Sex differences in psychology
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The field of psychology has identified numerous differences between the mental functions and behaviors of men and women. These differences are created by a complex interplay of biological, developmental, and cultural processes. An important objective of sex differences research is to identify which psychological traits are manifestations of sexually dimorphic (different) psychological adaptations. Sexually dimorphic adaptations (such as height or physical aggressiveness) are the products of the evolutionary process of sexual selection. Research to determine if a trait is sexually dimorphic or monomorphic is often conducted by biologists, neuroscientists, and evolutionary psychologists. However, there is a conflicting theoretical paradigm, called social constructionism, which suggests that male/female brains are sexually monomorphic (the same), and that gender differences are mostly due to differences in socialization (see: social construction of gender difference). Scholarship based on this theoretical paradigm is often conducted by social psychologists, sociologists, and cultural anthropologists. For further differentiation of the terms "sex" and "gender" see: sex and gender distinction.
Numerous factors may influence the development of sex differences including genetics and epigenetics, differences in brain structure and function; hormones, or differences in psychological traits such as emotion, motivation, cognition, and sexuality. Differences in socialization of males and females may decrease or increase the magnitude of sex differences. Fundamental sex differences may manifest as cultural phenomena. Since all behavior is phenotypical (occurs as a result of complex interactions between nature and nurture) researchers are especially interested in investigating how biology and environment interact to produce differences between the sexes.
- 1 Introduction
- 2 History
- 3 Biology
- 4 Psychological traits
- 5 Culture
- 6 Controversies
- 7 See also
- 8 References
- 9 Bibliography
The terms "sex differences" and "gender differences" are sometimes used interchangeably, or, more often they are incorrectly used to refer to differences in male and female behaviors that are presumed to be due to either biological causes ("sex differences") or environmental/cultural causes ("gender differences"). However, most scientists agree that the nature vs. nurture debate is sterile and misleading—all behaviors are a complex interaction of both biological and environmental/cultural causality. To avoid confusion, the term "sex differences" is often used by scientists to refer to sexually dimorphic adaptations (such as height)."
Adaptations are organismic traits that evolved by means of natural or sexual selection to help an organism survive or reproduce in ancestral environments (see inclusive fitness). Not all traits are adaptations -- some traits are byproducts of adaptations and some traits are due to random variation. For example, the umbilical cord is an adaptation. But the belly button is not -- it is a functionless byproduct of an adaptation (the remnants of the umbilical cord). Also, the convex or concave belly button shape is also not a adaptation but it is likely due to functionless random variation. Traits that are adaptations can be either sexually dimorphic (different between the sexes -- e.g., height) or sexually monomorphic (the same between the sexes, e.g., the set of different blood types). Sexually dimorphic adaptations are products of the evolutionary process of sexual selection. Sexual selection is the evolutionary process that produces sexually dimorphic adaptations that help each sex maximize their reproductive success (e.g., the peacock's tail and the peahen's preference for peacocks with large tails).
Psychological sex differences refer to underlying emotional, motivational or cognitive adaptations that are hypothesized to be sexually dimorphic, and, to their behavioral manifestations. For example, greater male tendencies toward violence, and the female use of "motherese" (sing-song inflections of the voice when speaking to infants), are hypothesized to be sexually dimorphic psychological adaptations.
In his 1859 book On the Origin of Species Charles Darwin hypothesized that sexually dimorphic traits were an evolved product of the process he termed sexual selection. Darwin also proposed that, like physical traits, psychological traits evolve:
In the distant future I see open fields for far more important researches. Psychology will be based on a new foundation, that of the necessary acquirement of each mental power and capacity by gradation.—Charles Darwin, The Origin of Species, 1859, p. 449.
He explored the evolution of sexually dimorphic psychological traits in two of his later books, The Descent of Man, and Selection in Relation to Sex in 1871 and The Expression of the Emotions in Man and Animals in 1872. The The Descent of Man and Selection in Relation to Sex includes 70 pages on sexual selection in human evolution, and 500 pages on sexual selection in other animals.
In 1972 Robert Trivers published an influential paper on sex differences that is now referred to as parental investment theory. The size differences of gametes (anisogamy) is the fundamental, defining difference between males (small gametes—sperm) and females (large gametes—ova). Trivers noted that anisogamy typically results in different levels of parental investment between the sexes, with females initially investing more. Trivers proposed that this difference in parental investment leads to the sexual selection of different reproductive strategies between the sexes and to sexual conflict. For example, he suggested that the sex that invests less in offspring will generally compete for access to the higher-investing sex to increase their inclusive fitness (also see Bateman's principle). Trivers posited that differential parental investment led to the evolution sexual dimorphisms in mate choice, intra- and inter- sexual reproductive competition, and courtship displays. In mammals, including humans, females make a much larger parental investment than males (i.e. gestation followed by childbirth and lactation). Parental investment theory is a branch of life history theory.
Buss and Schmitt's (1993) Sexual Strategies Theory proposed that, due to differential parental investment, humans have evolved sexually dimorphic adaptations related to "sexual accessibility, fertility assessment, commitment seeking and avoidance, immediate and enduring resource procurement, paternity certainty, assessment of mate value, and parental investment." Their Strategic Interference Theory suggested that conflict between the sexes occurs when the preferred reproductive strategies of one sex interfere with those of the other sex, resulting in the activation of emotional responses such as anger or jealousy.
Sex linkage occurs when phenotypic expression of a trait is related to the chromosomal sex of the individual. This mode of inheritance is in contrast to when both sexes have the same probability of inheritance of the trait. This in turn is due to the expression of one or several alleles present on a sex chromosome as opposed to on a autosomal (non-sex) chromosome.
Sex-linked characteristics, which are controlled by genes on sex chromosomes, can be differentiated from "sex influenced" and "sex-limited" traits. "Sex-influenced" (or sex-conditioned) traits are phenotypes affected by whether they appear in a male or female body. Even in a homozygous dominant or recessive female the condition may not be expressed fully. Example: baldness in humans. "Sex-limited" traits are characteristics only expressed in one sex. They may be caused by genes on either autosomal or sex chromosomes.
Sex-linked genes have been found to differentially affect the brains of males and females. A 2013 study found that "sex differences in gene expression and splicing are widespread in adult human brain, being detectable in all major brain regions and involving 2.5% of all expressed genes."
Epigenetic effects have also been found to cause sex differences in the brain.
Brain structure and function
Studies have found many similarities but also differences in brain structure, neurotransmitters, and function. However, some argue that innate differences in the neurobiology of men and women have not been conclusively identified. The relationship between sex differences in the brain and human behavior is a subject of controversy in psychology and society at large.
A 2004 review in Nature Reviews Neuroscience stated that the brain's sexual dimorphism is probably determined by genes on the sex chromosomes. They likely do so by genes in cells in the gonads causing the gonads to produce sex hormones that travel to the brain which affect brain cells and also by genes in brain cells directly affecting these brain cells. In the human brain, a difference between sexes has been observed in regarding the PCDH11X/Y gene pair which is unique to Homo sapiens.
In adults, men's brains are an average of 11–12% heavier than women's brains. However, due to relative difference in body size some researchers propose that the brain-to-body mass ratio does not differ between the sexes. A 1992 study of 6,325 Army personnel found that men's brains had an average volume of 1442 cm3, while the women averaged 1332 cm3, and differences were shown to be smaller but persisting after being adjusted for body size measured as body height or body surface, such that women averaged 100g less brain mass than men of equal size.
