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Cognitive differences between sexes

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Differences in male and female cognitive abilities are widely established in the current scientific literature.[1][2][3][4][5][6] What is still unclear is how much of these differences is due to biological and genetic differences between sexes, and how much is due to environment and culture.

These studies can lead to controversies very easily, mostly because of the following reasons:

  1. Scientific claims about sex differences in mental abilities are misunderstood as sexism. In truth, scientists do not say that one sex is more intelligent, hence superior, or more stupid, hence inferior, than the other. The studies focus on how, and how much, males and females think differently, and why it is so.
  2. Statistical results are misunderstood as general claims about men and women. If on average a sex performs better/worse in some cognitive task, this does not mean that all the people of such sex are better/worse in that task. Indeed, studies consistently have many exceptions, and the distributions of men's and women's cognitive abilities overlap a lot. So nothing can be said on the intelligence of a single person just by knowing their sex, but statistics can be used to understand general trends on the whole population of men and women.
  3. This topic attracts a lot of pseudoscience, anecdotal evidence, myths, and — in the worst case — dishonest people who try to bend the science in order to support their ideas on men and women.

Additionally, to make things more complicated, the brains of transgender people might be quite peculiar, since tensor imaging studies suggest that they present complex mixtures of masculine, feminine, and demasculinized, defeminized regions.[7]

Brain anatomy[edit]

Average brain weight by sex and age

There are some differences between brain structures between the sexes. The brain, however, is a highly complex structure and is still being studied, so none of these, of course, should translate to higher intelligence or having desirable or undesirable behavior traits (after all, that would be grossly reductionist) nor is there conclusive evidence of the extent these structures can be changed by socialization, cultural upbringing, and other forms of nurture or if nature (genes, sex hormones) drives these developments. Nurture, after all, can have a visible effect on the brain, including the wiring.[8] After all, a social, interactive, stimulating environment is suggested to be beneficial to brain structure.

  • Men have larger brain volume and brain weight com­pared to women on a macroscopic scale.[9][10] The devil is in the details, however, and it shows a more complex picture (this also applies to the other bullet points below): some regions in women's brains are larger than the corresponding regions in men's brains, and the other way around.
  • The planum temporale and Sylvian fissure were found to be larger and longer on average in men than in women. In contrast, the volumes of the superior temporal cortex, Broca's area, the hippocampus, and caudate were significantly larger in women. The midsagittal areas and fiber numbers of the anterior commissure (connecting the temporal lobes) as well as the massa intermedia (connecting the thalami) were found to be larger in women than in men.[11][9]
  • In a study with participants in the 44-77 year age range, men apparently have on average higher raw volume and raw surface areas than women, but at the same time, there was a considerable overlap between the sexes. As well, subregional differences were not at all attributed to brain size. Males also had a larger variance across raw structural measures.[9]
  • Men have a higher percentage of white matter whereas women have a higher percentage of gray matter.[12][13]
  • Women have significantly better connected neural networks compared to men's neural networks, according to a study on people aged 22-35.[14][15] According to a study in youths (8-22 years) male brains are optimized for intrahemispheric communication, while female brains for interhemispheric communication.[16]
  • Male and female brains age in different ways, with males preserving more grey matter in the occipital region and women in bilateral inferior frontal lobes, anterior cingulate gyrus, medial thalamus, and hypothalamus.[17]

Cognitive tasks[edit]

It is widely established in scientific literature that men and women on average perform differently in some cognitive tasks, although there is large overlap in performance between the sexes.[18] Men show higher spatial intelligence, performing better in tests regarding spatial visualization, spatial perception and mental rotation;[19][20][1][21][6] while women have higher performance in verbal abilities, including speech, writing, and reading.[2][3][4][22][5]

It can be argued that these differences in mental abilities are not biological but are the result of culture. That is, society pushes and trains males in spatial reasoning and females in verbal thinking. In this regard, studies with young children are very important, because young children have null or very low cultural conditioning/training.

A 2003 study on a sample of 1,279 children and adolescents, 637 males and 642 females, ranging in age between 5 and 19 years, found that females perform higher on certain verbal tasks and males perform higher on certain spatial tasks.[23] This result is consistent with previous studies regarding male/female mental abilities.[24][25][26][27] However, the age ranges from these studies consist of people that have experienced considerable cultural conditioning.

A 2006 study on a sample of 38 male and female children, 3, 4, and 5 years old, showed that males performed better than females in a spatial task involving the search of a hidden object, and that the male scores increased with age, while the female scores did not.[28] A previous 1999 study on a sample of 288 male and female children, 4 to 7 years old, found a significant male advantage in tests involving mazes and spatial rotations of shapes.[29] However, in both articles it was clear that among the youngest participants (3-4 years old) there were no sex differences yet.

Now the question is: why do these sex differences pop up as children age?

