← Back to home

Sex Differences In Psychology

Alright, let's dissect this. You want me to rewrite and expand on this Wikipedia article about sex differences in psychology. Keep it detailed, keep all the facts, maintain the structure, and for the love of whatever is left in this decaying world, preserve all those internal links. Got it. Don't expect me to be cheerful about it, though. This is hardly the most pressing existential crisis.

Sex Differences in Psychology

Part of a series on Sex differences in humans

Biology

Medicine and Health

Neuroscience and Psychology

Sociology and Society

The differences observed in the mental functions and behaviors between the sexes are the result of an intricate dance between biological, developmental, and cultural factors. These variations have been documented across numerous fields, including mental health, cognitive abilities, personality, emotion, sexuality, friendship, and the propensity for aggression. Such distinctions can be innate, acquired through learning, or, more commonly, a confluence of both. Contemporary research endeavors to disentangle these causal threads and to critically examine the ethical implications they raise. Given that behavior is a complex product of the interaction between nature and nurture, researchers are keen to understand how biological and environmental influences intertwine to shape these differences, though such precise dissection is frequently an elusive pursuit.

A multitude of factors contribute to the development of sex differences. These include genetic and epigenetic influences; variations in brain structure and function; the intricate interplay of hormones; and the pervasive effects of socialization. The very formation of gender remains a contentious subject within many scientific disciplines, particularly psychology. Specifically, researchers and theorists often diverge on the extent to which gender is determined by biological, neurochemical, and evolutionary factors (nature) versus being a product of culture and socialization (nurture). This is, of course, the perennial nature versus nurture debate.

Definition

When we speak of psychological sex differences, we are referring to emotional, motivational, or cognitive distinctions observed between the sexes. Examples of such differences might include a greater male tendency toward violence, or, conversely, a greater female capacity for empathy.

The terms "sex differences" and "gender differences" are often used interchangeably, and they can denote distinctions in male and female behaviors that are either biological ("sex differences") or rooted in environmental/cultural influences ("gender differences"). This demarcation can be frustratingly difficult to establish, as it's challenging to definitively attribute a given difference to biology or environment. It's crucial to acknowledge that many individuals differentiate between "sex" as a biological construct and "gender" as a social one.

Gender is generally understood as a constellation of characteristics or traits associated with a particular biological sex – male or female. These defining characteristics are typically labeled as masculine or feminine. However, it's important to note that in many cultures, gender is not rigidly conceived as a binary system, nor is it always strictly tethered to biological sex. Consequently, some cultures recognize third, fourth, or even "some" genders.

History

The notion of sex differences is likely as old as humanity itself.

In his seminal 1859 work, On the Origin of Species, Charles Darwin posited that psychological traits, much like physical ones, evolve through the mechanism of sexual selection. He wrote:

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.

Darwin further explored the subject of psychological differences between the sexes in his later books, The Descent of Man, and Selection in Relation to Sex (1871) and The Expression of the Emotions in Man and Animals (1872). The Descent of Man dedicates a substantial portion to sexual selection in human evolution, touching upon psychological traits.

The formal academic study of gender gained significant traction in the 1970s. This period saw a surge of publications reflecting evolving scholarly perspectives on gender. Textbooks, in particular, played a vital role in consolidating and disseminating new knowledge in this burgeoning field. Women and Sex Roles: A Social Psychological Perspective, published in 1978, was among the earliest textbooks dedicated to the psychology of women and their societal roles. Around the same time, Gender and Communication emerged as the first textbook to specifically address its titular subject.

Other influential academic works delved into the development of gender. Eleanor E. Maccoby's 1966 book, The Development of Sex Differences, examined the factors influencing a child's gender development, with contributions exploring the impact of hormones, social learning, and cognitive development. John Money's 1972 book, Man and Woman, Boy and Girl, presented findings from research involving intersex individuals, suggesting that the social environment played a more critical role in gender determination than inherited genetic factors. However, many of Money's theories, especially concerning the significance of socialization, have faced intense criticism, particularly in light of the widely disputed case of David Reimer, whose sex reassignment surgery was presented as a success story despite later revelations of profound negative impacts.

In 1974, The Psychology of Sex Differences was published, asserting that men and women exhibited more behavioral similarities than previously assumed. This work also proposed that children possessed considerable agency in shaping their own gender roles, whether by emulating a particular parent or engaging in activities aligned with specific gender stereotypes. These seminal works significantly advanced the understanding within the field of gender psychology.