Though statistically there are sex differences in white matter and gray matter percentage, this ratio is directly related to brain size, and some argue these sex differences in gray and white matter percentage are caused by the average size difference between men and women. Others argue that these differences remain after controlling for brain volume.
In the cerebral cortex it has been observed that there is greater intra-lobe neural communication in male brains and greater inter-lobe (between the left and right hemispheres of the cerebral cortex) neural communication in female brains.
Testosterone appears to be a major contributing factor to sexual motivation in male primates, including humans. The elimination of testosterone in adulthood has been shown to reduce sexual motivation in both male humans and male primates. Male humans who had their testicular function suppressed with a GnRH anatagonist displayed decreases in sexual desire and masturbation two weeks following the procedure. It is also suggested that levels of testosterone in men are related to the type of relationship in which they are involved. Men involved in polyamorous relationships display higher levels of testosterone than men involved in either a single partner relationship or single men.
Females at different stages of their menstrual cycle have been shown to display differences in sexual attraction. Non-pill using heterosexual females who are ovulating (high levels of estrogens) have a preference for the scent of males with low levels of fluctuating asymmetry. Ovulating heterosexual females also display preferences toward masculine faces and report greater sexual attraction to males other than their current partner. From an evolutionary perspective, increases in estrogens during fertile periods in females may direct sexual motivation toward males with preferential genes (the good genes hypothesis).
Development of gender identity
Individuals who are sex reassigned at birth offer an opportunity to see what happens when a child who is genetically one sex is raised as the other. The largest study of such individuals was conducted by Reiner & Gearhart on 14 children born with cloacal exstrophy and reassigned female at birth. Upon follow-up between the ages of 5 to 12, 8 of them identified as boys, and all of the subjects had at least moderately male-typical attitudes and interests, however these tests were not double blind as the parents (and often the subjects) knew the biological sex of children they were raising. The procedure of sex reassignment and vaginoplasty on intersex children assigned to be females also changes their experiences in ways not analogous to typically developed females, including vaginal dilatation by parents on toddlers (routine widening of the vagina through insertion of a device), and testing of clitoral scar tissue for sensation by doctors.
Girls with congenital adrenal hyperplasia and thus exposed to high androgen level during pregnancy play more with boy toys and less with girl toys. The same difference in play behavior was observed in guenon and rhesus macaque. A study with 112 boys and 100 girls found that the difference in play behavior was correlated with fetal testosterone. Together these studies suggest that fetal testosterone influences play behavior in primates. In human, this effect of testosterone on typical - and atypical - play behavior may influence gender development.
One study showed that at birth girls gaze longer at a face, whereas suspended mechanical mobiles, rather than a face, keep boys' attention for longer, though this study has been criticized as having methodological flaws.
The Sexual Strategies Theory by David Buss and David P. Schmitt is a comprehensive evolutionary psychology theory regarding female and male short-term and long-term mating strategies which are argued to be dependent on several different goals and vary depending on the environment. Men and women are predicted to have both similar and different strategies depending on the circumstances. For instance, long- term mating could result in female selection of consistent behavior in males. The theory included many predictions that could be empirically tested. The theory is argued to have received extensive empirical support in subsequent research. It has also been developed further. Terri D. Conley et al. has argued that other empirical evidence support smaller or non-existing gender differences and social theories such as stigma, socialization, and double standards.
|This section relies too much on references to primary sources. (July 2014)|
Differences in intelligence or mental power have long been a hot topic among researchers and scholars. With the advent of the concept of g or general intelligence some form of empiricism was allowed, but results are often inconsistent with studies showing either no differences or advantages for both sexes, with most showing a slight advantage for males. One study did find some advantage for women in later life, while another found that male advantages on some cognitive tests are minimized when controlling for socioeconomic factors. The differences in average IQ between men and women are small in magnitude and inconsistent in direction, although the variability of male scores has been found to be greater than that of females, resulting in more males than females in the top and bottom of the IQ distribution.
According to the 1995 report "Intelligence: Knowns and Unknowns" by the American Psychological Association, "Most standard tests of intelligence have been constructed so that there are no overall score differences between females and males." Lewis Terman's analysis of scores on the first version of the Stanford-Binet IQ test concluded "Accordingly, our data, which for the most part agree with the results of others, justify the conclusion that the intelligence of girls, at least up to 14 years, does not differ materially from that of boys either as regards the average level or the range of distribution." There are however differences in the capacity of males and females in performing certain tasks, such as rotation of objects in space, often categorized as spacial ability. Other traditionally male advantages, such as in the field of mathematics is not so clear-cut.
The results from research on sex differences in memory are mixed and inconsistent, with some studies showing no difference, and others showing a female or male advantage. Most studies have found no sex differences in short term memory, the rate of memory decline due to aging, or memory of visual stimuli. Females have been found to have an advantage in recalling auditory and olfactory stimuli, experiences, faces, names, and the location of objects in space. However, males show an advantage in recalling "masculine" events. A study examining sex differences in performance on the California Verbal Learning Test found that males performed better on Digit Span Backwards and on reaction time, while females were better on short-term memory recall and Symbol-Digit Modalities Test.
A study was conducted to explore regions within the brain that are activated during working memory tasks in males versus females. Four different tasks of increasing difficulty were given to 9 males and 8 females. Functional magnetic resonance imaging was used to measure brain activity. The lateral prefrontal cortices, the parietal cortices and caudates were activated in both genders. With more difficult tasks, more brain tissue was activated. The left hemisphere was predominantly activated in females' brains, whereas there was bilateral activation in males' brains. This suggests some sort of gender difference in the brain organization involved in working memory.
Although research on sex differences in aggression show that males are generally more likely to display aggression than females, how much of this is due to social factors and gender expectations is unclear. Aggression is closely linked with cultural definitions of "masculine" and "feminine." In some situations women show equal or more aggression than men; for example, women are more likely to use direct aggression in private, where other people cannot see them, and are more likely to use indirect aggression in public. Eagly and Steffen suggested in their meta-analysis of data on sex and aggression that beliefs about the negative consequences of violating gender expectations affect how both genders behave regarding aggression. Men are more likely to be the targets of displays of aggression and provocation than females. Studies by Bettencourt and Miller show that when provocation is controlled for, sex differences in aggression are greatly reduced. They argue that this shows that gender-role norms play a large part in the differences in aggressive behavior between men and women. Psychologist Anne Campbell argues that females are more likely to use indirect aggression, and that "cultural interpretations have 'enhanced' evolutionarily based sex differences by a process of imposition which stigmatises the expression of aggression by females and causes women to offer exculpatory (rather than justificatory) accounts of their own aggression."
The relationship between testosterone and aggression is unclear, and a causal link has not been conclusively shown. Some studies indicate that testosterone levels may be affected by environmental and social influences. The relationship is difficult to study since the only reliable measure of brain testosterone is from a lumbar puncture which is not done for research purposes and many studies have instead used less reliable measures such as blood testosterone. In humans, males engage in crime and especially violent crime more than females. The involvement in crime usually rises in the early teens to mid teens which happen at the same time as testosterone levels rise. Most studies support a link between adult criminality and testosterone although the relationship is modest if examined separately for each sex. However, nearly all studies of juvenile delinquency and testosterone are not significant. Most studies have also found testosterone to be associated with behaviors or personality traits linked with criminality such as antisocial behavior and alcoholism.
