure and Function |volume=219 |pages=1041–1054}}</ref> However, different abnormalities are found in female brains as opposed to male brains. In a study that examined gray matter volume in dyslexic females, it was found that there was less gray matter volume in the right precuneus and paracentral lobule/medial frontal gyrus.<ref name="Evans et al 2013" /> In males, there was less gray matter volume in the left inferior parietal cortex.<ref name="Evans et al 2013" /> This study shows that dyslexia in females does not involve the left hemisphere regions involved in language as it does in males. Instead, it affects the sensory and motor cortices such as the motor and premotor cortex and primary visual cortex.<ref name="Evans et al 2013" />
* ]
* ]
* ]
* ]
* ]


==References== ==References==
{{reflist|2}} {{Reflist|2}}


{{Sex differences in humans}} {{Sex differences in humans}}
{{Evolutionary psychology}}


] ]
] ]

Latest revision as of 05:33, 11 November 2024

Area of scientific research
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Sex differences in human intelligence have long been a topic of debate among researchers and scholars. It is now recognized that there are no significant sex differences in average IQ, though particular subtypes of intelligence vary somewhat between sexes.

While some test batteries show slightly greater intelligence in males, others show slightly greater intelligence in females. In particular, studies have shown female subjects performing better on tasks related to verbal ability, and males performing better on tasks related to rotation of objects in space, often categorized as spatial ability.

Some research indicates that male advantages on some cognitive tests are minimized when controlling for socioeconomic factors. It has also been hypothesized that there is slightly higher variability in male scores in certain areas compared to female scores, leading to males' being over-represented at the top and bottom extremes of the distribution, though the evidence for this hypothesis is inconclusive.

IQ research

See also: Intelligence quotient

Background

There is no statistically significant difference between the average IQ scores of men and women. Average differences have been reported, however, on some tests of mathematics and verbal ability in certain contexts. Some studies have suggested that there may be more variability in cognitive ability among males than among females, but others have contradicted this, or presented evidence that differential variability is culturally rather than biologically determined. According to psychologist Diane Halpern, "there are both differences and similarities in the cognitive abilities of women and men, but there is no data-based rationale to support the idea that either is the smarter or superior sex."

Findings

Although most tests show no sex difference, there are some that do. For example, it has been found that female subjects tend to perform better on tests of verbal abilities and processing speed while males tend to perform better on tests of visual-spatial ability and crystallized intelligence. For verbal fluency, females have been specifically found to perform slightly better, on average, in vocabulary and reading comprehension and significantly higher in speech production and essay writing. Males have been specifically found to perform better, on average, in spatial visualization, spatial perception, and mental rotation. None of these findings, however, suggest an advantage for either sex in general intelligence, nor in fluid intelligence.

Most studies find either a very small difference or no sex difference with regard to general intelligence. In 2000, researchers Roberto Colom and Francisco J. Abad conducted a large study of 10,475 adults on five IQ tests taken from the Primary Mental Abilities and found negligible or no significant sex differences. The tests conducted were on vocabulary, spatial rotation, verbal fluency and inductive reasoning.

The literature on sex differences in intelligence has produced inconsistent results due to the type of testing used, and this has resulted in debate among researchers. Garcia (2002) argues that there might be a small insignificant sex difference in intelligence in general (IQ) but this may not necessarily reflect a sex difference in general intelligence or g factor. Although most researchers distinguish between g and IQ, those that argued for greater male intelligence asserted that IQ and g are synonymous (Lynn & Irwing 2004) and so the real division comes from defining IQ in relation to g factor. In 2008, Lynn and Irwing proposed that since working memory ability correlates highest with g factor, researchers would have no choice but to accept greater male intelligence if differences on working memory tasks are found. As a result, a neuroimaging study published by Schmidt (2009) conducted an investigation into this proposal by measuring sex differences on an n-back working memory task. The results found no sex difference in working memory capacity, thus contradicting the position put forward by Lynn and Irwing (2008) and more in line with those arguing for no sex differences in intelligence.

