Theories about the relationship between warfare, militarism, male dominance and authoritarianism are tested.

This paper examines the relationship of productive variation in land between ethnic groups to determine if an increased range of producible goods will increase trade, thus decreasing language diversity between neighboring groups. The author initially found that high-variation in land production lessened the diversity of language between ethnic groups in that area. To further test this correlation, the author found that high-productive variation increased trade and exogamous marriage and decreased inter-ethnic conflict. Based on these findings, the author suggests that neighboring ethnic languages co-evolved through the economic benefit of inter-ethnic trade and social interaction.

This article used sub-national, historical and cross-country data to examine if exposure to ultraviolet radiation (UV-R) could be a factor in the formation of individualism and collectivism. The study found support, across all data sets, that increased exposure to UV-R is associated to more collectivism within a culture. The authors theorized that UV-R exposure increases the likelihood of eye disease causing higher rates of blindness. With increased levels of blindness, the more emphasis there will be on close family relations and/or increased uncertainty avoidance from out-groups leading to more collectivism in a culture.

In this study, the authors examine pathways to social inequality, specifically social class hierarchy, in 408 non-industrial societies. In a path model, they find social class hierarchy to be directly associated with increased population size, intensive agriculture and large animal husbandry, real property inheritance (unigeniture) and hereditary political succession, with an overall R-squared of 0.45. They conclude that a complex web of effects consisting of environmental variables, mediated by resource intensification, wealth transmission variables, and population size all shape social inequality.

This article refines previous research on marriage transactions and offers descriptions of new types of marriage transactions. First, the authors examine the frequency and distribution of marriage transactions. Second,the authors use a bio-cultural approach to examine how differences in male and female reproductive strategies and the kin selection theory are associated with marriage transactions.

Using an evolutionary perspective, this study tests hypotheses relating gender and kinship roles to the amount of direct and indirect care provided during and around childbirth. The roles of paternal certainty, residence rules and descent groups are also examined.

The effect of female status on women's mate preference in a sample of nonindustrial societies is examined.

This study examines ecological, social, and psychological theories for men's fear of heterosexual sex in a cross-cultural sample. Findings support the hypotheses and a causal model is presented.

This paper suggests a tentative analysis of continuous female sexual receptivity based on a random sample of mammals and birds. It is suggested that humans developed continuous female sexual receptivity because humans have the unusual combination of long infant dependency, group living, and male-female bonding.

This study examines differences in the ease of socialization for male and female children in preindustrial societies. Results support the hypothesis that the socialization of females is accomplished more easily than the socialization of males.