In species that have high levels of male physical competition and aggression over females, males tend to be larger and stronger than females. Humans have modest general body sexual dimorphism on characteristics such as height and body mass. However, this may understate the sexual dimorphism regarding characteristics related to aggression since females have large fat stores. The sex differences are greater for muscle mass and especially for upper body muscle mass. Men's skeleton, especially in the vulnerable face, is more robust. Another possible explanation, instead of intra-species aggression, for this sexual dimorphism may be that it is an adaption for a sexual division of labor with males doing the hunting. However, the hunting theory may have difficulty explaining differences regarding features such as stronger protective skeleton, beards (not helpful in hunting but they increase the perceived size of the jaws and perceived dominance which may helpful in intra-species male competition), and greater male ability at interception (greater targeting ability can be explained by hunting).
There are evolutionary theories regarding male aggression in specific areas such as sociobiological theories of rape and theories regarding the high degree of abuse against stepchildren (the Cinderella effect).
Cross-cultural research has shown gender differences on the domains and facets of the Big Five personality traits. For example, women consistently report higher Neuroticism, Agreeableness, warmth (an extraversion facet) and openness to feelings, and men often report higher assertiveness (a facet of extraversion) and openness to ideas as assessed by the NEO-PI-R. Gender differences in personality traits are largest in prosperous, healthy, and egalitarian cultures in which women have more opportunities that are equal to those of men. Differences in the magnitude of sex differences between more or less developed world regions were due to differences between men not women in these respective regions. That is, men in highly developed world regions were less neurotic, extraverted, conscientious and agreeable compared to men in less developed world regions. Women, on the other hand tended not to differ in personality traits across regions. Researchers have speculated that resource poor environments (that is, countries with low levels of development) may inhibit the development of gender differences, whereas resource rich environments facilitate them. This may be because males require more resources than females in order to reach their full developmental potential. The authors argued that due to different evolutionary pressures, men may have evolved to be more risk taking and socially dominant, whereas women evolved to be more cautious and nurturant. Hunter-gatherer societies in which humans originally evolved may have been more egalitarian than later agriculturally oriented societies. Hence, the development of gender inequalities may have acted to constrain the development of gender differences in personality that originally evolved in hunter-gatherer societies. As modern societies have become more egalitarian again it may be that innate sex differences are no longer constrained and hence manifest more fully than in less developed cultures. Currently, this hypothesis remains untested, as gender differences in modern societies have not been compared with those in hunter-gatherer societies.
A personality trait directly linked to emotion and empathy where gender differences exist (see below) is Machiavellianism. Individuals who score high on this dimension are emotionally cool; this allows them to detach from others as well as values, and act egoistically rather than driven by affect, empathy or morality. In large samples of US college students males are on average more Machiavellian than females; in particular, males are over-represented among very high Machiavellians, while females are overrepresented among low Machiavellians.
A meta-analysis of scientific studies concluded that men prefer working with things and women prefer working with people. When interests were classified by RIASEC type http://en.wikipedia.org/wiki/Holland_Codes (Realistic, Investigative, Artistic, Social, Enterprising, Conventional), Men showed 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.
Some studies argue that this is related to the subject's perceived gender identity and gender expectations. Additionally, culture impacts gender differences in the expression of emotions. This may be explained by the different social roles men and women have in different cultures, and by the status and power men and women hold in different societies, as well as the different cultural values various societies hold. Some studies have found no differences in empathy between men and women, and suggest that perceived gender differences are the result of motivational differences. Some researchers argue that because differences in empathy disappear on tests where it is not clear that empathy is being studied, men and women do not differ in ability, but instead in how empathetic they would like to appear to themselves and others.
An evolutionary explanation for the difference is that understanding and tracking relationships and reading others' emotional states was particularly important for women in prehistoric societies for tasks such as caring for children and social networking. On the other hand, social skills and relationship tracking are also essential to tasks typically undertaken by men in prehistoric societies (such as hunting as a team, trading, etc.), so it is difficult to see how this evolutionary explanation favors the development of empathy in women over men.
When measured with an affect intensity measure, women reported greater intensity of both positive and negative affect than men. Women also reported a more intense and more frequent experience of affect, joy, and love but also experienced more embarrassment, guilt, shame, sadness, anger, fear, and distress. Experiencing pride was more frequent and intense for men than for women. In imagined frightening situations, such as being home alone and witnessing a stranger walking towards your house, women reported greater fear. Women also reported more fear in situations that involved "a male's hostile and aggressive behavior" (281) In anger-eliciting situations, women communicated more intense feelings of anger than men. Women also reported more intense feelings of anger in relation to terrifying situations, especially situations involving a male protagonist. Emotional contagion refers to the phenomenon of a person's emotions becoming similar to those of surrounding people. Women have been reported to be more responsive to this.
Women are stereotypically more emotional and men are stereotypically angrier. When lacking substantial emotion information they can base judgments on, people tend to rely more on gender stereotypes. Results from a study conducted by Robinson and colleagues implied that gender stereotypes are more influential when judging others' emotions in a hypothetical situation.
There are documented differences in socialization that could contribute to sex differences in emotion and to differences in patterns of brain activity. An American Psychological Association article states that, "boys are generally expected to suppress emotions and to express anger through violence, rather than constructively". A child development researcher at Harvard University argues that boys are taught to shut down their feelings, such as empathy, sympathy and other key components of what is deemed to be pro-social behavior. According to this view, differences in emotionality between the sexes are theoretically only socially-constructed, rather than biological.
Context also determines a man or woman's emotional behavior. Context-based emotion norms, such as feeling rules or display rules, "prescribe emotional experience and expressions in specific situations like a wedding or a funeral," independent of the person's gender. In situations like a wedding or a funeral, the activated emotion norms apply to and constrain every person in the situation. Gender differences are more pronounced when situational demands are very small or non-existent as well as in ambiguous situations. During these situations, gender norms "are the default option that prescribes emotional behavior." (290-1)
Scientists in the field distinguish between emotionality and the expression of emotion: Associate Professor of Psychology Ann Kring said, "It is incorrect to make a blanket statement that women are more emotional than men, it is correct to say that women show their emotions more than men." In two studies by Kring, women were found to be more facially expressive than men when it came to both positive and negative emotions. These researchers concluded that men and women experience the same amount of emotion, but that women are more likely to express their emotions.
Women are known to have anatomically differently shaped tear glands than men as well as having more of the hormone prolactin, which is present in tear glands, as adults. While girls and boys cry at roughly the same amount at age 12, by age 18, women generally cry four times more than men, which could be explained by higher levels of prolactin.
Women show a significantly greater activity in the left amygdala when encoding and remembering emotionally arousing pictures (such as mutilated bodies.) Men and women tend to use different neural pathways to encode stimuli into memory. While highly emotional pictures were remembered best by all participants in one study, as compared to emotionally neutral images, women remembered the pictures better than men. This study also found greater activation of the right amygdala in men and the left amygdala in women. On average, women use more of the left cerebral hemisphere when shown emotionally arousing images, while men use more of their right hemisphere. Women also show more consistency between individuals for the areas of the brain activated by emotionally disturbing images.
A 2003 worldwide survey by the Pew Research Center found that overall women stated that they were somewhat happier than men with their lives. Compared to the previous report five years earlier women more often reported progress with their lives while men were more optimistic about the future. Women were more concerned about home and family issues than men who were more concerned about issues outside the home. Men were happier than women regarding the family life and more optimistic regarding the children's future.