A 2005 study revealed that among boys and girls of low socio-economic status their performance in aerial map tasks and mental rotation tasks showed no significant difference.[30] Reasons for the lack of sex differences among children of low socio-economic status (or rather the existence of them among children of high socio-economic status) were given in the article. The authors suggested that boys and girls in high social-economic status have more access to activities promoting spacial skills (as Legos™, puzzles, video games…), and that boys may engage more in these activities because of biological or environmental reasons, getting better at them.

Another study also explored where this gender difference in spatial cognition among children of higher socio-economic status could come from. Although girls showed equal interest in puzzle play, parents were much more supportive when their sons showed interest in puzzle play, which enhanced the quality of the experience for boys disproportionately.[31] This indicates that there are no biological differences between the sexes regarding their willingness to play games that involve spatial cognition.

IQ[edit]

See the main article on this topic: IQ

Statistical data shows that there is no significative difference between the average IQ scores of men and women.[32][33][34]

Psychology[edit]

Personality traits[edit]

Cross-cultural psychometrics studies have shown differences in the distributions of personality traits between men and women.

On the scales measured by the Big Five personality traits,Wikipedia's W.svg women consistently report higher neuroticism (psychological stress, anger, anxiety, and depression), agreeableness (compassion and cooperativeness), and openness to feelings; while men report higher assertiveness (self-assuredness and confidence without aggressiveness) and openness to ideas.[35][36][37][38][39] These sex differences in personality traits can be detected in early childhood[40][41] and remain fairly constant across adulthood.[42] Moreover, these sex differences in personality traits are larger in prosperous, healthy, and egalitarian cultures in which women have more opportunities equal with men.[35][43] In particular, Asian and African cultures generally show the smallest sex differences, while European and American cultures (in which living standard and gender equality indexes are higher) show the largest differences.[44]

On average the personalty trait of Machiavellianism, characterized by a duplicitous interpersonal style, a cynical disregard for morality, and a focus on self-interest and personal gain, is higher in males than females. In particular, men are over-represented among high Machiavellians, while females are overrepresented among low Machiavellians.[45][46]

Accordingly to 2014 meta-analysis including 355 studies from 13 countries, the personality trait of narcissism is higher in males than females.[47]

Females are on average higher than males in extraversion, anxiety, trust, tender-mindedness (e.g., nurturance), and males are on average more assertive and have higher self-esteem.[48] Women are also more sensitive to punishment and men higher in sensation seeking and risk-taking.[49]

Emotions[edit]

Studies consistently show that women are more prone to express their emotions, both positive and negative, than men.[50][51][52] Such results are not entirely consistent across national and generational boundaries.[53]

Females report experiencing emotion contagion (feeling the same emotions of those around them) more often than males.[54][55]

Women as compared to men report higher fear ratings for all objects and situations related to phobias as enclosed spaces, darkness, flying, heights, spiders, snakes, injections, dentists and/or injuries.[56] Women also report more intense feelings of anger in relation to terrifying situations involving a male.[57] In addition, studies consistently find that women tend to have much higher levels of fear of crime than men.[58][59]

Women cry more intensely than men. The reasons for crying differ between the two genders as well, with men crying more in situations of positive appraisal and loss, and women crying more in situations of conflict. However, this need not be considered a biological difference between the sexes per se. It is theorized that men seek ways to deal with their emotions through instrumentation and organization, as opposed to women who seek to deal with their emotions through personal support groups. Additionally, some of the scientific research has shown that male and female differences in crying is related to the ways in which they are reared. Though doubts have been raised as to this theory, the only recourse when it comes to biology involves resorting to clichés like women's more empathic skills and evopsych nonsense like men crying was dangerous for the tribe and for women. Evidence of women facing more sexual assault than men also has to be admitted into the equation, and cannot be dismissed so easily.[60]

A meta-analysis study by the German Society of Ophthalmology reports that the average woman cries between 30 and 64 times a year, and the average man cries between 6 and 17 times a year. Boys and girls cry around the same rate until age 13. With that being said, the reasons for such weeping are still inconsistent. Biological explanations have proven to be lacking as there have been similarities between pregnant women whose bodies produce more of the hormone prolactin and those lacking said hormone. As well, though it's commonly said that women use their tears to manipulate people, evidence is lacking, as more often than not, apparently people cry alone to themselves rather than in public arenas.[61]

In relationships, men and women tend to be nearly equal when it comes to bargaining tactics across the board on a wide spectrum of areas, such as reason, charm, giving into the other to make them feel better, to actual threats whether they be physical or emotional, but women are more likely to sulk and cry in order to get their way than men.[62]

Also, on average women are better than men in emotional interpretation, such as understanding facial expressions.[63][64]

Psychological studies have found better memory in women than men for emotional events. According to a 2002 MRI study,[65] highly emotional pictures (like pictures of mutilated bodies) are remembered best, and remembered better by women than by men. In particular, men and women activated different neural circuits to encode stimuli effectively into memory even when the analysis was restricted to pictures rated equally arousing by both groups.