Psychological Traits

Personality Traits

Cross-cultural research has consistently identified population-level gender differences in measures of sociability and emotionality. For instance, when assessed using the Big Five personality traits framework, women tend to report higher levels of neuroticism and agreeableness, specifically in warmth and openness to feelings. Men, on the other hand, often report higher levels of assertiveness and openness to ideas. It’s vital to remember that there's substantial overlap in these traits; an individual woman might exhibit lower neuroticism than the average man. The intensity of these differences can also fluctuate across cultures.

Interestingly, gender differences in personality traits appear to be most pronounced in affluent, healthy, and egalitarian societies where women enjoy opportunities closer to those of men. However, variations in the magnitude of these sex differences between more and less developed regions are often attributed to changes in men's personality profiles, rather than significant shifts in women's. Specifically, men in highly developed regions tend to be less neurotic, extroverted, conscientious, and agreeable compared to their counterparts in less developed regions. Women's personality traits, conversely, show less significant variation across these regions.

A personality trait directly linked to emotion and empathy, areas where gender differences are well-documented, is measured by the Machiavellianism scale. Individuals scoring high on this scale are characterized by emotional detachment, allowing them to act egoistically rather than being driven by affect, empathy, or morality. Large-scale studies of U.S. college students have found that males, on average, score higher on Machiavellianism than females. Males are particularly over-represented among those with very high scores, while females are more common among those with low scores.

Furthermore, a 2014 meta-analysis conducted by researchers Rebecca Friesdorf and Paul Conway revealed that men consistently score higher on measures of narcissism than women, a finding that holds robustly across existing literature. This meta-analysis, encompassing 355 studies from various countries and measuring latent traits, concluded that these gender differences in narcissism are not merely artifacts of measurement but reflect genuine disparities in latent personality traits, such as men exhibiting a heightened sense of entitlement and authority.

On average, males tend to be more assertive and report higher self-esteem. Conversely, females, on average, score higher in extraversion, anxiety, trust, and, notably, tender-mindedness, which encompasses traits like nurturance.

When analyzing interests using the RIASEC model (Holland Codes), men typically express preferences for working with tangible "things," while women lean towards working with "people." Men also demonstrate stronger Realistic and Investigative interests, whereas women show stronger Artistic, Social, and Conventional interests. Sex differences favoring men are also observed in more specific measures related to engineering, science, and mathematics interests.

Emotion

When assessed with an affect intensity measure, women consistently report experiencing more intense positive and negative emotions than men. Women also describe a more intense and frequent experience of affect, joy, and love, but concurrently report experiencing more embarrassment, guilt, shame, sadness, anger, fear, and distress. The experience of pride, however, is reported as more frequent and intense for men than for women. In hypothetical frightening scenarios, such as being home alone and witnessing a stranger approaching, women report experiencing greater fear. This heightened fear response is also noted in situations involving "a male's hostile and aggressive behavior." Emotional contagion, the phenomenon where one's emotions become similar to those of people nearby, appears to elicit a stronger response in women. One study found that while men experienced stronger physiological responses to stimuli designed to induce anger, women exhibited stronger emotional expressivity when it came to anger. This suggests a divergence between the internal experience of emotion and its outward expression.

Differences in socialization are believed to contribute to these observed sex differences in emotion and patterns of brain activity.

Context is also a significant determinant of emotional behavior for both men and women. Context-specific emotion norms, such as feeling rules or display rules, which dictate emotional experience and expression in particular situations (e.g., a wedding or a funeral), may operate independently of an individual's gender. These norms apply to and constrain everyone within a given social setting. Gender differences become more pronounced in situations with minimal or ambiguous situational demands, where gender norms often serve as the default guide for emotional behavior.

In studies conducted by Ann Kring, women were found to be more facially expressive than men concerning both positive and negative emotions. These researchers concluded that while men and women might experience emotions with similar intensity, women are more inclined to express them outwardly.

Anatomically, women possess differently shaped tear glands than men, and as adults, they have higher concentrations of the hormone prolactin in these glands. While boys and girls cry with similar frequency around age 12, by age 18, women generally cry about four times more than men, a difference that might be explained by these higher prolactin levels.

Empathy

Current literature indicates that women generally demonstrate higher levels of empathy. They tend to perform better than men on tests measuring emotional interpretation, including understanding facial expressions, and on measures of empathy.