Childhood conduct disorder and adult antisocial personality disorder as well as substance use disorders are more common in men. Many mood disorders, anxiety disorders, and eating disorders are more common in women. One explanation is that men tend to externalize stress while women tend to internalize it. Gender differences vary to some degree for different cultures. Women are more likely than men to show unipolar depression. One 1987 study found little empirical support for several proposed explanations, including biological ones, and argued that when depressed women tend to ruminate which may lower the mood further while men tend to distract themselves with activities. This may develop from men and women being raised differently.
Men and women do not differ on their overall rates of psychopathology; however, certain disorders are more prevalent in women, and vice versa. Women have higher rates of anxiety and depression (internalizing disorders) and men have higher rates of substance abuse and antisocial disorders (externalizing disorders). It is believed that divisions of power and the responsibilities set upon each sex are critical to this predisposition. Namely, women earn less money than men do, they tend to have jobs with less power and autonomy, and women are more responsive to problems of people in their social networks. These three differences can contribute to women's predisposition to anxiety and depression. It is believed that socializing practices that encourage high self-regard and mastery would benefit the mental health of both men and women.
One study interviewed 18,572 respondents, aged 18 and over, about 15 phobic symptoms. These symptoms would yield diagnoses based on criteria for agoraphobia, social phobia, and simple phobia. Women had significantly higher prevalence rates of agoraphobia and simple phobia; however, there were no differences found between men and women in social phobia. The most common phobias for both men and women involved spiders, bugs, mice, snakes, and heights. The biggest differences between men and women in these disorders were found on the agoraphobic symptoms of “going out of the house alone” and “being alone”, and on two simple phobic symptoms, involving the fear of “any harmless or dangerous animal” and “storms,” with relatively more women having both phobias. There were no differences in the age of onset, reporting a fear on the phobic level, telling a doctor about symptoms, or the recall of past symptoms.
One study interviewed 2,181 people in Detroit, aged 18–45, seeking to explain gender differences in exposure to traumatic events and in the development or emergence of post traumatic stress disorder following this exposure. It was found that lifetime prevalence of traumatic events was a little higher in men than in women. However, following exposure to a traumatic event, the risk for PTSD was two times higher in women. It is believed this difference is due to the greater risk women have of developing PTSD after a traumatic event that involved assaultive violence. In fact, the probability of a woman developing PTSD following assaultive violence was 36% compared to 6% of men. The duration of PTSD is longer in women, as well.
Men and women are both equally likely at developing symptoms of schizophrenia, but the onset occurs earlier for men. It has been suggested that sexually dimorphic brain anatomy, the differential effects of estrogens and androgens, and the heavy exposure of male adolescents to alcohol and other toxic substances can lead to this earlier onset in men. It is believed that estrogens have a protective effect against the symptoms of schizophrenia. Although, it has been shown that other factors can contribute to the delayed onset and symptoms in women, estrogens have a large effect, as can be seen during a pregnancy. In pregnancy, estrogen levels are rising in women, so women who have had recurrent acute episodes of schizophrenia did not usually break down. However, after pregnancy, when estrogen levels have dropped, women tend to suffer from postpartum psychoses. Also, psychotic symptoms are exacerbated when, during the menstrual cycle, estrogen levels are at their lowest. In addition, estrogen treatment has yielded beneficial effects in patients with schizophrenia.
Pathological gambling has been known to have a higher prevalence rate, 2:1, in men to women. One study chose to identify gender-related differences by examining male and female gamblers, who were using a gambling helpline. There was 562 calls placed, and of this amount, 62.1% were men, and 37.9% were women. Male gamblers were more likely to report problems with strategic forms of gambling (blackjack or poker), and female gamblers were more likely to report problems with nonstrategic forms, such as slots or bingo. Male gamblers were also more likely to report a longer duration of gambling than women. Female gamblers were more likely to report receiving mental health treatment that was not related to gambling. Male gamblers were more likely to report a drug problem or being arrested on account of gambling. There were high rates of debt and psychiatric symptoms related to gambling observed in both groups of men and women.
There are also differences regarding gender and suicide. Males in Western societies are much more likely to die from suicide despite females having more suicide attempts.
The "extreme male brain theory" views autism as an extreme version of male-female differences regarding "systemizing" and empathizing abilities. The "imprinted brain theory" argues that autism and psychosis are contrasting disorders on a number of different variables and that this is caused by an unbalanced genomic imprinting favoring paternal genes (autism) or maternal genes (psychosis).
Fundamental sex differences in genetics, hormones and brain structure and function may manifest as distal cultural phenomena (e.g., males as primary combatants in warfare, the primarily female readership of romance novels, etc.). In addition, differences in socialization of males and females may have the effect of decreasing or increasing the magnitude of sex differences.
Division of labor between the sexes
One study argues that a division of labor between sexes developed relatively late, 45,000-10,000 years ago. It may have given humans an important advantage over Neanderthals who likely did not have a similar division of labor and who had similarly robust skeletons for both sexes. The paper also argues that gender roles varied across early human cultures and that the division of labor is not only due to innate differences between sexes but that much of it was learned.
In January 2005, Lawrence Summers, president of Harvard University, unintentionally provoked a public controversy when several attendees discussed with reporters some statements he made during his lunchtime presentation at an economics conference at the National Bureau of Economic Research. In analyzing the disproportionate numbers of men over women in high-end science and engineering jobs he suggested that part of discrepancy may be due in part to the conflict between employers' demands for high time commitments and women's disproportionate role in the raising of children. He also suggested that well documented greater variability among men (in comparison to women) on tests of cognitive abilities  may be due to intrinsic factors, adding that he "would like nothing better than to be proved wrong." The controversy generated a great deal of media attention; it contributed to the resignation of Summers the following year, and led Harvard to commit $50 million to the recruitment and hiring of women faculty. Stimulated by this controversy, in May 2005, Harvard University psychology professors Steven Pinker and Elizabeth Spelke debated "The Science of Gender and Science".
In 2006, Danish psychologist and intelligence researcher Helmuth Nyborg was temporarily suspended from his position at Aarhus University, after being accused of scientific misconduct in relation to the documentation of a peer-reviewed paper appearing in the journal Personality and Individual Differences, in which he showed a 3.15-point IQ advantage of men over women. This led to a review of his work by an investigative committee. Nyborg was defended — and the university criticized — by other researchers in the intelligence field.
In July 2012, IQ researcher Jim Flynn was widely misquoted in the media as claiming that women had surpassed men on IQ tests for the first time in a century. In a 2012 lecture, Flynn responded by denouncing the media reports as distortions, and made it clear that his data instead showed a rough parity between the sexes in a few countries on the Raven's Matrices for boys and girls between the ages of 14 and 18. Women, he argued, had previously scored lower than men on the Raven's tests, but reached equality with men in these nations as a result of exposure to modernity by entering the professions and being allowed greater educational access. Flynn stated that the minute variations that did appear were statistically negligible and were not attributable to differences in cognitive ability.
- Neuroscience and intelligence
- Heritability of IQ
- List of psychological tests by gender difference
- Sex differences in humans
- Sex differences in human physiology
- Sociology of gender
- Mealey, L. (2000). Sex differences. NY: Academic Press.
- Geary, D. C. (2009) Male, Female: The Evolution of Human Sex Differences. Washtington, D.C.: American Psychological Association
- Richardson, S. S. (2013) Sex Itself: The Search for Male and Female in the Human Genome Hardcover. Chicago: Chicago University Press.
