Sex differences in intelligence
[11] 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.
[12][13] 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.
[3][15] 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.
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.
[16] 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.
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."
[13] 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.
[9] 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.
[6] 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.
[18] 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.
[11] The authors conclude that greater male variability in math performance is largely an artifact of cultural factors as opposed to innate biological sex differences.
[23] 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.
[7] 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.
[24] 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.
[31] 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.
[32] 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.
[33] 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.
[36] One line of inquiry has focused on the role that stereotype threat might play in mathematics performance differences between male and female test-takers.
[45] 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.
"[50] 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.
[51] 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.
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.
[61] 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.