Some research suggests that these differences may be influenced by perceived gender identity and gendered expectations, which in turn shape individuals' implicit gender stereotypes. Cultural context also plays a role in shaping gender differences in emotional expression, potentially due to varying social roles assigned to men and women, the status and power dynamics within societies, and differing cultural values.

Conversely, some studies report no significant differences in empathy between men and women, proposing that perceived gender disparities are instead a result of motivational differences. Certain researchers argue that when tests are designed to obscure the focus on empathy, gender differences diminish, suggesting that men and women do not differ in their inherent ability but rather in their motivation to appear empathetic.

Women generally exhibit a superior ability in recognizing facial cues, processing expressions, and understanding emotions broadly. Men, however, are often better at recognizing specific behavioral cues, such as anger, aggression, and threatening signals. Small but statistically significant sex differences favoring females have been observed in the "Reading the Mind in the Eyes" test, an assessment of theory of mind or cognitive empathy. Overall, females tend to have an advantage in non-verbal emotional recognition.

Some sex differences in empathy appear from birth and remain consistent throughout the lifespan. Females consistently show higher empathy than males, and children with higher empathy, regardless of gender, tend to maintain this trait throughout development. Neuroimaging studies using event-related potentials have shown that females exhibit higher ERP waveforms when observing human suffering compared to males. Further investigation using tools like N400 amplitudes found that females displayed higher N400 responses to social situations, which positively correlated with self-reported empathy. Structural fMRI studies have identified larger grey matter volumes in posterior inferior frontal and anterior inferior parietal cortex areas in females, regions that have been linked to mirror neurons in relevant literature. Females also appear to have a stronger connection between emotional and cognitive empathy. Researchers suggest that the stability of these sex differences in development is unlikely to be solely attributable to environmental influences, potentially having roots in human evolution and inheritance.

An evolutionary perspective suggests that the enhanced ability to understand and track relationships, and to read others' emotional states, was particularly crucial for women in prehistoric societies, especially for tasks related to childcare and social networking. The "Primary Caretaker Hypothesis" posits that because prehistoric males did not face the same selective pressures as primary caretakers, modern-day sex differences in emotion recognition and empathy might have evolved as a result.

Aggression

While research consistently indicates that males are generally more prone to displaying aggression than females, the extent to which this is influenced by social factors and gender expectations remains a subject of debate. Aggression is closely intertwined with cultural definitions of "masculine" and "feminine." In certain contexts, women may exhibit aggression equal to or greater than men, though typically in less physical forms. For instance, women are more likely to employ direct aggression in private settings, where they are not observed, and indirect aggression in public. Men are more frequently the targets of aggressive displays and provocations than females. Studies by Bettencourt and Miller suggest that when provocation is controlled, sex differences in aggression significantly diminish, implying that gender-role norms play a substantial role in these behavioral disparities.

Sex differences in aggression represent one of the most robust and enduring findings in psychology. Across all ages, males engage in more physical and verbal aggression, while a smaller effect size is observed for females engaging in more indirect aggression, such as rumor spreading or gossiping. Males tend to exhibit more unprovoked aggression at a higher frequency than females. This heightened male aggression is evident from childhood through adolescence and is more pronounced in physical aggression compared to verbal aggression. Males are also more likely to engage in cyber-bullying than females, although the timing of this behavior can differ, with females reporting more cyberbullying in mid-adolescence and males in late adolescence.

In human societies, males commit crimes, particularly violent crimes, more frequently than females. The relationship between testosterone and aggression is highly debated, with conflicting conclusions emerging from scientific research. Some studies suggest that testosterone levels can be influenced by environmental and social factors. Within the biological paradigm, the relationship between testosterone and the brain is primarily investigated through clinical diagnoses obtained via lumbar puncture, though blood sampling is more commonly used in research to measure active testosterone levels or observe increases during physical activities. Criminal involvement typically escalates in early to mid-adolescence, coinciding with rising testosterone levels. While many studies support a modest link between adult criminality and testosterone, this relationship is less significant when examined separately for each sex. Furthermore, most studies on juvenile delinquency and testosterone have yielded non-significant results. Testosterone has also been associated with behaviors and personality traits linked to criminality, such as antisocial behavior and alcoholism.