- Becker, J.B., Berkley, K. J., Geary, N., & Hampson, E. (2007) Sex Differences in the Brain: From Genes to Behavior by NY: Oxford University Press.
- Helmuth, N. (1994). Hormones, Sex, and Society. NY: Praeger
- Symons, D. (1979). The evolution of human sexuality. Oxford: Oxford University Press.
- Wilson, M. & Daly, M. (1983) Sex, evolution and behavior.
- Low, B. (2000). Why sex matters. NJ: Princeton University Press.
- Geary, D. C. (2009) Male, Female: The Evolution of Human Sex Differences. Washington, D.C.: American Psychological Association
- Gray, P. B. (2013). Evolution and Human Sexual Behavior. Boston: Harvard University Press.
- Lippa, R. A. (2009). Gender, Nature, and Nurture. NY: LEA.
- Halpern, D. F. (2011). Sex Differences in Cognitive Abilities (4th Edition). NY: Psychology Press
- Fisher, M., et al. (2013). Evolution's Empress: Darwinian Perspectives on the Nature of Women. Oxford: Oxford University Press
- Fausto-Sterling, A., (2012). Sex/Gender: Biology in a Social World. NY: Routledge.
- Halpern, D. (2012). Sex Differences in Cognitive Abilities (4th Ed.). NY: Psychology Press. p. 35 - 36.
- Francis, D., & Kaufer, D. (2011). Beyond Nature vs. Nurture. The Scientist. October 1, 2011
- Standards of evidence for designed sex differences
- Bourke CH, Harrell CS, Neigh GN; Harrell; Neigh (August 2012). "Stress-induced sex differences: adaptations mediated by the glucocorticoid receptor". Hormones and Behavior 62 (3): 210–8. doi:10.1016/j.yhbeh.2012.02.024. PMC 3384757. PMID 22426413.
- Mills, M.E. (2011). "Sex Difference vs. Gender Difference? Oh, I'm So Confused!" Psychology Today.
- Buss, D.M. (2011). Evolutionary Psychology: The New Science of the Mind. Monterrey: Brooks-Cole
- Andersson, M. (1994). Sexual selection. Princeton: Princeton University Press.
- Miller, Geoffrey (2000). The Mating Mind. Anchor Books, a division of Random House, Inc. (First Anchor Books Edition, April 2001). New York, NY. Anchor ISBN 0-385-49517-X
- Bateman, A. J. (1948). "Intra-sexual selection in Drosophila". Heredity 2 (Pt. 3): 349–821. doi:10.1038/hdy.1948.21. PMID 18103134.
- Buss, D. M.; Schmitt, D. P. (1993). "Sexual strategies theory: an evolutionary perspective on human mating". Psychological review 100 (2): 204–232. doi:10.1037/0033-295x.100.2.204.
- Buss, D. M. (1989). "Conflict between the sexes: strategic interference and the evocation of anger and upset". Journal of personality and social psychology 56 (5): 735–747. doi:10.1037/0022-35188.8.131.525.
- A dictionary of genetics (8. ed.). Oxford [u.a.]: Oxford Univ. Press. 2012. ISBN 9780199766444.
|last1=in Authors list (help)
- Zirkle, Conrad 1946. The discovery of sex-influenced, sex limited and sex-linked heredity. In Ashley Montagu M.F. (ed) Studies in the history of science and learning offered in homage to George Sarton on the occasion of his sixtieth birthday. New York: Schuman, p167–194.
- King R.C; Stansfield W.D. & Mulligan P.K. 2006. A dictionary of genetics. 7th ed, Oxford University Press. ISBN 0-19-530761-5
- Sánchez FJ1 Vilain E.; Vilain, E (2010). "Genes and brain sex differences". Prog Brain Res. 186 (2010;186): 65–76. doi:10.1016/B978-0-444-53630-3.00005-1. PMID 21094886.
- Trabzuni, D., et al. (2013). Widespread sex differences in gene expression and splicing in the adult human brain, Nature Communications 4, Article number: 2771 doi:10.1038/ncomms3771
- Margaret M. McCarthy; Anthony P. Auger; Tracy L. Bale; Geert J. De Vries; Gregory A. Dunn; Nancy G. Forger; Elaine K. Murray; Bridget M. Nugent; Jaclyn M. Schwarz; Melinda E. Wilson (Oct 14, 2009). "The Epigenetics of Sex Differences in the Brain.". J Neurosci. 29 (29(41)): 12815–12823. doi:10.1523/JNEUROSCI.3331-09.2009. PMC 2788155. PMID 19828794.
- Cosgrove, Kelly P.; Mazure, Carolyn M.; Staley, Julie K. (2007). "Evolving Knowledge of Sex Differences in Brain Structure, Function, and Chemistry". Biological Psychiatry 62 (8): 847–55. doi:10.1016/j.biopsych.2007.03.001. PMC 2711771. PMID 17544382.
- Fine, Cordelia (2010). Delusions of Gender: How Our Minds, Society, and Neurosexism Create Difference. W. W. Norton. ISBN 0-393-06838-2.[page needed]
- Kaiser, Anelis; Haller, Sven; Schmitz, Sigrid; Nitsch, Cordula (2009). "On sex/gender related similarities and differences in fMRI language research". Brain Research Reviews 61 (2): 49–59. doi:10.1016/j.brainresrev.2009.03.005. PMID 19406148.
- Jordan-Young, Rebecca (Sep 2010). Brain Storm: The Flaws in the Science of Sex Differences. Harvard University Press. ISBN 0-674-05730-9.[page needed]
- Arnold, Arthur P. (2004). "Sex chromosomes and brain gender". Nature Reviews Neuroscience 5 (9): 701–8. doi:10.1038/nrn1494. PMID 15322528.
- Lopes, Alexandra M.; Ross, Norman; Close, James; Dagnall, Adam; Amorim, António; Crow, Timothy J. (2006). "Inactivation status of PCDH11X: Sexual dimorphisms in gene expression levels in brain". Human Genetics 119 (3): 267–75. doi:10.1007/s00439-006-0134-0. PMID 16425037.
- O'Brien, Jodi (2009). Encyclopedia of Gender and Society. Los Angeles: SAGE. p. 343. ISBN 1-4129-0916-3.
- Kimura, Doreen (1999). Sex and Cognition. Cambridge, MA: MIT Press. ISBN 978-0-262-11236-9
- Ho, KC; Roessmann, U; Straumfjord, JV; Monroe, G (1980). "Analysis of brain weight. I. Adult brain weight in relation to sex, race, and age". Archives of pathology & laboratory medicine 104 (12): 635–9. PMID 6893659.
- Ankney, C. Davison (1992). "Sex differences in relative brain size: The mismeasure of woman, too?". Intelligence 16 (3–4): 329–36. doi:10.1016/0160-2896(92)90013-H.
- Marner, Lisbeth; Nyengaard, Jens R.; Tang, Yong; Pakkenberg, Bente (2003). "Marked loss of myelinated nerve fibers in the human brain with age". The Journal of Comparative Neurology 462 (2): 144–52. doi:10.1002/cne.10714. PMID 12794739.
- Gur, RC; Turetsky, BI; Matsui, M; Yan, M; Bilker, W; Hughett, P; Gur, RE (1999). "Sex differences in brain gray and white matter in healthy young adults: Correlations with cognitive performance". The Journal of neuroscience 19 (10): 4065–72. PMID 10234034.
