This study examines the relationship between group exogamy and peace. None of the hypotheses were supported.

This study tests a common theory that predicts a positive relationship between exogamy and cross-allegiances between social units. Results did not support this prediction. Cross-allegiances were only weakly related to cross-cousin marriage.

This article tests the conflicting loyalties theory that predicts feuding will be absent when multiple allegiances are present. The author tests this theory using variables that are believed to establish cross-cutting loyalties, such as exogamy and cousin marriage. Several hypotheses are tested, none are supported.

This article offers a critique of the study by Divale and Harris (1976).

This article examines possible environmental predictors of ethnic diversity around the world. Results suggest that global ethnic diversity is associated with latitude, habitat diversity, pathogen stress, and climate.

This article investigates how pathogen risk affects xenophobia, in-group bias, and collectivist and conformist values. Data analysis suggests that there is an association between pathogen risk and socialization for collectivist values, but the other variables were not associated with pathogen prevalence.

In this study, the authors explore the presence of disagreement between parents and their children over choice in spouse as an extension of theories regarding the evolution of mate choice. In non-human animal studies, free mate choice is generally associated with higher fitness. Thus mate preferences, in humans and non-human animals, may have evolved to improve fitness in comparison to random mating. Arranged marriages might likewise reduce biological fitness if parents choose a different spouse than their children would choose. Using ethnographic data from 119 societies, the authors assess the degree to which parents and offspring disagree on mate choice. In about 85% of the cases examined, parents disagreed with offspring choice. The authors call for explicit research on fitness outcomes when disagreement occurs.

This paper investigates ritual related to the female reproductive cycle. The author examines two types of ritual female pollution-avoidance ritual. meant to differentiate sex roles in a society, and male ritual (including couvade) associated with the female reproductive cycle, meant to minimize sex differentiation. Empirical analysis reveals several societal characteristics associated with each of these two types of ritual, suggesting that ritual can be used to encourage sex role rigidity or flexibility.

This paper examines ritual surrounding the female reproductive cycle and its relationship with female power. Data support two patterns: female pollution ritual tends to take place in relatively complex societies with low female contribution to subsistence, low female status, unilineal kinship and extended families; male productive ritual, on the other hand, tends to take place in societies with higher female contribution to subsistence, higher female status, cognatic kinship and small families.

The preindustrial family structure instilled family members with values that passed through generations and impact today's political attitudes and policies. Three studies show that ancestral kinship structure predicts right-wing cultural attitudes and, among those less engaged in politics, left-wing economic attitudes (though controlling for the country of residence removes this prediction). Stronger country-level ancestral kinship strength also increases anti-LGBT policies and welfare spending. This work indicates that political beliefs are rooted in the value systems and familial institutions created by our forebears.