A 2014 meta-analysis[66] found that: "it is clear that there are sex differences in empathy from birth, and sex differences appear to be consistent and stable across the lifespan (e.g., Michalska et al., 2013;[67] O’Brien et al., 2013[68]), with females demonstrating higher levels of empathy than males, and children who are higher in empathy early in development continue to be higher in empathy later in development (Eisenberg et al., 1999[69]). This developmental stability suggests that sex differences are unlikely to be caused exclusively by postnatal experiences (e.g., maternal care), but rather reflect some evolutionarily important difference between males and females that is present, at least in some form, from birth, consistent with reports that empathy is moderately heritable (e.g., Baron-Cohen, 2002;[70] Chakrabarti and Baron-Cohen, 2013;[71] Knafo et al., 2008;[72] Rushton, 2004;[73] Zahn-Waxler et al., 1992a,b;[74][75] Zahn-Waxler et al., 2001[76])." Regarding the claim that sex differences in empathy are "stable across the lifespan", it is worth mentioning that the authors cite a study of Michalska[67] which actually says that such differences "widens from childhood to adulthood."

Interests[edit]

Studies show that on average, since from an early age, females are more interested in people-related activities than things-related activities, while for males is the opposite situation.[77][78]

For example, a 2000 study on 102 randomly selected neonates (58 female, 44 male), with a mean age of 36.7 hours, found that males have stronger preferences for looking at a mechanical object than a human face, while for females is the opposite.[77]

Similarly, a 2009 study on 30 infants (17 males and 13 females), with a mean age of 5.76 months, compared the visual preference for a toy truck and a doll, and found that males focus more on the former while female focus more on the latter.[78]

That being said, it doesn't need to be the case that these sex differences are inherently biological. Much ado has been made about faulty science involving infants and their being influenced by their caretakers, as well as reading too much into the perceptions themselves and using that to promote the idea that said causes are biological without accounting for the way infants are reared from the beginning can affect the way they act. For example, in an experiment where caretakers raised a child whose sex was unknown to them, when they were told it was a girl, they encouraged play with dolls and spoke gently, while when told the child was a boy, the caretakers were less verbal and encouraged play with trucks.[79] In addition, parents often raise their children in stereotypical ways relative to their gender. As well, let's accept the explanation for once that there are genetic differences in babies relative to people vs things. The elephant in the room becomes apparent when you consider these were one day old infants. The final nail in the coffin is that it becomes a wide leap to say that, all criticisms notwithstanding and assuming the science is sound, that it is quite a leap to say that boys are necessarily more things-oriented or girls are more people-oriented. As well, it is also quite the assumption to say that the infants in question empathized more with people or things. It could just as well be proposed that the infants in question had longer time to habituate themselves when it comes to perceiving people and things they didn't understand.[80]

In adults, a 2009 meta-analysis using career related interest inventories found that men were more likely to respond to thing related professions, versus women who favored people related professions more. Specifically that men show stronger realistic and investigative interests, and women showed stronger artistic, social, and conventional interests. Sex differences favoring men were also found for more specific measures of engineering, science, and mathematics interests. The study in question used a list of career related interest inventories to gauge these findings. It was also found that the way these career related interest inventories were constructed could affect said interests. It does not mean that these differences were innate.[81]

In addition, another study by the same authors analyzed the disparity in STEM (science, technology, engineering and math) between men and women, and found that interests between genders do indeed seem to explain much of the lopsided representation of men vs women in STEM. There are more men in engineering disciplines and more women in medical and social science disciplines. If the people/things dichotomy is accepted, then there are more opportunities for intervention to facilitate wider representation within the various disciplines, rather than the dead-end answer that these explanations are biological and there is nothing that can be done to fix these problems.[82] Indeed, the same authors in an email to the Verge when their studies were raised in the James Damore fiasco, suggested that women are more different from each other on an individual level, than they differ from the sum population of men.[83]

Also, another study has taken issue with the people vs things dichotomy entirely, suggesting that men and women overall are more balanced and have more in common with each other than they are different.[84]

Mental health disorders[edit]

Although men and women may suffer the same mental health disorders, some illnesses are more common in men than women, and vice versa. This could be because of biological differences between male and female brains, and theories in such regard have been proposed, or it could be because the same mental illness is more diagnosed for a sex than the other, although it occurs with the same frequency.