- Leonard, C. M.; Towler, S.; Welcome, S.; Halderman, L. K.; Otto, R.; Eckert, M. A.; Chiarello, C. (2008). "Size Matters: Cerebral Volume Influences Sex Differences in Neuroanatomy". Cerebral Cortex 18 (12): 2920–31. doi:10.1093/cercor/bhn052. PMC 2583156. PMID 18440950.
- Lüders, Eileen; Steinmetz, Helmuth; Jäncke, Lutz (2002). "Brain size and grey matter volume in the healthy human brain". NeuroReport 13 (17): 2371–4. doi:10.1097/00001756-200212030-00040. PMID 12488829.
- Nucifora, P. G., Verma, R., Lee, S. K., & Melhem, E. R. (2007). Diffusion-tensor MR imaging and tractography: exploring brain microstructure and connectivity. RADIOLOGY-OAK BROOK IL-, 245(2), 367.
- Ingalhalikar, M., Smith, A., Parker, D., Satterthwaite, T. D., Elliott, M. A., Ruparel, K., ... & Verma, R. (2014). Sex differences in the structural connectome of the human brain. Proceedings of the National Academy of Sciences, 111(2), 823-828.
- "Sex and context: hormones and primate sexual motivation.". Hormone Behaviour 40 (2): 339–357. 2001. doi:10.1006/hbeh.2001.1696. PMID 11534996.
- Wallen, K (2001). "Sex and context: hormones and primate sexual motivation". Hormones and Behavior 40 (2): 339–57. doi:10.1006/hbeh.2001.1696. PMID 11534996.
- Van Anders, S. M.; Hamilton, L. D.; Watson, N. V. (2007). "Multiple partners are associated with higher testosterone in North American men and women". Hormones and Behavior 51 (3): 454–459. doi:10.1016/j.yhbeh.2007.01.002. PMID 17316638.
- Gangestad, S. W.; Thornhill, R. (1998). "Menstrual cycle variation in women's preferences for the scent of symmetrical men". Proceedings of the Royal Society of London 265 (1399): 927–933. doi:10.1098/rspb.1998.0380. PMC 1689051. PMID 9633114.
- Gangestad, S. W.; Thornhill, R.; Garver-Apgar, C. E. (2005). "Adaptations to ovulation implications for sexual and social behaviour". Current Directions in Psychological Science 14 (6): 312–316. doi:10.1111/j.0963-7214.2005.00388.x.
- "Reiner & Gearhart's NEJM Study on Cloacal Exstrophy - Review by Vernon Rosario, M.D., Ph.D".
- http://alicedreger.com/HCR_update.html[full citation needed]
- Neisser, Ulric; Boodoo, Gwyneth; Bouchard, Thomas J., Jr.; Boykin, A. Wade; Brody, Nathan; Ceci, Stephen J.; Halpern, Diane F.; Loehlin, John C.; Perloff, Robert et al. (1996). "Intelligence: Knowns and Unknowns". American Psychologist 51 (2): 77–101. doi:10.1037/0003-066X.51.2.77.
- Berenbaum, Sheri A.; Hines, Melissa (1992). "Early Androgens Are Related to Childhood Sex-Typed Toy Preferences". Psychological Science 3 (3): 203–6. doi:10.1111/j.1467-9280.1992.tb00028.x. JSTOR 40062786.
- Alexander, G.M.; Hines, M. (2002). "Sex differences in response to children's toys in nonhuman primates (Cercopithecus aethiops sabaeus)". Evolution & Human Behavior 23 (6): 467–479. doi:10.1016/s1090-5138(02)00107-1.
- Hassett, J.M.; Siebert, E.R.; Wallen, K. (2008). "Sex differences in rhesus monkey toy preferences parallel those of children". Hormones and Behavior 54 (3): 359–364. doi:10.1016/j.yhbeh.2008.03.008. PMC 2583786. PMID 18452921.
- Auyeung, B.; Baron-Cohen, S.; Ashwin, E.; Knickmeyer, R.; Taylor, K.; Hackett, G.; Hines, M. (2009). "Fetal testosterone predicts sexually differentiated childhood behavior in girls and in boys". Psychol. Sci. 20 (2): 144–148. doi:10.1111/j.1467-9280.2009.02279.x.
- Vasey, P.L.; Bartlett, N.H. (2007). "What can the Samoan "Fa'afafine" teach us about the Western concept of gender identity disorder in childhood?". Perspect. Biol. Med. 50 (4): 481–490. doi:10.1353/pbm.2007.0056. PMID 17951883.
- Schuett, Wiebke; Tregenza, Tom; Dull, Sasha R. X. (2009-08-19). "Sexual selection and animal personality". Biological Reviews 85 (2): 217–246. doi:10.1111/j.1469-185X.2009.00101.x. PMID 19922534.
- Buss, David Michael; Schmitt, David P. (2011). "Evolutionary Psychology and Feminism". Sex Roles 64 (9–10): 768–787. doi:10.1007/s11199-011-9987-3.
- Conley, T. D.; Moors, A. C.; Matsick, J. L.; Ziegler, A.; Valentine, B. A. (2011). "Women, Men, and the Bedroom: Methodological and Conceptual Insights That Narrow, Reframe, and Eliminate Gender Differences in Sexuality". Current Directions in Psychological Science 20 (5): 296–300. doi:10.1177/0963721411418467.
- Lynn, Richard (1999). "Sex differences in intelligence and brain size: A developmental theory". Intelligence 27: 1–12. doi:10.1016/S0160-2896(99)00009-4.
- Lynn, Richard; Irwing, Paul (2004). "Sex differences on the progressive matrices: A meta-analysis". Intelligence 32 (5): 481–498. doi:10.1016/j.intell.2004.06.008.
- Irwing, Paul; Lynn, Richard (2005). "Sex differences in means and variability on the progressive matrices in university students: A meta-analysis". British Journal of Psychology 96 (4): 505–24. doi:10.1348/000712605X53542. PMID 16248939.
- Lynn, Richard (1994). "Sex differences in intelligence and brain size: A paradox resolved". Personality and Individual Differences 17 (2): 257–71. doi:10.1016/0191-8869(94)90030-2.
- Blinkhorn, Steve (2005). "Intelligence: A gender bender". Nature 438 (7064): 31–2. Bibcode:2005Natur.438...31B. doi:10.1038/438031a. PMID 16267535.
- Irwing, Paul; Lynn, Richard (2006). "Intelligence: Is there a sex difference in IQ scores?". Nature 442 (7098): E1; discussion E1–2. Bibcode:2006Natur.442E...1I. doi:10.1038/nature04966. PMID 16823409.
- Jackson, Douglas N.; Rushton, J. Philippe (2006). "Males have greater g: Sex differences in general mental ability from 100,000 17- to 18-year-olds on the Scholastic Assessment Test". Intelligence 34 (5): 479–486. doi:10.1016/j.intell.2006.03.005.
- Nyborg, Helmuth (2005). "Sex-related differences in general intelligence g, brain size, and social status". Personality and Individual Differences 39 (3): 497–509. doi:10.1016/j.paid.2004.12.011.
- Keith, Timothy Z.; Reynolds, Matthew R.; Patel, Puja G.; Ridley, Kristen P. (2008). "Sex differences in latent cognitive abilities ages 6 to 59: Evidence from the Woodcock–Johnson III tests of cognitive abilities". Intelligence 36 (6): 502–25. doi:10.1016/j.intell.2007.11.001.