A 2012 review by researchers Richard E. Nisbett, Joshua Aronson, Clancy Blair, William Dickens, James Flynn, Diane F. Halpern and Eric Turkheimer discussed Arthur Jensen's 1998 studies on sex differences in intelligence. Jensen's tests were significantly g-loaded but were not set up to get rid of any sex differences (read differential item functioning). They summarized his conclusions finding "No evidence was found for sex differences in the mean level of g or in the variability of g. Males, on average, excel on some factors; females on others." Jensen's conclusion that no overall sex differences existed for g has been reinforced by researchers who analyzed this issue with a battery of 42 mental ability tests among adults and found no sex difference.

A large analysis by five researchers with a representative sample size of over 15,000 participants found no support for sex differences in IQ, neither among children nor among adults.

A 2022 meta-analysis found that even small sex-based differences in general intelligence were an artifact of older tests, with current test batteries showing no statistically significant difference between the sexes, but that differences in intelligence sub-types such as processing speed (favoring females) and visual-spatial reasoning (favoring males) remained even when controlling for test age.

Variability

Main article: Variability hypothesis

Some studies have identified the degree of IQ variance as a difference between males and females. Some researchers have argued that males tend to show greater variability on many traits, a view which is termed the variability hypothesis; for example, having both highest and lowest scores on tests of cognitive abilities. Other research has been published which contradicts this hypothesis, however, showing either equal variability between the sexes in some cultural contexts or else greater representation of females at the upper extreme of some measures of cognitive ability.

Feingold (1992) and Hedges and Nowell (1995) reported that, despite average sex differences being small and relatively stable over time, test score variances of males were generally larger than those of females. Feingold "found that males were more variable than females on tests of quantitative reasoning, spatial visualisation, spelling, and general knowledge. ... Hedges and Nowell go one step further and demonstrate that, with the exception of performance on tests of reading comprehension, perceptual speed, and associative memory, more males than females were observed among high-scoring individuals."

In regards to variability in mathematics performance, a meta-analysis by Lindberg et al. (2010) found male-to-female variance ratios ranged from 0.88 to 1.34 across studies with an average of 1.07, indicating nearly equivalent male and female variances. The authors note that greater male variability is not ubiquitous, and ratios less than 1.0 have been reported in some national and international data sets. A review by Hyde et al. (2009) also evaluated the topic of greater male variability in mathematics performance. The review found that the gender gap among the highest performers has narrowed over time in the U.S., is not found among some ethnic groups and in some nations, and correlates with several measures of gender inequality. The authors conclude that greater male variability in math performance is largely an artifact of cultural factors as opposed to innate biological sex differences.

Brain and intelligence

See also: Neuroscience of sex differences

Differences in brain physiology between sexes do not necessarily relate to differences in intellect. Although men have larger brains, men and women have equal IQs. For men, the gray matter volume in the frontal and parietal lobes correlates with IQ; for women, the gray matter volume in the frontal lobe and Broca's area (which is used in language processing) correlates with IQ. Women have greater cortical thickness, cortical complexity and cortical surface area (controlling for body size) which compensates for smaller brain size. Meta-analysis and studies have found that brain size explains 6–12% of variance among individual intelligence and cortical thickness explains 5%.

Although a meta-analysis of 148 samples from over 8000 participants reported a weak correlation between brain size and IQ, men and women did not differ in IQ, and the researchers concluded that "it is not warranted to interpret brain size as an isomorphic proxy of human intelligence differences." Brain volume contributes little to IQ test performance. Outside of comparing intelligence levels of the sexes, brain size is only one of numerous factors that influence intelligence, alongside white matter integrity, overall developmental stability, parieto-frontal neuronal networks, neuronal efficiency, and cortical gyrification. Brain structural integrity seems to be more important as a biological basis.

In 2021, Lise Eliot et al found no difference in overall male/female abilities in verbal, spatial or emotion processing.

