The Uncomfortable Science Of Sex Differences - Steve Stewart-Williams

Evolutionary psychologists note that many sex differences appear early in life, persist across time (like mate and career preferences across the 20th century), and often appear despite cultural attempts to suppress them. This suggests an innate, unlearned contribution.

The gender equality paradox refers to the counterintuitive finding that in more gender-equal societies, sex differences (e.g., in career preferences) often become larger, not smaller. This contradicts social roles theory and patriarchy theory, which predict that more equality should reduce differences.

The largest psychological sex difference is in which sex each sex is primarily attracted to. The vast majority of men are primarily attracted to women, and vice versa. This seemingly obvious point is often overlooked but has a clear evolutionary rationale.

Parental investment is a major contributor to sex differences. Females generally invest more per offspring (pregnancy, nursing), limiting their maximum offspring number. This leads to males often evolving stronger drives for casual sex and sexual variety, as they can produce more offspring with minimal investment.

Men prioritize physical attractiveness due to its association with youthfulness and fertility, which is more critical for women's reproductive lifespan (post-menopause). Women prioritize resources and status because it signals a male's ability to provide and co-rear children, crucial for offspring survival.

In long-term relationships, women prioritize resources and status. However, in short-term, low-commitment relationships, women place as much, if not more, importance on physical attractiveness in men, as looks are a strong indicator of 'good genes' when there is no expectation of further investment.

Studies show that gay men tend to have more casual sex than straight men, while lesbians have less casual sex than straight women. This suggests that without the need to compromise with the typical sexual inclinations of the opposite sex, their behaviors offer a clearer view of underlying male and female sexual motivations.

Men are consistently more aggressive, especially for direct physical aggression. This difference escalates with intensity, with men perpetrating over 90% of homicides. This is linked to male-male competition for status and resources to increase mating opportunities.

There is no significant average sex difference in IQ or general cognitive ability. While there might be slight differences in specific abilities (e.g., women often better verbally, men in spatial tasks), and greater variance in men (more male geniuses and intellectual disabilities), overall cognitive abilities are more similar than different between sexes.

Testosterone has a direct biological cost to male lifespan. Historial data on eunuchs in the Korean Chosen Dynasty shows they lived longer than intact males of identical social standing, demonstrating that the hormone, while contributing to larger size, strength, and aggression, also shortens male life expectancy.

Minimizing sex differences can lead to overlooking distinct health symptoms in women (e.g., heart attacks, autism presentation) or creating "unisex straightjackets" that force people out of natural inclinations. Exaggerating them can push people into rigid gender roles, foster resentment (e.g., in workplace gaps), and lead to overlooking issues in the less-affected sex (e.g., male depression).