This article examines the evolution of games, particularly the way the complexity of games is affected by political organization, demographics, social differentiation, and religious differentiation.

"Seven of Max Weber's ideal-typical specifications for 'rational bureaucracy' are reformulated as a system of three 'bureaucratic' and four 'rational' variables. It is proposed that (a) bureaucratic variables are positively associated; (b) rational variables are positively associated; but that (c) rational variables are negatively associated with bureaucratic variables." Hypotheses are supported.

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.

Authors Michael Burton and Douglas White present and test an ecological model for the process of agricultural intensification that aims to explain variance in (and the reduction in) female contribution to agriculture. The model synthesizes and expands upon findings put forth by previous studies in order to create a more comprehensive design. Results suggest that the strongest predictors of female contribution to agriculture are the number of dry months, the importance of domesticated animals to subsistence, and the use of the plow in farming. Crop type, although a weaker predictor, is also supported.

This study seeks to examine the influence that UV radiation and climate might have on gender inequality, and tests two extant theories on why gender inequality exists -- the life-history theory (aligned with climate) and the cognitive performance theory (aligned with UV radiation). The model with UV radiation as the main predictor fits the data on gender inequality the best, and pathogen prevalence and the ACP1*B allele were also found to be associated with gender inequality. The model was found to be robust across continents and ancestry. The study also highlights the need for further research to better understand the complex interplay of these factors in different cultures.

This study proposes that extended family households are more common when a mother or father in a one-family household cannot meet activity requirements. Empirical analysis suggests that this trend occurs in both agricultural and non-agricultural societies.

This study presents a log linear analysis of the relationship between plow agriculture, female crop tending, and polygyny. The hypothesis was not supported.

This study presents a model of sexual division of labor using entailment analysis that accounts for distance of the task away from home and danger of the task. Results support the notion that childbirth and nursing are the main constraints on the sexual division of labor and that men tend to be allocated tasks that are more distant and dangerous.

This study advances the status envy hypothesis of sex identification to explain customs such as male initiation ceremonies and the couvade. Theory of sex identification is discussed; resource withholding, exclusive mother-child sleeping, patrilocality, father absence, female status, and initiation are all considered. Hypotheses are supported with empirical tests.

In an effort to better understand variation in jealous response cross-culturally, the researchers of this study surveyed 11 different populations, eight of which were small-scale societies on five different continents (Mayangna, Shuar, Tsimane, Himba, Hadza, Karo Batak, Mosuo, and Yasawa) and three of which were in urban settings (Los Angeles, CA, "urban India" (online), and Okinawa, Japan). Looking at the differences between sexual and emotional infidelity, researchers found that greater paternal investment and lower frequency of extramarital sex are associated with more severe jealous response.