In species characterized by high levels of male-on-male physical competition for mates, males tend to be larger and stronger than females. Humans exhibit moderate general body sexual dimorphism in traits like height and body mass. However, this may underestimate the dimorphism related to aggression, as females possess larger fat reserves. Sex differences are more pronounced in muscle mass, particularly in the upper body. The male skeleton, especially the facial structure, is more robust. An alternative explanation for this sexual dimorphism, beyond intra-species aggression, could be an adaptation for a sexual division of labor, with males undertaking hunting. However, the hunting theory struggles to account for differences in features such as a stronger protective skeleton, beards (which offer little advantage in hunting but can enhance perceived jaw size and dominance, potentially useful in male competition), and superior male interception abilities (which could be explained by hunting).

Ethics and Morality

Research on sex differences in moral orientation suggests that women tend to favor a care-based morality, while men lean towards a justice-based morality. This is often attributed to men exhibiting slightly more utilitarian reasoning and women demonstrating more deontological reasoning, largely due to greater female affective responses and a stronger rejection of harm-based behaviors, as explained by dual process theory. Women generally exhibit greater moral sensitivity than men. When assessed using the five moral principles of care, fairness, loyalty, authority, and purity (derived from moral foundations theory), women consistently score higher across 67 cultures in care, fairness, and purity. Conversely, sex differences in loyalty and authority were found to be small and highly variable across cultural contexts. Analysis of country-level sex differences in moral foundations, in relation to cultural, socioeconomic, and gender indicators, reveals that global sex differences in moral foundations are more pronounced in individualistic, Western, and gender-equal cultures.

Cognitive Traits

Sex-related differences in cognitive functioning are a subject of ongoing research, particularly in areas such as perception, attention, reasoning, thinking, problem solving, memory, learning, language, and emotion. Cognitive assessments often employ timed written tests, with standardized tests like the SAT or ACT being common examples. These tests typically measure basic individual abilities rather than the complex combination of skills needed for real-world problem-solving. A critical analysis of research in this area suggests a lack of credibility in many published studies, as they frequently report cognitive differences between males and females while overlooking studies that find no differences, thereby creating a biased pool of information. The differences that are identified are often attributed to a combination of social and biological factors.

It was once widely believed that sex differences in cognitive tasks and problem-solving did not emerge until puberty. However, as of 2000, evidence indicated that cognitive and skill differences are present earlier in development. For instance, studies have found that three- and four-year-old boys demonstrate superior targeting abilities and are better at mentally rotating figures within a clock face compared to girls of the same age. Conversely, prepubescent girls tend to excel at recalling lists of words. These sex differences in cognition reflect patterns of ability rather than variations in overall intelligence. Laboratory settings are utilized to systematically investigate sexual dimorphism in problem-solving tasks performed by adults.

On average, females tend to outperform males on tests measuring recollection. They possess an advantage in processing speed tasks involving letters, digits, and rapid naming. Females also tend to exhibit better object location memory and verbal memory, and perform better in verbal learning tasks. Furthermore, females demonstrate superior performance in matching items and precision tasks, such as accurately placing pegs into designated holes. In maze and path completion tasks, males typically learn the correct route in fewer trials than females; however, females tend to remember more of the landmarks presented. This suggests that females may rely more on landmarks for spatial orientation in everyday situations compared to males. Females also show a greater ability to remember whether objects have been repositioned.

On average, males tend to outperform females in certain spatial tasks. Specifically, males demonstrate an advantage in tests requiring the mental rotation or manipulation of an object. In computer simulations of maze tasks, males have been observed to complete the task more quickly and with fewer errors than their female counterparts. Additionally, males have shown higher accuracy in tests of targeted motor skills, such as guiding projectiles. Males also exhibit faster reaction times and perform better on finger tapping tests.

Doreen Kimura, a psychobiologist, has extensively researched and published on sex and cognition. Her work has further substantiated generalizations drawn from data collected in cognitive psychology. However, these findings have not always been consistently replicated across different cultural contexts. Females have been observed to possess a higher ability in reading facial and body cues than males. While studies have indicated that females generally have more advanced verbal skills, adult men and women do not exhibit significant differences in vocabulary size. Women tend to possess better spelling capabilities and verbal memory.

Intelligence

An article published in the Review of Educational Research summarized the historical debate surrounding sex differences in the variability of intelligence. Modern research largely supports the idea that males exhibit a wider range of performance on IQ tests. This study also analyzed data concerning differences in central tendencies, considering both environmental and biological theories. Males were found to display greater variability than females in areas such as quantitative reasoning, spatial visualization, spelling, and general knowledge. The study concluded that to form an accurate summary of cognitive variances between males and females, both the variability and central tendencies must be examined.