  • Anorexia is about eight times more common in females.[85]
  • Antisocial personality and substance use disorders are more prevalent in men.[86]
  • Anxiety and mood disorders are more frequent in women.[86]
  • Attention deficit hyperactivity disorder (ADHD) is diagnosed three times more often in males.[87][88] An evolutionary explanation could be that some women are more attracted to males displaying hyperactivity and impulsivity, increasing the frequency of genes that predispose males to ADHD.[89][90] Despite this, the actual amount of ADHD between male and female (as opposed to diagnosed) is believed to be more even given that males are more likely to be identified with ADHD than females due to females' having more subtle signs (thus, females often go undiagnosed and skew the ratio).[91]
  • Dyslexia is up to three times more prevalent in males. This seems to be related to the different gray matter/white matter ratios in men's and women's brains.[92]
  • Schizophrenia is about 1.4 times more prevalent in men than women.[93][94][95]

References[edit]

  1. 1.0 1.1 Maeda, Yukiko; Yoon, So Yoon (2012). "A Meta-Analysis on Gender Differences in Mental Rotation Ability Measured by the Purdue Spatial Visualization Tests: Visualization of Rotations (PSVT:R)". Educational Psychology Review (1): 69-94. https://doi.org/10.1007/s10648-012-9215-x. 
  2. 2.0 2.1 Scheiber; Reynolds; Hajovsky; Kaufman (2015). "Gender differences in achievement in a large, nationally representative sample of children and adolescents". Psychology in the Schools (4): 335-348. https://doi.org/10.1002/pits.21827. 
  3. 3.0 3.1 Reynolds; Scheiber; Hajovsky; Schwartz; Kaufman (2015). "Gender Differences in Academic Achievement: Is Writing an Exception to the Gender Similarities Hypothesis?". The Journal of Genetic Psychology (3-4): 211-234. https://doi.org/10.1080/00221325.2015.1036833. 
  4. 4.0 4.1 Hirnstein; Coloma Andrews; Hausmann (2014). "Gender-Stereotyping and Cognitive Sex Differences in Mixed- and Same-Sex Groups". Archives of Sexual Behavior (8): 1663-1673. https://doi.org/10.1007/s10508-014-0311-5. 
  5. 5.0 5.1 Kwon, Ho-Beom (2010). "Gender difference in speech intelligibility using speech intelligibility tests and acoustic analyses". The Journal of Advanced Prosthodontics (3): 71-76. https://doi.rg/10.4047/jap.2010.2.3.71. 
  6. 6.0 6.1 Foroughi; Wren; Barragan; Mead; Boehm-Davis (2016). "Assessing Mental Rotation Ability in a Virtual Environment with an Oculus Rift". Proceedings of the Human Factors and Ergonomics Society Annual Meeting (1): 1849-1852. https://doi.org/10.1177/1541931215591399. 
  7. Guillamon; Junque; Gómez (2016). "A Review of the Status of Brain Structure Research in Transsexualism". Archives of Sex Behaviour 45: 1615-1648. https://dx.doi.org/10.1007%2Fs10508-016-0768-5. 
  8. De Manzano; Ullén (2018). "Same Genes, Different Brains: Neuroanatomical Differences Between Monozygotic Twins Discordant for Musical Training". Cerebral Cortex (1): 387-394. https://doi.org/10.1093/cercor/bhx299. 
  9. 9.0 9.1 9.2 "Sex Differences in the Adult Human Brain: Evidence from 5216 UK Biobank Participants". Cerebral Cortex (8): 2959–2975. 2018. https://doi.org/10.1093/cercor/bhy109. 
  10. Hartmann; Ramseier; Gudat; Mihatsch; Polasek (1994). "Normal weight of the brain in adults in relation to age, sex, body height and weight". Der Pathologe 15 (3): 165-70. https://www.ncbi.nlm.nih.gov/pubmed/8072950. 
  11. Sex difference in the human brain, their underpinnings and implications. Elsevier. 2010. https://www.elsevier.com/books/sex-differences-in-the-human-brain-their-underpinnings-and-implications/savic-berglund/978-0-444-53630-3. 
  12. Allen; Damasio; Grabowski; Bruss; Zhang (2003). "Sexual dimorphism and asymmetries in the gray-white composition of the human cerebrum". Neuroimage (4): 880-94. https://www.ncbi.nlm.nih.gov/pubmed/12725764. 
  13. Gur; Turetsky; Matsui; Yan; Bilker; Hughett; Gur (1999). "Sex differences in brain gray and white matter in healthy young adults: correlations with cognitive performance". Journal of Neuroscience (10): 4065-72. https://www.ncbi.nlm.nih.gov/pubmed/10234034. 
  14. Szalkai, Balazs; Varga, Bálint; Grolmusz, Vince (2015). "Graph Theoretical Analysis Reveals: Women’s Brains Are Better Connected than Men's". PLoS ONE (7). https://dx.doi.org/10.1371/journal.pone.0130045. 
