This article tests four hypotheses regarding scarification, which is described as 1) a rite of passage, 2) a hardening/trauma procedure, 3) a nonadaptive sexually selected character, or 4) an adaptive pathogen driven sexually selected character. Only the third hypothesis is supported in a worldwide sample, suggesting that scarification is associated with polygyny. The other three are each supported in different regional subsamples—principally the first hypothesis (supported in Africa, the Insular Pacific, and South America).

This study focuses on the relationship between pathogen prevalence and mate selection. Results show that increased pathogen prevalence is significantly associated with an increased importance in the physical attractiveness of potential mates.

This study is a comprehensive analysis of female and male genital mutilation/cutting (FGM/C and MGM/C) practices, including their history and socio-ecological correlates, using a phylogenetic cross-cultural framework. It employed two global ethnographic samples, the Ethnographic Atlas (EA) and the Standard Cross-Cultural Sample (SCCS), and two subsets of the phylogeny (supertree) of human populations based on genetic and linguistic data, to investigate the variables that may have led to the introduction of these practices, and to determine where and when they may have originated. The study suggests that MGM/C probably originated in polygynous societies with separate residence for co-wives, supporting a mate-guarding function, and that FGM/C likely originated subsequently and almost exclusively in societies already practicing MGM/C, where it may have become a signal of chastity. Both practices are believed to have originated multiple times, some as early as in the mid-Holocene (5,000–7,000 years ago). The study posits that GM/C co-evolves with and may help maintain fundamental social structures and that the high fitness costs of FGM/C are offset by social benefits, such as enhanced marriageability and social capital.

This study tests the association between pathogen risk and degree of polygyny and sexual advertisement. Results show that the greater the risk of serious pathogens, the greater the degree of polygyny. The correlation between pathogen risk and sexual signals is only marginally significant. An association between mate choice and resource control is also examined.

Focusing on 61 preindustrial societies that have information on fertility, the author asks what factors may explain variation in fertility, what devices are used to control fertility, and whether differences in fertility appear to be in line with the societies' environments.

The goal of the paper is to demonstrate how international slave trade spread the institution of slavery throughout Africa, resulting in long-term effects of the continent’s income and political centralization. The author first estimated the travel time to slave ports from each society in the Ethnographic Atlas to determine predicting factors for the adoption of slave trade in African societies. The author reported that societies with high exposure to slave capture in the past were more likely to have the custom of slavery and the custom of polygyny. The author further suggested that slavery institutions emerged in West Africa through local, politically centralized aristocratic systems while emerging in East Africa through the preservation of wealth within the nuclear family over generations.

This article tests several hypotheses related to the presence or absence of polygyny. Results suggest a negative relationship between polygyny and male provisioning, and positive relationships between polygyny and warfare, interpersonal aggression, and pathogen stress.

The second and third parts of this book classify the economic systems of foraging and agricultural societies in the SCCS based on correlations between their institutions of property an distribution. These economic types are then examined for relationships with other social, political, demographic, and environmental factors in order to draw tentative conclusions regarding the origins of the Agricultural and Industrial Revolutions. The fourth part of the book uses cross-national data to examine similar associations in industrial/service economies, and is not included here.

This article uses logistic regression analysis to examine pathogen stress and male mortality in warfare as predictors of nonsororal polygyny. Differences between state and non-state societies are observed. The authors also retest variables from White and Burton's 1988 study on causes of polygyny, finding only fraternal interest groups and absence of plow significant.

This article presents two evolutionary models that may explain relationships between war and socialization of children: the "environmentally contingent reproductive strategy" (ECRS) model put forward by Draper and Harpending (1982), and a model put forward by Carol and Melvin Ember. Results do not provide support for the hypotheses involving father-infant sleeping proximity derived from the ECRS model. The authors also find some inconsistencies with their own model.