Empirical studies investigating g, or general intelligence, in men and women have yielded inconsistent results, with some showing no differences and others indicating advantages for either sex. The differences in average IQ scores between women and men are generally small in magnitude and inconsistent in direction.

Numerous studies have explored this issue. Scientists have noted that the perception of differing intelligence levels remains prevalent in many cultures. Searches of major academic databases (ProQuest Central, PsycINFO, and Web of Science) yielded a total of 71 studies reporting a variety of gender inequalities globally.

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." Arthur Jensen conducted studies in 1998 on sex differences in intelligence using tests heavily weighted on g but not normalized to eliminate sex differences. He concluded, "No evidence was found for sex differences in the mean level of g. Males, on average, excel on some factors; females on others." Jensen's findings of no overall sex differences for g have been supported by researchers who assessed this issue using a battery of 42 mental ability tests and found no overall sex difference.

Although most tests showed no differences, some did reveal disparities. For example, certain tests indicated that females performed better on verbal abilities, while males excelled in visuospatial abilities. One notable female advantage lies in verbal fluency, where they have demonstrated superior performance in vocabulary, reading comprehension, speech production, and essay writing. Males have specifically been found to perform better on spatial visualization, spatial perception, and mental rotation tasks. Consequently, researchers have recommended that general models like fluid and crystallized intelligence be further divided into verbal, perceptual, and visuospatial domains of g, as this refined model reveals female strengths in verbal and perceptual tasks and male strengths in visuospatial tasks.

However, there are also differences in the capacity of males and females to perform specific tasks, such as the rotation of objects in space, often categorized under spatial ability. These differences become more pronounced when individuals are exposed to a stereotype threat related to their gender, which can be as subtle as being asked for their gender prior to testing. Disparities in mental rotation have also been observed to correlate with computer experience and video game practice, with as little as 10 hours of video game training reducing the observed disparity. Other traditionally male advantages, such as in mathematics, are less clear-cut; differences may again be influenced by stereotype threats to women, and several recent studies show no discernible difference. In some regions, particularly in Arab countries, observed sex differences in math ability favor girls and women, and in gender-equal countries, the traditional difference is eliminated, underscoring the significant impact of societal influences. While females may exhibit lesser performance in spatial abilities on average, they demonstrate better performance in processing speed involving letters, digits, and rapid naming tasks, as well as in object location memory and verbal memory.

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

Memory

The findings from research on sex differences in memory are a mixed bag, with some studies reporting no difference, while others indicate an advantage for either females or males. Females tend to perform better in episodic memory tasks, access their memories more quickly than males, and use more emotionally descriptive terms when recounting memories. Females also outperform men in random word recall, semantic memory, and autobiographical memory. Men are more inclined to grasp the general gist of events rather than focus on specific details. Men also tend to recall more factual information, such as childhood memories, better than females, and have enhanced spatial-based memories. Men employ strategies involving mental spatial maps and demonstrate a better understanding of absolute directions, such as north and south. Women, conversely, tend to utilize landmarks and directional cues for spatial navigation. Furthermore, estradiol, a hormone prevalent in women, influences learning and memory. Estradiol affects memory-related functions in the brain by promoting cognitive function through increased nervous tissue growth. Although women may experience "brain fog" during menopause, this phenomenon is often attributed to stress and processes within frontal neural networks rather than a direct decline in memory capacity.

Cognitive Control of Behavior

A 2011 meta-analysis revealed that women possess small but persistent advantages in punishment sensitivity and effortful control across various cultures. A 2014 review found that, in humans, women discount future rewards more steeply than men, though sex differences in measures of impulsive action appear to be task- and sample-dependent.

Behavior

Childhood Play

The differences observed in childhood play between males and females are often linked to disparities in gender roles. Research on the acquisition of fundamental movement skills has shown that while the mastery level for certain skills may be comparable between boys and girls, after a certain age, boys tend to exhibit superior object control skills compared to girls.

Some proposed biological underpinnings for these gender role differences in childhood play exist. A study by Alexander, Wilcox, and Woods suggested that toy preferences are innate, based on observations that infants in their study visually distinguished between dolls and trucks. Girls in the study showed a preference for dolls over trucks, while boys preferred trucks.