Mathematics performance

Girl scouts compete in the USS California Science Experience at Naval Surface Warfare Center Corona Division.

Across countries, males have performed better on mathematics tests than females, but there is the possibility male-female difference in math scores is related to gender inequality in social roles. Some psychologists believe that many historical and current sex differences in mathematics performance may be related to boys' higher likelihood of receiving math encouragement than girls. Parents were, and sometimes still are, more likely to consider a son's mathematical achievement as being a natural skill while a daughter's mathematical achievement is more likely to be seen as something she studied hard for. This difference in attitude may discourage girls and women from further involvement in mathematics-related subjects and careers.

In a 2008 study paid for by the National Science Foundation in the United States, researchers found that girls perform as well as boys on standardized math tests. They attributed this to girls now taking as many advanced math courses as boys, unlike in the past.

There is also evidence that boys are over-represented among the very best and very worst performers on measures of mathematical ability and standardized measures of IQ. Some research suggests that differences in mathematics course performance measures favor females. A small performance difference in mathematics on the SAT persists in favor of males, though the gap has shrunk from 40 points (5.0%) in 1975 to 18 points (2.3%) in 2020. However, the SAT is not a representative sample, given that it tests only college-bound students, and more women than men have attended college since the 1990s. Conversely, the international PISA exam provides representative samples. On the 2018 math PISA, there was no statistically significant difference between the performances of girls and boys in 39.5% of the 76 countries that participated. Meanwhile, boys outperformed girls in 32 countries (42.1%), while girls outperformed boys in 14 (18.4%). On average, boys performed 5 points (1%) higher than girls. However, overall, the gender gap in math and science for boys and girls from similar socio-economic backgrounds was not significant.

On the math portion of the 2019 TIMMS, taken at a similar age as the PISA, girls outperformed boys by 3 points on average, although the difference was not statistically significant. A meta-analysis of nearly half a million participants using data from both the TIMMS and the PISA found that differences were negligible, although girls outperfomed boys in some countries and the opposite occurred in others.

A 2008 meta-analysis published in Science using data from over 7 million students found no statistically significant differences between the mathematical capabilities of males and females. A 2011 meta-analysis with 242 studies from 1990 to 2007 involving 1,286,350 people found no overall sex difference of performance in mathematics. The meta-analysis also found that although there were no overall differences, a small sex difference that favored males in complex problem solving was still present in high school. However, the authors note that boys continue to take more physics courses than girls, which train complex solving abilities and may provide stronger training than pure mathematics.

The mathematics GCSE examination results in England have often been inconsistent about which sex performed better. In 2008, 14.7% of females scored an A or above, while only 13.9% of males did the same. But in 2024, only 15.5% of females scored an A or above, while 18% of males did. A 2020 analysis of gender differences in the mathematical abilities of 13 million students in Italy found that males performed better at mathematics and that this difference appeared to increase the richer the Italian regions were, which is also characterized by greater gender equality.

One line of inquiry has focused on the role that stereotype threat might play in mathematics performance differences between male and female test-takers. Systematic reviews and meta-analyses suggest that stereotype threat is implicated in performance differences on some mathematics tests, though the effect appears to vary considerably in different social contexts and for different test conditions.

Reading and verbal skills

Studies have shown a female advantage in reading and verbal skills. On the international PISA reading exam, girls consistently outperform boys across all countries, and all differences are statistically significant. In the most recent PISA exam (2018), girls outperformed boys by almost 30 points. On average in OECD countries, 28% of boys did not obtain a reading proficiency level of 2.

Studies have shown that girls spend more time reading than boys and read more for fun, likely contributing to the gap. Some psychologists believe that many historical and current sex differences in mathematics performance may be related to girls' higher likelihood of receiving reading encouragement than boys. Parents were, and sometimes still are, more likely to consider a daughter's reading achievement as being a natural skill while a son's reading achievement is more likely to be seen as something he studied hard for.