- Jorm, Anthony F.; Anstey, Kaarin J.; Christensen, Helen; Rodgers, Bryan (2004). "Gender differences in cognitive abilities: The mediating role of health state and health habits". Intelligence 32: 7–23. doi:10.1016/j.intell.2003.08.001.
- Baumeister, Roy F (2001). Social psychology and human sexuality: essential readings. Psychology Press. ISBN 978-1-84169-019-3.[page needed]
- Baumeister, Roy F. (2010). Is there anything good about men?: how cuflourish by exploiting men. Oxford University Press. ISBN 978-0-19-537410-0.[page needed]
- Hedges, L.; Nowell, A (1995). "Sex differences in mental test scores, variability, and numbers of high-scoring individuals". Science 269 (5220): 41–5. Bibcode:1995Sci...269...41H. doi:10.1126/science.7604277. PMID 7604277.
- Colom, R; García, LF; Juan-Espinosa, M; Abad, FJ (2002). "Null sex differences in general intelligence: Evidence from the WAIS-III". The Spanish journal of psychology 5 (1): 29–35. doi:10.1017/s1138741600005801. PMID 12025362.
- Deary, Ian J.; Irwing, Paul; Der, Geoff; Bates, Timothy C. (2007). "Brother–sister differences in the g factor in intelligence: Analysis of full, opposite-sex siblings from the NLSY1979". Intelligence 35 (5): 451–6. doi:10.1016/j.intell.2006.09.003.
- Terman, Lewis M. (1916). 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. Boston: Houghton Mifflin. p. 71. OCLC 186102.
- 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]
- Halpern, Diane F., Sex differences in cognitive abilities, Psychology Press, 2000, ISBN 0-8058-2792-7, ISBN 978-0-8058-2792-7[page needed]
- Speck, Oliver; Ernst, Thomas; Braun, Jochen; Koch, Christoph; Miller, Eric; Chang, Linda (2000). "Gender differences in the functional organization of the brain for working memory". NeuroReport 11 (11): 2581–5. doi:10.1097/00001756-200008030-00046. PMID 10943726.
- Chrisler, Joan C; Donald R. McCreary. Handbook of Gender Research in Psychology. Springer, 2010. ISBN 9781441914644.[page needed]
- Eagly, Alice H.; Steffen, Valerie J. (1986). "Gender and aggressive behavior: A meta-analytic review of the social psychological literature". Psychological Bulletin 100 (3): 309–30. doi:10.1037/0033-2909.100.3.309. PMID 3797558.
- Bettencourt, B. Ann; Miller, Norman (1996). "Gender differences in aggression as a function of provocation: A meta-analysis". Psychological Bulletin 119 (3): 422–47. doi:10.1037/0033-2909.119.3.422. PMID 8668747.
- Campbell, Anne (1999). "Staying alive: Evolution, culture, and women's intrasexual aggression". Behavioral and Brain Sciences 22 (2). doi:10.1017/S0140525X99001818.
- Baron, Robert A., Deborah R. Richardson, Human Aggression: Perspectives in Social Psychology, Springer, 2004, ISBN 0-306-48434-X, 9780306484346
- Albert, D.J.; Walsh, M.L.; Jonik, R.H. (1993). "Aggression in humans: What is its biological foundation?". Neuroscience & Biobehavioral Reviews 17 (4): 405–25. doi:10.1016/S0149-7634(05)80117-4. PMID 8309650.
- Coccaro, Emil F.; Beresford, Brendan; Minar, Philip; Kaskow, Jon; Geracioti, Thomas (2007). "CSF testosterone: Relationship to aggression, impulsivity, and venturesomeness in adult males with personality disorder". Journal of Psychiatric Research 41 (6): 488–92. doi:10.1016/j.jpsychires.2006.04.009. PMID 16765987.
- Constantino, John N.; Grosz, Daniel; Saenger, Paul; Chandler, Donald W.; Nandi, Reena; Earls, Felton J. (1993). "Testosterone and Aggression in Children". Journal of the American Academy of Child & Adolescent Psychiatry 32 (6): 1217–22. doi:10.1097/00004583-199311000-00015. PMID 8282667.
- Hillbrand, Marc, Nathaniel J. Pallone, The psychobiology of aggression: engines, measurement, control: Volume 21, Issues 3-4 of Journal of Offender Rehabilitation, Psychology Press, 1994, ISBN 1-56024-715-0, ISBN 978-1-56024-715-9
- Handbook of Crime Correlates; Lee Ellis, Kevin M. Beaver, John Wright; 2009; Academic Press[page needed]
- Puts, David A. (2010). "Beauty and the beast: Mechanisms of sexual selection in humans". Evolution and Human Behavior 31 (3): 157–175. doi:10.1016/j.evolhumbehav.2010.02.005.
- Costa, Paul, Jr.; Terracciano, Antonio; McCrae, Robert R. (2001). "Gender differences in personality traits across cultures: Robust and surprising findings". Journal of Personality and Social Psychology 81 (2): 322–31. doi:10.1037/0022-35184.108.40.2062. PMID 11519935.
- Schmitt, David P.; Realo, Anu; Voracek, Martin; Allik, Jüri (2008). "Why can't a man be more like a woman? Sex differences in Big Five personality traits across 55 cultures". Journal of Personality and Social Psychology 94 (1): 168–82. doi:10.1037/0022-35220.127.116.11. PMID 18179326.
- Christie, R. & Geis, F. (1970) "Studies in Machiavellianism". NY: Academic Press.[page needed]
- Gunnthorsdottir, Anna; McCabe, Kevin; Smith, Vernon (2002). "Using the Machiavellianism instrument to predict trustworthiness in a bargaining game". Journal of Economic Psychology 23: 49–66. doi:10.1016/S0167-4870(01)00067-8.
- Su, Rong; Rounds, James; Armstrong, Patrick (2009). "Men and Things, Women and People: A Meta-Analysis of Sex Differences in Interests". Psychological Bulletin 135 (6): 859–884. doi:10.1037/a0017364. PMID 19883140.
- Hall, Judith A. (1978). "Gender effects in decoding nonverbal cues". Psychological Bulletin 85 (4): 845–857. doi:10.1037/0033-2909.85.4.845.
- Judith A. Hall (1984): Nonverbal sex differences. Communication accuracy and expressive style. 207 pp. Johns Hopkins University Press.[page needed]
- Judith A. Hall, Jason D. Carter & Terrence G. Horgan (2000): Gender differences in nonverbal communication of emotion. Pp. 97 - 117 i A. H. Fischer (ed.): Gender and emotion: social psychological perspectives. Cambridge University Press.
- Agneta H. Fischer & Anthony S. R. Manstead (2000): The relation between gender and emotions in different cultures. Pp. 71 - 94 i A. H. Fischer (ed.): Gender and emotion: social psychological perspectives. Cambridge University Press.
- Niedenthal, P.M., Kruth-Gruber, S., & Ric, F. (2006). Psychology and emotion. (Principles of Social Psychology series). ISBN 1-84169-402-9. New York: Psychology Press[page needed]
- Ickes, W. (1997). Empathic accuracy. New York: The Guilford Press.
- Klein, K. J. K.; Hodges, S. D. (2001). "Gender Differences, Motivation, and Empathic Accuracy: When it Pays to Understand". Personality and Social Psychology Bulletin 27 (6): 720–730. doi:10.1177/0146167201276007.