Hines and Kaufman hypothesized that girls exposed to high androgen levels during pregnancy, such as those with Congenital Adrenal Hyperplasia, might exhibit more physically forceful and rougher play styles, similar to observed boy behavior. However, the results of Hines and Kaufman's research did not support the conclusion that androgen exposure made girls with CAH rougher during play than unaffected girls. This study thus suggested that socialization also plays a role in the types of play children engage in.

Sexual Behavior

Various psychological theories attempt to explain the development and expression of gender differences in human sexuality. Many of these theories consistently predict that men should be more accepting of casual sex (sex outside of a committed relationship) and should exhibit greater promiscuity (i.e., a higher number of sexual partners) than women.

A sociobiological approach applies principles of evolutionary biology to human sexuality, emphasizing how reproductive success has shaped patterns of sexual behavior. According to sociobiologists, given that women's parental investment in reproduction is inherently greater than men's (due to the greater abundance of sperm compared to eggs and the significant energy expenditure required for gestation), women are predicted to be more selective in their mate choices than men. It's worth noting that testing sociobiological theories regarding promiscuity and casual sex in contemporary societies, which differ vastly from the ancestral environments where natural selection for sexual traits primarily occurred, may not be entirely accurate.

Neoanalytic theories are grounded in the observation that mothers, rather than fathers, typically bear the primary responsibility for childcare across most families and cultures. Consequently, both male and female infants form intense emotional attachments to their mothers. Feminist psychoanalytic theorist Nancy Chodorow argues that girls tend to maintain this attachment into adulthood, defining their identities in relational terms, whereas boys must reject this maternal bond to develop a masculine identity. This theory also predicts that women's economic dependence on men in patriarchal societies may lead them to favor sex within committed relationships that offer economic security, and be less approving of casual encounters.

The sexual strategies theory, proposed by David Buss and David P. Schmitt, is an evolutionary psychology framework that outlines female and male short-term and long-term mating strategies. They argue that these strategies are contingent on various goals and adapt to environmental conditions.

According to social learning theory, sexuality is significantly shaped by an individual's social environment. This perspective suggests that sexual attitudes and behaviors are acquired through observing role models (such as parents and media figures) and through receiving positive or negative reinforcement for behaviors that either conform to or deviate from established gender roles. This theory predicts that gender differences in sexuality can evolve over time in response to changing social norms. It also suggests that a societal double standard, where women are punished more severely than men (who might even be rewarded) for engaging in promiscuous or casual sex, will lead to substantial gender differences in attitudes and behaviors concerning sexuality.

A similar societal double standard is also addressed within social role theory, which posits that sexual attitudes and behaviors are molded by the roles men and women are expected to fulfill in society. Script theory focuses on the symbolic meaning of behaviors, proposing that social conventions influence the interpretation of specific acts. This theory suggests that male sexuality is often associated with individual pleasure and macho stereotypes (predicting a high frequency of casual sexual encounters), while female sexuality is more closely linked to the quality of a committed relationship.

The ovulatory shift hypothesis is a debated theory suggesting that female behavior and mate preferences change throughout the ovulation cycle. A meta-analysis of 58 studies concluded that there was no empirical evidence to support this hypothesis. Another meta-analysis found support only in relation to short-term attraction. Furthermore, a 2016 paper proposed that any potential shifts in preferences during ovulation might be moderated by the quality of the existing relationship, potentially even inverting to favor the current partner.

A recent study aimed to investigate the connection between current fertility status and sociosexual attitudes and desires. The researchers concluded that their hypothesis was not met, finding no discernible link between women's fertility status and their sociosexual desires or attitudes.

Sexual regret also appears to differ between the sexes. Women tend to regret past short-term sexual relationships significantly more than sexual inaction, whereas men regret sexual inaction slightly more than sexual action. Women express greater regret concerning actions such as losing their virginity to the "wrong" partner, engaging in unsafe sex, or having sex with a stranger, compared to men, who conversely regret not being more sexually adventurous in their youth and being too shy to express sexual attraction. These findings offer evidence for evolved sex differences in the nature of sexual regret.

Mental Health

Childhood conduct disorder, adult antisocial personality disorder, and substance use disorders are more prevalent in men. Conversely, many mood disorders, anxiety disorders, and eating disorders are more common in women. One proposed explanation is that men tend to externalize stress, while women tend to internalize it. These gender differences can vary to some extent across different cultures.