  15. Szalkai, Balázs; Varga, Bálint; Grolmusz, Vince (2017). "Brain size bias compensated graph-theoretical parameters are also better in women's structural connectomes". Brain Imaging and Behavior. PMID 28447246. https://dx.doi.org/10.1007/s11682-017-9720-0. 
  16. Ingalhalikar; Smith; Parker, et al (2014). "Sex differences in the structural connectome of the human brain". Proceedings of the National Academy of Sciences of the United States of America (2): 823-8. https://dx.doi.org/10.1073/pnas.1316909110. 
  17. Gender and age differences in normal adult human brain: voxel-based morphometric study, Takahashi R et al, Hum Brain Mapp. 2011 Jul;32(7):1050-8. doi: 10.1002/hbm.21088. Epub 2010 Jul 6.
  18. Gender-Stereotyping and Cognitive Sex Differences in Mixed- and Same-Sex Groups, Marco Hirnstein, Lisa Coloma Andrews, and Markus Hausmann, Arch Sex Behav. 2014; 43(8): 1663–1673.
  19. Linn, Marcia C.; Petersen, Anne C. (1985). "Emergence and Characterization of Sex Differences in Spatial Ability: A Meta-Analysis". Child Development (6): 1479-1498. https://doi.org/10.1111/j.1467-8624.1985.tb00213.x. 
  20. Maclntyre, Tadhg (2012). "Gender differences in cognition: A minefield of research issues". The Irish Journal of Psychology (4): 386-396. https://doi.org/10.1080/03033910.1997.1010558158. 
  21. Donnon, Tyrone; DesCôteaux, Jean-Gaston; Violato, Claudio (2005). "Impact of cognitive imaging and sex differences on the development of laparoscopic suturing skills". Canadian Journal of Surgery (5): 387-393. 
  22. Olson; Hulslander; Christopher; Keenan; Wadsworth; Willcutt; Pennington; DeFries (2013). "Genetic and Environmental Influences on Writing and their Relations to Language and Reading". Annals of Dyslexia (1): 25-43. https://doi.org/10.1007/s11881-011-0055-z. 
  23. Lowe, Patricia; Mayfield, Joan W.; Reynolds, Cecil R. (2003). "Gender differences in memory test performance among children and adolescents". Archives of Clinical Neuropsychology (8): 865-878. https://doi.org/10.1016/S0887-6177(02)00162-2. 
  24. Maccoby and Jacklin (1974). The psychology of sex differences. Stanford, CA: Stanford University Press. 
  25. Born; Bleichrodt; Van Der Flier (1987). "Cross-cultural comparison of sex-related differences on intelligence tests". Journal of Cross-Cultural Psychology (3): 283-314. https://doi.org/10.1177/0022002187018003002. 
  26. Mann, Virginia A.; Sasanuma, Sumiko; Sakuma, Naoko; Masaki, Shinobu (1990). "Sex differences in cognitive abilities: A cross-cultural perspective". Neuropsychologia (10): 1063-1077. https://doi.org/10.1016%2F0028-3932%2890%2990141-A. 
  27. Grant and Adams (1996). Neuropsychological assessment of neuropsychiatric disorders. New York: Oxford Press. 
  28. Spetch; Parent (2006). "Age and sex differences in children’s spatial search strategies". Psychonomic Bulletin & Review (5): 807-812. https://doi.org/10.3758/BF03194001. 
  29. Levine; Huttenlocher; Taylor; Langrock (1999). "Early sex differences in spatial skill". Developmental Psychology (4): 940-9. https://doi.org/10.1037/0012-1649.35.4.940. 
  30. Levine; Vasilyeva; Lourenco; Newcombe; Huttenlocher (2005). "Socioeconomic Status Modifies the Sex Difference in Spatial Skill". Psychological Science. https://doi.org/10.1111/j.1467-9280.2005.01623.x.  Link to PDF
  31. Levine; Ratliff; Huttenlocher; Cannon (2012). "Early Puzzle Play: A Predictor of Preschoolers' Spatial Transformation Skill". Developmental Psychology 48 (2): 530-542. https://doi.org/10.1037/a0025913.  Link to PDF
  32. Colom; García; Juan-Espinosa; Abad (2002). "Null sex differences in general intelligence: Evidence from the WAIS-III". The Spanish journal of psychology (1): 29-35. https://doi.org/10.1017/s1138741600005801. 
  33. Hedges; Nowell (1995). "Sex differences in mental test scores, variability, and numbers of high-scoring individuals". Science (5220): 41-5. https://doi.org/10.1126/science.7604277. 
  34. Neisser; Boodoo; Bouchard; Boykin; Brody; Ceci; Halpern; Loehlin et al. (1996). "Intelligence: Knowns and Unknowns". American Psychologist (2): 77-101. https://doi.org/10.1037/0003-066X.51.2.77. 
  35. 35.0 35.1 Costa; Terracciano; McCrae (2001). "Gender differences in personality traits across cultures: robust and surprising findings". Journal of Personality and Social Psychology 81 (2): 322-331. https://doi.org/10.1037/0022-3514.81.2.322. 