- Schaffer, Amanda (July 2, 2008). "The Sex Difference Evangelists". Slate.
- Geary, David C. (1998). Male, female: The evolution of human sex differences. American Psychological Association. ISBN 1-55798-527-8.[page needed]
- Brody, Leslie R.; Lovas, Gretchen S.; Hay, Deborah H. (1995). "Gender differences in anger and fear as a function of situational context". Sex Roles 32: 47–78. doi:10.1007/BF01544757.
- Hatfield, E., Cacioppo, J.T., & Rapson, R.L. (1994) Emotional contagion. New York: Cambridge University Press.[page needed]
- Wilson, Tracy V. "How Women Work" How Stuff Works. Accessed April 2, 2008.
- Robinson, Michael D.; Johnson, Joel T.; Shields, Stephanie A. (1998). "The Gender Heuristic and the Database: Factors Affecting the Perception of Gender-Related Differences in the Experience and Display of Emotions". Basic and Applied Social Psychology 20 (3): 206–219. doi:10.1207/s15324834basp2003_3.
- Murray, Bridgett "Boys to Men: Emotional Miseducation". APA.
- Reeves, Jamie Lawson "Women more likely than men to but emotion into motion". Vanderbilt News. Accessed April 3, 2008.
- Wood, Samual; Wood, Ellen; Boyd Denise (2004). "World of Psychology, The (Fifth Edition)" , Allyn & Bacon ISBN 0-205-36137-4
- Motluk, Alison. "Women's better emotional recall explained". NewScientist. July 22, 2002. Accessed April 2, 2008.
- Canli, T.; Desmond, J. E.; Zhao, Z.; Gabrieli, J. D. E. (2002). "Sex differences in the neural basis of emotional memories". Proceedings of the National Academy of Sciences 99 (16): 10789–10794. Bibcode:2002PNAS...9910789C. doi:10.1073/pnas.162356599.
- Global Gender Gaps: Women Like Their Lives Better, Pew Research Center October 29, 2003, http://www.pewglobal.org/2003/10/29/global-gender-gaps/
- Afifi, M (2007). "Gender differences in mental health". Singapore medical journal 48 (5): 385–91. PMID 17453094.
- Nolen-Hoeksema, Susan (1987). "Sex differences in unipolar depression: Evidence and theory". Psychological Bulletin 101 (2): 259–82. doi:10.1037/0033-2909.101.2.259. PMID 3562707.
- Rosenfield, Sarah. "Gender and mental health: Do women have more psychopathology, men more, or both the same (and why)?". In Horwitz, Allan V.; Scheid, Teresa L. A handbook for the study of mental health: Social contexts, theories, and systems. New York: Cambridge University Press. pp. 348–60.
- Bourdon, Karen H.; Boyd, Jeffrey H.; Rae, Donald S.; Burns, Barbara J.; Thompson, James W.; Locke, Ben Z. (1988). "Gender differences in phobias: Results of the ECA community survey". Journal of Anxiety Disorders 2 (3): 227–241. doi:10.1016/0887-6185(88)90004-7.
- Breslau, N. "Gender differences in trauma and posttraumatic stress disorder". Retrieved 28 June 2012.
- Seeman, Mary. "Psychopathology in Women and Men: Focus on Female Hormones". Retrieved 28 June 2012.
- Potenza, Marc. "Gender-Related Differences in the Characteristics of Problem Gamblers Using a Gambling Helpline". Retrieved 28 June 2012.
- The Oxford Handbook of Evolutionary Psychology, Edited by Robin Dunbar and Louise Barret, Oxford University Press, 2007, Chapter 16 The evolution of empathizing and systemizing: assortative mating of two strong systemizers and the cause of autism, Simon Baron-Cohen.
- Schlomer, Gabriel L.; Del Giudice, Marco; Ellis, Bruce J. (2011). "Parent–offspring conflict theory: An evolutionary framework for understanding conflict within human families". Psychological Review 118 (3): 496–521. doi:10.1037/a0024043. PMID 21604906.
- Badcock, Christopher; Crespi, Bernard (2008). "Battle of the sexes may set the brain". Nature 454 (7208): 1054–5. Bibcode:2008Natur.454.1054B. doi:10.1038/4541054a. PMID 18756240.
- Stefan Lovgren. "Sex-Based Roles Gave Modern Humans an Edge, Study Says". National Geographic News. Retrieved 2008-02-03.
- Bombardieri, Marcella (January 17, 2005). "Summers' remarks on women draw fire", The Boston Globe, reporting the remarks of Larry Summers at a January 2005 conference.
- Transcript of Summers' remarks at NBER Conference on Diversifying the Science & Engineering Workforce.
- Summers' initial response to controversy.
- Lehrke, R. (1997). Sex linkage of intelligence: The X-Factor. NY: Praeger.[page needed]
- Lubinski, D.; Benbow, C. P. (2006). "Study of Mathematically Precocious Youth After 35 Years: Uncovering Antecedents for the Development of Math-Science Expertise". Perspectives on Psychological Science 1 (4): 316–45. doi:10.1111/j.1745-6916.2006.00019.x. JSTOR 40212176.
- Hedges, L. V.; Nowell, A. (1995). "Sex differences in mental scores, variability, and numbers of high scoring individuals". Science 269 (5220): 41–45. doi:10.1126/science.7604277. PMID 7604277.
- Hernandez, Javier C. (Feb 22, 2006). "Summers resigns: Shortest term since civil war; Bok will be interim chief", Harvard Crimson.
- Seward, Zarachy M. (May 16, 2005). "University Will Commit $50M to Women in Science", Harvard Crimson.
- "The Science Of Gender And Science", Edge.
- Letter from Douglas K. Detterman to Aarhus University in support of Prof. Nyborg.
- Letter from Steven Pinker to Aarhus University in defence of Prof. Nyborg, December 9, 2009.
- Kaufman, S.B. Men, Women, and IQ: Setting the Record Straight. Psychology Today. Jul 20 2012. Retrieved 2012-07-27.
- Flynn, Jim; Rossi-Casé, Lilia (2011). "Modern women match men on Raven's Progressive Matrices". Personality and Individual Differences 50 (6): 799–803. doi:10.1016/j.paid.2010.12.035.
- Born, M. Ph.; Bleichrodt, N.; Van Der Flier, H. (1987). "Cross-Cultural Comparison of Sex-Related Differences on Intelligence Tests: A Meta-Analysis". Journal of Cross-Cultural Psychology 18 (3): 283–314. doi:10.1177/0022002187018003002.
- Colom, R; García, LF; Juan-Espinosa, M; Abad, FJ (2002). "Null sex differences in general intelligence: Evidence from the WAIS-III". The Spanish journal of psychology 5 (1): 29–35. doi:10.1017/s1138741600005801. PMID 12025362.
- Haier, Richard J.; Benbow, Camilla Persson (1995). "Sex differences and lateralization in temporal lobe glucose metabolism during mathematical reasoning". Developmental Neuropsychology 11 (4): 405–414. doi:10.1080/87565649509540629.
- Lynn, Richard; Irwing, Paul; Cammock, Thomas (2002). "Sex differences in general knowledge". Intelligence 30: 27–39. doi:10.1016/S0160-2896(01)00064-2.
- Lynn, Richard (1999). "Sex differences in intelligence and brain size: A developmental theory". Intelligence 27: 1–12. doi:10.1016/S0160-2896(99)00009-4.