Fighting ability, although recognized as fundamental to intrasexual competition in many nonhuman species, has received little attention as an explanatory variable in the social sciences. Multiple lines of evidence from archaeology, criminology, anthropology, physiology, and psychology suggest that fighting ability was a crucial aspect of intrasexual competition for ancestral human males, and this has contributed to the evolution of numerous physical and psychological sex differences. Because fighting ability was relevant to many domains of interaction, male psychology should have evolved such (...) that a man’s attitudes and behavioral responses are calibrated according to his formidability. Data are reviewed showing that better fighters feel entitled to better outcomes, set lower thresholds for anger/aggression, have self-favoring political attitudes, and believe more in the utility of warfare. New data are presented showing that among Hollywood actors, those selected for their physical strength (i.e., action stars) are more likely to believe in the utility of warfare. (shrink)

Sex differences in physical and indirect aggression have been found in many societies but, to our knowledge, have not been studied in a population of hunter-gatherers. Among Aka foragers of the Central African Republic we tested whether males physically aggressed more than females, and whether females indirectly aggressed more than males, as has been seen in other societies. We also tested predictions of an evolutionary theory of physical strength, anger, and physical aggression. We found a large male bias in physical (...) aggression. Controlling for anger, we found an adult female bias in indirect aggression. Physical strength predicted anger, which predicted hitting, although results were sensitive to the inclusion or exclusion of traditional healers, who were physically and emotionally distinct from other Aka. With some important caveats, our results generally support the predicted sex differences in physical aggression and indirect aggression, and the predicted relationships among anger, strength, and aggression. (shrink)

McCullough et al. present a compelling case that anger-based revenge is designed to disincentivize the target from imposing costs on the vengeful individual. Here I present a contrast between revenge motivated by anger and revenge motivated by hatred, which remains largely unexplored in the literature.

At the heart of the debate between social role theorists and evolutionary psychologists is whether natural selection has designed the minds of the sexes differently to some interesting extent. In this commentary I describe the standards of evidence for both the positive and negative claims. In my opinion, Archer has met the standard for designed sex differences in intrasexual conflict.