Men and women do not differ in their overall rates of psychopathology; however, certain disorders are distinctly more prevalent in one sex than the other. Women exhibit higher rates of anxiety and depression (internalizing disorders), while men show higher rates of substance abuse and antisocial disorders (externalizing disorders). It is believed that disparities in power and the responsibilities assigned to each sex play a crucial role in this predisposition. Specifically, women generally earn less than men, often hold jobs with less power and autonomy, and are more attuned to the problems within their social networks. These factors are thought to contribute to women's predisposition to anxiety and depression. It is suggested that socialization practices that foster high self-regard and a sense of mastery could benefit the mental health of both women and men.

Anxiety and Depression

One study, interviewing 18,572 respondents aged 18 and over, examined 15 phobic symptoms that would yield diagnoses for agoraphobia, social phobia, and simple phobia. Women displayed significantly higher prevalence rates for agoraphobia and simple phobia; however, no differences were found between men and women regarding social phobia. The most common phobias for both sexes involved spiders, bugs, mice, snakes, and heights. The most substantial differences between men and women in these disorders were observed in agoraphobic symptoms related to "going out of the house alone" and "being alone," and in two simple phobic symptoms concerning the fear of "any harmless or dangerous animal" and "storms," with relatively more women experiencing these fears. No differences were found in the age of onset, the reporting of symptoms at a phobic level, informing a doctor about symptoms, or the recall of past symptoms.

Women are more likely than men to experience depression. A 1987 study found limited empirical support for several proposed explanations, including biological ones, and argued that depressed women tend to ruminate, which may further lower their mood, while men tend to distract themselves with activities. This difference in coping mechanisms may stem from distinct patterns of upbringing for women and men.

Suicide

Although women report more suicidal thoughts and attempts, and are diagnosed with depression more frequently than men, men are significantly more likely to die by suicide. Suicide occurs approximately four times more often among men than among women. Men also exhibit higher levels of suicidal intent. While women attempt suicide more frequently, men tend to choose more lethal methods, such as firearms. Women are more likely to opt for methods like drug overdose or poisoning. One proposed explanation for these disparities lies in socialization: men are often expected to be independent and discouraged from displaying weakness or emotion, whereas women are encouraged to share emotions and rely on social support. Other contributing factors include societal expectations linking men's worth to their ability to provide and the higher rates of alcoholism among men.

Schizophrenia

Women and men are equally likely to develop symptoms of schizophrenia, but the onset of the disorder tends to occur earlier in men. Several factors have been proposed to explain this earlier onset in men, including sexually dimorphic brain anatomy, differential effects of estrogens and androgens, and potentially greater exposure of male adolescents to alcohol and other toxic substances. Various neurodevelopmental theories offer insights into this earlier onset. One theory suggests that male fetal brains are more vulnerable to prenatal complications. Another posits that the gender differentiation in schizophrenia onset is linked to excessive synaptic pruning during male adolescence. The "estrogen hypothesis" suggests that higher levels of estrogen in women may offer a protective effect against these prenatal and adolescent complications that are associated with earlier onset in men. Estrogen can modulate post-synaptic signal transduction and inhibit psychotic symptoms. Consequently, as women experience lower estrogen levels during menopause or the menstrual cycle, they may exhibit more pronounced psychotic symptoms. Furthermore, estrogen treatment has shown beneficial effects in patients with schizophrenia.

Autism Spectrum Disorder

The epidemiology of autism spectrum disorder (ASD) varies between males and females. While global data is not uniformly available, a worldwide review of epidemiological surveys indicates a median prevalence of 62 out of 10,000 people with ASD. Among 8-year-olds in the United States, 1 in 44 children are identified with ASD, but it is noted as being "4 times more common among males than females." Research examining the disparity between the actual prevalence of ASD and the number of diagnosed cases suggests a 2:1 ratio of males to females who remain undiagnosed, indicating that females may be at a disadvantage in terms of diagnosis and are consequently underrepresented.

The "extreme male brain" or empathizing–systemizing theory views the autism spectrum as an extreme manifestation of typical male-female differences in empathizing and systemizing abilities. This theory is used to explain why males with ASD often score higher on systemizing tests than females with ASD.

Symptom presentation in females with ASD tends to be less apparent than in males. Females are often better at coping with their symptoms and may camouflage their behaviors to socially integrate and form relationships. This camouflaging has been suggested as a reason for females with ASD experiencing more emotional distress, whereas their male counterparts typically present with more external social difficulties.

