This paper reviews the results of the author's cross-cultural studies of war and aggression and their implications for prehistory.

This study explores several correlates of interpersonal violence. Multiple regression analysis suggests that socialization for aggression in boys in late childhood is the strongest predictor of higher rates of homicide and assault. Path analysis suggests that socialization for aggression is a consequence, not a cause, of war.

This paper presents empirical tests of two theories put forth to explain violence toward women. The first predicts that warfare promotes socialization for aggression and legitimizes violence toward women, while the second predicts that violence works as a way to control potential for female infidelity. An association is found between high male-to-female sex ratio and violence towards women, suggesting support for the second theory over the first, which is consistent with more narrowly-focused studies by Avakame (1999), Bose et al. (2013), and D'Alessio & Stolzenberg (2010).

This article examines the phenomenon of hypermasculine behavior and a masculine ideology cross-culturally to determine to what degree socialization stimulates this aggressive behavior in some groups and not others.

A general theory of conflict and violence provides a framework for understanding the relationship between internal and external political conflict and the conditions under which they are connected. This study draws on a cross-cultural sample of 90 preindustrial societies, assessing whether these two forms of conflict covary and identifies the social factors that shape their associations. Using a multiple regression analysis reveals a moderate positive relationship overall, but the strength and nature of these relationships depend on specific societal characteristics. Societies in which internal and external conflict can occur and fall together display remarkedly different patterns of cross-cutting ties compared to those in which the two forms operate independently. Structural features of social organization emerge as key determinants of whether aggression is directed inward, outward, or both. In contrast, dispositional (psychocultural) traits are strong predictors of overall conflict levels but do not distinguish between internal and external targets. Together, these findings showcases the importance of integrating structural and dispositional factors in explaining patterns of political violence.

The article tests theories that may explain why warfare frequency varies from society to society. The focus is on ecological problems, particularly different kinds of resource scarcity, but social and psychological theories are also tested with both bivariate and multivariate analyses. Because unpredictable disasters are such a strong predictor in nonstate societies, the authors theorize that war may mostly be caused by a fear of nature.

Using a sample of 80 countries and political regions, the present study examines the effect parasite stress has on people's trust towards ingroup and outgroup members. The findings do not offer support of there being a concave relationship between parasite stress and ingroup member trust. The results do indicate that there is a U-correlation between trusting outgroup members and parasite stress.

This paper supports Beatrice B. Whiting's (1965) sex-identity conflict hypothesis which suggests a relationship between males' early identification with their mothers and male violence. Authors find that, in addition to socialization aggression, frequency of homicide/assault is significantly related to father-infant sleeping distance, particularly when residence is not matrilocal and/or warfare is more than occasional.

Using a sample of 145 African societies, the authors seek to examine the relationship between segmentary lineage organization and conflict. Presented is evidence supporting the claim that segmentary lineage societies are more prone to conflict and to conflicts larger in scale and duration. The authors aim to contribute to a better understanding of the determinants of conflict, and additionally address the applicability of the present study beyond Africa.

In this article, the authors seek to understand dog-human coevolution by considering predictors of different aspects of dog-human relationships across cultures. In order to measure dog-human relationships, the researchers created three indexes: dogs' utility for humans (DUH), humans' utility for dogs (HUD), and the personhood of dogs (PD). Each of these indexes were tested against various pre-coded variables that were empirically and theoretically relevant to this subject.