  36. Vianello, Michelangelo; Schnabel, Konrad; Sriram; Nosek, Brian (2013). "Gender differences in implicit and explicit personality traits". Personality and Individual Differences 55 (8): 994-999. https://doi.org/10.1016/j.paid.2013.08.008. 
  37. Lynn, Richard; Martin, Terence (1997). "Gender Differences in Extraversion, Neuroticism, and Psychoticism in 37 Nations". The Journal of Social Psychology 137 (3). https://doi.org/10.1080/00224549709595447. 
  38. Weisberg, Yanna J.; DeYoung, Colin G.; Hirsh3, Jacob (2011). "Gender Differences in Personality across the Ten Aspects of the Big Five". Frontiers in Psychology 178 (2). https://dx.doi.org/10.3389%2Ffpsyg.2011.00178. 
  39. Chapman, Benjamin; Duberstein, Paul R.; Sörensen, Slivia; Lyness, Jeffrey (2007). "Gender Differences in Five Factor Model Personality Traits in an Elderly Cohort: Extension of Robust and Surprising Findings to an Older Generation". Personality and Individual Differences 43 (06): 1594-1603. https://dx.doi.org/10.1016%2Fj.paid.2007.04.028. 
  40. Else-Quest; Hyde; Goldsmith; Van Hulle (2006). "Gender differences in temperament: A meta-analysis". Psychological Bulletin 132: 33-72. https://doi.org/10.1037/0033-2909.132.1.33. 
  41. Wilgenbusch; Merrell (1999). "Gender differences in self-concept among children and adolescents: A meta-analysis of multidimensional studies". School Psychology Quarterly 14: 101-120. http://psycnet.apa.org/doi/10.1037/h0089000. 
  42. Feingold (1994). "Gender differences in personality: a meta-analysis". Psychological Bulletin 116: 429-456. https://www.ncbi.nlm.nih.gov/pubmed/7809307. 
  43. McCrae (2002). "NEO-PI-R data from 36 cultures: Further intercultural comparisons". International and cultural psychology series. The Five-Factor model of personality across cultures: 105-125. http://psycnet.apa.org/doi/10.1007/978-1-4615-0763-5_6. 
  44. McCrae; Terracciano (2005). "Universal features of personality traits from the observer's perspective: data from 50 cultures". ournal of Personality and Social Psychology 88: 547-561. https://doi.org/10.1037/0022-3514.88.3.547. 
  45. Christie, R. & Geis, F. (1970) "Studies in Machiavellianism". NY: Academic Press.
  46. Gunnthorsdottir; McCabe; VernonSmith (2002). "Using the Machiavellianism instrument to predict trustworthiness in a bargaining game". Journal of Economic Psychology (1): 49-66. https://doi.org/10.1016/S0167-4870(01)00067-8. 
  47. Grijalva; Newman; Tay; Donnellan; Harms; Robins; Yan. "Gender differences in narcissism: A meta-analytic review.". Psychological Bulletin 141 (2): 261-310. https://doi.org/10.1037/a0038231. 
  48. Feingold (1994-11-01). "Gender differences in personality: a meta-analysis". Psychological Bulletin 116 (3): 429-456. ISSN 0033-2909. PMID 7809307. https://doi.org/10.1037/0033-2909.116.3.429. 
  49. Cross; Copping; Campbell (2011). "Sex differences in impulsivity: a meta-analysis". Psychological Bulletin 137 (1): 97-130. https://doi.org/10.1037/a0021591. 
  50. Chaplin; Hong; Bergquist; Sinha (2008). "Gender differences in response to emotional stress: an assessment across subjective, behavioral, and physiological domains and relations to alcohol craving". Alcholism, clinical and experimental research 32 (7): 1242-50. https://doi.org/10.1111/j.1530-0277.2008.00679.x. 
  51. Kring; Gordon (1998). "Sex differences in emotion: expression, experience, and physiology". Journal of Personality and Social Psychology 74 (3): 686-703. https://www.ncbi.nlm.nih.gov/pubmed/9523412. 
  52. Yaling Deng; Lei Chang; Meng Yang; Meng Huo; Renlai Zhou1 (2016). "Gender Differences in Emotional Response: Inconsistency between Experience and Expressivity". PLoS One 11 (6). https://dx.doi.org/10.1371%2Fjournal.pone.0158666. 
  53. Gong; Wong; Wang (2018). "Are Gender Differences in Emotion Culturally Universal? Comparison of Emotional Intensity Between Chinese and German Samples". Journal of Cross-Cultural Psychology. http://journals.sagepub.com/doi/abs/10.1177/0022022118768434. 
  54. Kevrekidis; Skapinakis; Damigos; Mavreas (2008). "Adaptation of the Emotional Contagion Scale (ECS) and gender differences within the Greek cultural context". Annals of General Psychiatrics. https://doi.org/10.1186/1744-859X-7-14. 