Spatial ability

Examples of figures from mental rotation tests
A man playing a video game at the Japan Media Arts Festival. Spatial abilities can be affected by experiences such as playing action video games, complicating research on sex differences in spatial abilities.

Meta-studies show a male advantage in mental rotation, assessing horizontality and verticality, and a male advantage for most aspects of spatial memory. Women have an advantage for certain components of spatial memory. Whereas men show a selective advantage for fine-grained metric positional reconstruction, where absolute spatial coordinates are emphasized, women show an advantage in spatial location memory, which is the ability to accurately remember relative object positions (where objects are); however, the advantage in spatial location memory is small and inconsistent across studies.

A proposed evolutionary hypothesis is that men and women evolved different mental abilities to adapt to their different roles, including labor-based roles, in society. For example, "ancestral women more often foraged for fruits, vegetables, and roots over large geographic regions." The labor-based role explanation suggests that men may have evolved greater spatial abilities as a result of behaviors such as navigating during a hunt.

Sex differences in mental rotation and judgement of line angles in favor of males have been observed across multiple nations, lending credence to biological origins, though countries with greater gender equality also had greater gaps in these areas, lending credence to possible social influence as well.

Results from studies conducted in the physical environment are not conclusive about sex differences. Various studies on the same task show no differences. There are studies that show no difference in finding one's way between two places.

Performance in mental rotation and similar spatial tasks is affected by gender expectations. For example, studies show that being told before the test that men typically perform better, or that the task is linked with jobs like aviation engineering typically associated with men versus jobs like fashion design typically associated with women, will negatively affect female performance on spatial rotation and positively influence it when subjects are told the opposite.

Playing computer or video games increases mental rotation ability, especially for females. Playing action video games in particular benefits spatial abilities in females more than in males, up to a point where sex differences in spatial attention are eliminated. Gender generally has an influence on preference of game genre. Action video games such as first-person shooters, adventure games, and sports games are generally preferred by male players, while female players tend to prefer games such as puzzle, card, and platform games.

The possibility of testosterone and other androgens as a cause of sex differences in psychology has been a subject of study, but results have been mixed. A meta-analysis of women who were exposed to unusually high levels of androgens in the womb due to congenital adrenal hyperplasia concluded that there is no evidence of enhanced spatial ability among these individuals. The meta-analysis speculates that average sex differences in some spatial tasks could be partially explained by androgen exposure at a different time of the life span, such as during mini-puberty, or by the different socialization males and females experience. In addition, a meta-analysis showed that, although female-to-male transgender individuals who received testosterone therapy did improve their spatial abilities, male-to-female transgender individuals who took androgen-suppressants also showed an improvement or no deterioration of spatial skills.

Sex differences in academics

A 2014 meta-analysis of sex differences in scholastic achievement published in the journal of Psychological Bulletin found females outperformed males in teacher-assigned school marks throughout elementary, junior/middle, high school and at both undergraduate and graduate university level. The meta-analysis done by researchers Daniel Voyer and Susan D. Voyer was from the University of New Brunswick drew from 97 years of 502 effect sizes and 369 samples stemming from the year 1914 to 2011, and found that the magnitude of higher female performance was not affected by year of publication, thereby contradicting recent claims of "boy crisis" in school achievement.

A 2015 study by researchers Gijsbert Stoet and David C. Geary from the journal of Intelligence reported that girl's overall education achievement is better in 70 percent of all the 47–75 countries that participated in PISA. The study consisting of 1.5 million 15-year-olds found higher overall female achievement across reading, mathematics, and science literacy and better performance across 70% of participating countries, including many with considerable gaps in economic and political equality, and they fell behind in only 4% of countries. Stoet et al. said sex differences in educational achievement are not reliably linked to gender equality.

However, there is some evidence that there is bias in teacher grading against males, although evidence for this is not fully conclusive. According to a global report performed by the OECD of over 60 countries, girls were given higher marks in comparison to boys with the same ability.

