Inductivist

Past research indicates that men are more physically aggressive than women, but very little research has examined mediators of this gender difference. Indeed, the only established finding to date is that one plausible mediator – namely trait anger – shows no reliable gender difference whatsoever. Drawing on sexual selection theory and social-learning theories, we predicted that revenge may mediate this gender difference even though anger does not. Three studies using both personality questionnaires (Studies 1 and 2) and objective laboratory measures of aggression (Study 3) provided support for this contention. The results provide some of the first evidence for a reliable mediator of gender difference in physical aggression.

Sexual selection theory is the most prominent evolutionary explanation of gender differences in physical aggression. According to this theory, men are typically under greater evolutionary pressures to behave aggressively than women. Because women are sometimes unavailable for reproduction due to pregnancy, women are argued to be a more valuable reproductive resource for which men must compete. Men can do so by aggressively excluding other men from mating opportunities or by seeking to attract women. Evolutionary theorists have traditionally argued that men mainly seek to attract women by establishing a more dominant position in the social hierarchy.

According to Daly and Wilson, these factors have converged and made men more prone to aggressive retaliation in the face of minor provocations. In order to deter male rivals from aggression and to achieve a dominant status, men need to establish a reputation for “toughness” (i.e., that they are not vulnerable to mistreatment by others). Thus, even minor insults demand swift and forceful retaliation.

Consistent with this, crime statistics and laboratory experiments have both shown that men are more likely to respond to trivial provocations with extreme retaliation. A large proportion of murders can be attributed to men responding to minor provocations, but similar incidences are exceedingly rare among women and. Moreover, laboratory experiments show that priming status goals leads men (but not women) to be more physically aggressive in the face of minor provocations.

Pigmentation of the hair, skin, cuticle, feather and eye is one of the most salient and variable attributes of vertebrates. In many species, melanin-based coloration is found to be pleiotropically linked to behavior. We review animal studies that have found darker pigmented individuals average higher amounts of aggression and sexual activity than lighter pigmented individuals. We hypothesize that similar relationships between pigmentation, aggression, and sexuality occur in humans. We first review the literature on non-human animals and then review some of the correlates of melanin in people, including aggression and sexual activity. Both within human populations (e.g., siblings), and between populations (e.g., races, nations, states), studies find that darker pigmented people average higher levels of aggression and sexual activity (and also lower IQ). We conceptualize skin color as a multigenerational adaptation to differences in climate over the last 70,000 years as a result of “cold winters theory” and the “Out-of-Africa” model of human origins. We propose life history theory to explain the covariation found between human (and non-human) pigmentation and variables such as birth rate, infant mortality, longevity, rate of HIV/AIDS, and violent crime.