  55. Magen; Konasewich (2011). "Women Support Providers Are More Susceptible Than Men to Emotional Contagion Following Brief Supportive Interactions". Psychology of Women Quarterly 35 (4): 611-616. https://doi.org/10.1177%2F0361684311423912. 
  56. Fredrikson; Annas; Fischer; Wik (1996). "Gender and age differences in the prevalence of specific fears and phobias". Behaviour research and therapy 34 (1): 33-9. https://www.ncbi.nlm.nih.gov/pubmed/8561762. 
  57. Brody; Lovas; Hay (1995). "Gender differences in anger and fear as a function of situational context". Sex Roles 32: 47-78. https://doi.org/10.1007/BF01544757. 
  58. Stanko (1995). "Women, Crime, and Fear". The Annals of the American Academy of Political and Social Science 539: 46-58. https://doi.org/10.1177/0002716295539001004. 
  59. Britton, Dana (2011). The Gender of Crime. Rowman & Littlefield. pp. 90. 
  60. Agneta H. Fischer (2000). Gender and Emotion: Social Psychological Perspectives. Part of Studies in Emotion and Social Interaction.  pp. 145-151
  61. "Frauen und Männer weinen anders [German: Woman and Men Cry Differently]". Deutsche Ophtalmologische Gesellschaft. 2009. 
  62. Buss (1992). "Manipulation in close relationships: Five personality factors in interactional context". Journal of Personality 60: 477-499. https://www.ncbi.nlm.nih.gov/pubmed/1635051. 
  63. Kirkland; Peterson; Baker; Miller; Pulos (2013). "Meta-analysis reveals adult female superiority in "Reading the Mind in the Eyes" Test". North American Journal of Psychology 15 (1): 121-146. http://psycnet.apa.org/record/2013-09240-009. 
  64. Kret; De Gelder (2012). "A review on sex differences in processing emotional signals". Neuropsychologia 50 (7): 1211-1221. https://doi.org/10.1016/j.neuropsychologia.2011.12.022. 
  65. Canli; Desmond; Zhao; Gabrieli (2002). "Sex differences in the neural basis of emotional memories". Proceedings of the National Academy of Sciences of the United States of America 99 (16): 10789-10794. https://doi.org/10.1073/pnas.162356599. 
  66. Christov-Moorea; Simpson; Coudé; Grigaityte; Iacoboni; Ferrari (2014). "Empathy: Gender effects in brain and behavior". Neuroscience & Biobehavioral Reviews 46: 604-627. https://doi.org/10.1016/j.neubiorev.2014.09.001.  Open Access
  67. 67.0 67.1 Michalska; Kinzler; Decety (2013). "Age-related sex differences in explicit measures of empathy do not predict brain responses across childhood and adolescence". Developmental Cognitive Neuroscience (3): 22-32. https://doi.org/10.1016/j.dcn.2012.08.001. 
  68. O'Brien; Konrath; Grühn; Hagen (2013). "Empathic concern and perspective taking: linear and quadratic effects of age across the adult life span". The journals of gerontology. Series B, Psychological sciences and social sciences 68 (2): 168-75. https://doi.org/10.1093/geronb/gbs055. 
  69. Eisenberg; Guthrie; Murphy; Shepard; Cumberland; Carlo (1999). "Consistency and development of prosocial dispositions: a longitudinal study". Child Development 70 (6): 1360-72. https://www.ncbi.nlm.nih.gov/pubmed/10621961. 
  70. "The extreme male brain theory of autism.". Trends in Cognitive Sciences 6 (6): 248-254. 2002. https://www.ncbi.nlm.nih.gov/pubmed/12039606. 
  71. Chakrabarti; Baron-Cohen (2013). Understanding the genetics of empathy and the autistic spectrum. In: Baron-Cohen S, Tager-Flusberg H, Lombardo MV, editors. Understanding Other Minds: Perspectives from developmental social neuroscience.  pp. 326-342
  72. Knafo; Zahn-Waxler; Van Hulle; Robinson; Rhee (2008). "The developmental origins of a disposition toward empathy: Genetic and environmental contributions". Emotion (Washington D.C.) 8 (6): 737-52. https://doi.org/10.1037/a0014179. 
  73. Rushton (2004). "Genetic and environmental contributions to pro-social attitudes: a twin study of social responsibility". Proceedings. Biological Sciences. 271 (1557): 2583-5. https://www.ncbi.nlm.nih.gov/pubmed/15615684/. 
  74. Zahn-Waxler; Radke-Yarrow; Wagner; Chapman (1992). "Development of concern for others". Developmental Psychology 28 (1): 126-136. http://dx.doi.org/10.1037/0012-1649.28.1.126. 
  75. Zahn-Waxler; Carolyn; Robinson; JoAnn; Emde (1992). "The development of empathy in twins". Developmental Psychology 28 (6): 1038-1047. http://dx.doi.org/10.1037/0012-1649.28.6.1038. 