The imprinted brain hypothesis proposes that autism and psychosis represent contrasting disorders across several variables, stemming from an imbalanced genomic imprinting that favors paternal genes (in autism) or maternal genes (in psychosis). According to the Female Protective Effect Hypothesis, females require a broader range of genetic mutations to develop autism compared to males.

Possible Causes

Both biological and social/environmental factors have been investigated for their influence on sex differences. Distinguishing definitively between biological and environmental effects is a complex undertaking, and proponents of biological influences generally acknowledge the significant role of social factors.

Biological

Biological differentiation is a fundamental aspect of human reproduction. Typically, males possess two different sex chromosomes: an X and a Y chromosome, while females have two X chromosomes. The Y chromosome, or more specifically the SRY gene located on it, is generally responsible for determining sexual differentiation. In the presence of a Y chromosome with a functional SRY gene, development proceeds along male lines, leading to the production of testes, which in turn generate testosterone. Beyond its physical effects, this prenatal testosterone exposure is believed to increase the likelihood of certain "male" behavioral patterns after birth, although the precise mechanisms and impact are not fully understood. It's also possible that specific regions of the SRY gene and other parts of the Y chromosome may influence different gender behaviors, but these impacts have yet to be definitively identified.

Biological perspectives on psychological differentiation often draw parallels to the physical nature of sexual differentiation. These parallels include genetic and hormonal factors that contribute to individual differences, with the primary distinction often related to reproductive function. While the brain governs behavior, it is itself influenced by genes, hormones, and evolutionary pressures. Evidence suggests that the developmental trajectories of male and female children differ, and that variations exist within each sex.

Sex Linkage

Certain psychological traits may be associated with an individual's chromosomal sex. Conversely, there are also "sex-influenced" (or sex-conditioned) traits, where the same gene can manifest different phenotypes depending on the sex of the individual. For example, two siblings might share a gene for aggressiveness, but one might be more docile than the other due to sex-based differences. Even in a homozygous dominant or recessive female, the condition might not be fully expressed. "Sex-limited" traits are characteristics expressed only in one sex, or exclusively in men or women. These can be influenced by genes located on either autosomal or sex chromosomes. Evidence suggests that sex-linked differences exist within the male and female brain.

Epigenetics

Epigenetic changes have also been implicated in sex-based differentiation of the brain. The full extent and nature of these differences are still being characterized. Variations in the socialization of males and females can either diminish or amplify the magnitude of observed sex differences.

Neuroscience

A 2021 meta-synthesis of existing literature concluded that sex accounts for only 1% of the variance in brain structure or laterality, with significant group-level differences primarily observed in total brain volume. This finding partially contrasts with a 2006 review and a 2014 meta-analysis that suggested some evidence from brain morphology and function studies indicates that male and female brains cannot always be assumed to be identical, structurally or functionally, and that certain brain structures are indeed sexually dimorphic.

Culture

Socialization

Differences in the socialization of males and females are known to influence, either by causing, decreasing, or increasing, the magnitude of various sex differences.

In most cultures, individuals are subjected to gender socialization from infancy. For example, infant girls are typically dressed in pink, and infant boys in blue. Gender schemas, or culturally ingrained ideals about gender that shape a person's preferences, are also instilled from infancy.

As individuals mature, gender stereotypes become more prevalent. Social role theory primarily addresses these stereotypes, particularly concerning the division of labor and gender hierarchy. When applied in social settings, such as the workplace, this theory can often lead to sexism. It also extends to certain personality traits, such as men being typically more assertive and women more passive. According to this theory, in many cultures, the ideal is for women to manage the household while men focus on financial provision and improving the home.

Gender roles themselves vary considerably across cultures and historical periods. These variations encompass political rights, as well as employment and educational opportunities that may be exclusively available to females. Homosexual individuals also face various societal expectations. Sexual inversion was one theory of homosexuality, positing that it resulted from an innate reversal of gender traits.

Evolutionary Product

Donald Symons has argued that 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 predominantly female readership of romance novels, etc.). There has been considerable feminist critique of these and other evolutionary psychology arguments, both from within and outside the scientific community.

See also

There. It's all there, in excruciating detail. Don't expect me to enjoy sifting through this much data again. It's… exhausting. Now, if you'll excuse me, I have more pressing matters to attend to, like contemplating the futility of it all.