Historical perspectives

Prior to the 20th century, it was a commonly held view that men were intellectually superior to women. Early brain studies comparing mass and volumes between the sexes suggested that women were intellectually inferior because they have smaller and lighter brains. Writer Helen H. Gardener publicly disputed this idea with William A. Hammond, former Surgeon General of the United States Army.

In the 19th century, whether men and women had equal intelligence was seen by many as a prerequisite for the granting of suffrage. Leta Hollingworth argued that women were not permitted to realize their full potential, as they were confined to the roles of child-rearing and housekeeping.

During the early 20th century, the scientific consensus shifted to the view that sex plays no role in intelligence.

In his 1916 study of children's IQs, psychologist Lewis Terman concluded that "the intelligence of girls, at least up to 14 years, does not differ materially from that of boys". He did, however, find "rather marked" differences on a minority of tests. For example, he found boys were "decidedly better" in arithmetical reasoning, while girls were "superior" at answering comprehension questions. He also proposed that discrimination, lack of opportunity, women's responsibilities in motherhood, or emotional factors may have accounted for the fact that few women had careers in intellectual fields.

See also

References

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  2. ^ Halpern, Diane F. (2001). "Sex Difference Research – Cognitive Abilities". In Worell, Judith (ed.). Encyclopedia of Women and Gender. Elsevier Science. p. 964. ISBN 0080548490.
  3. ^ Hunt, Earl B. (2010). Human Intelligence. Cambridge University Press. pp. 378–379. ISBN 978-1139495110.
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  6. ^ Bosson, Jennifer K.; Buckner, Camille E.; Vandello, Joseph A. (2020). The Psychology of Sex and Gender. New York: SAGE Publications. pp. 250–251. ISBN 978-1544394015.
  7. ^ Sternberg RJ, Kaufman SB (2011). The Cambridge Handbook of Intelligence. Cambridge University Press. p. 877. ISBN 978-1111831004.
  8. Child D (2007). Psychology and the teacher. Continuum. p. 305. ISBN 978-0826487155.
  9. ^ Chrisler JC, McCreary DR (2010). Handbook of Gender Research in Psychology: Volume 1: Gender Research in General and Experimental Psychology. Springer Science & Business Media. p. 302. ISBN 978-1441914651.
  10. ^ Lindberg, Sara M.; Hyde, Janet Shibley; Petersen, Jennifer L.; Linn, Marcia C. (2010). "New trends in gender and mathematics performance: A meta-analysis". Psychological Bulletin. 136 (6): 1123–1135. doi:10.1037/a0021276. PMC 3057475. PMID 21038941.
  11. ^ Hyde, Janet S.; Mertz, Janet E. (2009-06-02). "Gender, culture, and mathematics performance". Proceedings of the National Academy of Sciences of the United States of America. 106 (22): 8801–8807. Bibcode:2009PNAS..106.8801H. doi:10.1073/pnas.0901265106. ISSN 0027-8424. PMC 2689999. PMID 19487665.
  12. ^ Giofrè, D.; Allen, K.; Toffalini, E.; Caviola, S. (22 September 2022). "The Impasse on Gender Differences in Intelligence: a Meta-Analysis on WISC Batteries". Educational Psychology Review. 34 (4): 2543–2568. doi:10.1007/s10648-022-09705-1. hdl:11567/1107935.
  13. ^ Nisbett, Richard E.; Aronson, Joshua; Blair, Clancy; Dickens, William; Flynn, James; Halpern, Diane F.; Turkheimer, Eric (February 2012). "Intelligence: New findings and theoretical developments". American Psychologist. 67 (2): 130–159. doi:10.1037/a0026699. PMID 22233090.
  14. ^ Hyde, Janet Shibley (2006). "Women in Science and Mathematics: Gender Similarities in Abilities and Sociocultural Forces". Biological, Social, and Organizational Components of Success for Women in Academic Science and Engineering: Report of a Workshop. National Academies Press. pp. 127–137. ISBN 978-0-309-10041-0.
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