  76. Zahn-Waxler; Schiro; Robinson; Emde; Schmitz (2001). Empathy and prosocial patterns in young MZ and DZ twins. In: Emde RN, Hewitt JK, editors. Infancy to Early Childhood: Genetic and Environmental Influences on Developmental Change. Oxford University Press; New York, NY.  pp. 141-162
  77. 77.0 77.1 Connellan; Baron-Cohen; Wheelwright; Batki; Ahluwalia (2000). "Sex differences in human neonatal social perception". Infant Behavior & Development: 113-118. https://doi.org/10.1016/S0163-6383(00)00032-1.  Links to PDF: 1, 2, 3
  78. 78.0 78.1 Alexander; Wilcox; Woods (2009). "Sex Differences in Infants’ Visual Interest in Toys". Archives of Sexual Behaviour: 427-433. https://doi.org/10.1007/s10508-008-9430-1.  Links to PDF: 1, 2, 3
  79. Will; Self; Datan (1976). "Maternal behavior and perceived sex of infant". The American Journal of Orthopsychiatry 46 (1): 135-9. https://www.ncbi.nlm.nih.gov/pubmed/1247092. 
  80. Rogers (2003). "Extreme Problems with Essential Differences: The Essential Difference: The Truth about the Male & Female Brain". Cerebrum: Timely and provocative articles on neuroscience. http://www.dana.org/Cerebrum/2003/Extreme_Problems_with_Essential_Differences. 
  81. Su; Rounds; Armstrong (2009). "Men and Things, Women and People: A Meta-Analysis of Sex Differences in Interests". Psychological Bulletin 135 (6): 859-884. https://doi.org/10.1037/a0017364.  Links to PDF: 1, 2, 3
  82. Su; Rounds (2015). "All STEM fields are not created equal: People and things interests explain gender disparities across STEM fields". Frontiers in Psychology 25. https://doi.org/10.3389/fpsyg.2015.00189. 
  83. Sarah Jeong and Rachel Becker (2017). "Science doesn’t explain tech’s diversity problem — history does". The Verge. https://www.theverge.com/2017/8/16/16153740/tech-diversity-problem-science-history-explainer-inequality. 
  84. Spelke (2005). "Sex differences in intrinsic aptitude for mathematics and science?: a critical review". The American Psychiologist 60 (9): 950-8. https://doi.org/10.1037/0003-066X.60.9.950. 
  85. Hoek, HW (2006). "Incidence, prevalence and mortality of anorexia nervosa and other eating disorders". Current Opinion in Psychiatry (4): 389-94. https://doi.org/10.1097/01.yco.0000228759.95237.78. 
  86. 86.0 86.1 Eaton, NR; Keyes, KM; Krueger et al, RF (2012). "An invariant dimensional liability model of gender differences in mental disorder prevalence: evidence from a national sample". Journal of Abnormal Psychology (1): 282-8. https://doi.org/10.1037/a0024780. 
  87. Emond; Joyal; Poissant (2009). "Neuroanatomie structurelle et fonctionnelle du trouble déficitaire d’attention avec ou sans hyperactivité (TDAH)". Encephale (2): 107-14. https://doi.org/10.1016/j.encep.2008.01.005. 
  88. Singh (2008). "Beyond polemics: Science and ethics of ADHD". Nature Reviews Neuroscience (12): 957-64. https://doi.org/10.1038/nrn2514. 
  89. Glover (2011). "Annual Research Review: Prenatal stress and the origins of psychopathology: an evolutionary perspective". Journal of Children Psychology and Psychiatry (4): 356-67. https://doi.org/10.1111/j.1469-7610.2011.02371.x. 
  90. Williams; Taylor (2006). "The evolution of hyperactivity, impulsivity and cognitive diversity". Journal of The Royal Society Interface (8): 399-413. https://doi.org/10.1098/rsif.2005.0102. 
  91. Sigler, E. ADHD Looks Different In Women. Here’s How — and Why. ADDitude. Retrieved September 29, 2018.
  92. Evans, Tanya M.; Flowers, D. Lynn; Napoliello, Eileen M.; Eden, Guinevere F. (2013). "Sex-specific gray matter volume differences in females with developmental dyslexia". Brain Structure and Function: 1041-1054. https://dx.doi.org/10.1007/s00429-013-0552-4. 
  93. McGrath; Saha; Chant, David; Welham (2008). "Schizophrenia: A Concise Overview of Incidence, Prevalence, and Mortality". Epidemiologic Reviews 30: 67–76. https://doi.org/10.1093/epirev/mxn001. 
  94. Aleman; Kahn; Selten (2003). "Sex differences in the risk of schizophrenia: evidence from meta-analysis". Archives of General Psychiatry 60 (6): 565–71. http://doi.org/10.1001/archpsyc.60.6.565. 
  95. Abel; Drake; Goldstein, Jill (2010). "Sex differences in schizophrenia". International Review of Psychiatry (22(5)): 417–428. http://web.a.ebscohost.com.erl.lib.byu.edu/ehost/pdfviewer/pdfviewer?sid=c8115b8c-f775-4ea4-aa5f-f342423245fd%40sessionmgr4010&vid=3&hid=4201.