In this paper, the author argues that moral systems evolved as a way to enforce cooperation between people outside of kin groups. Because cooperation within kin groups has apparent adaptive advantages, it is argued that these moral systems will be less important for societies with tight kin groups and conversely more important for those with looser kin groups. In order to test this theory, the author creates an original model that incorporates both ethnographic data and data from contemporary countries. Thus, it is postulated that historical kinship practices will influence contemporary systems. The paper concludes that there is sufficient historical evidence for this theory.

Does belief in moralizing and punitive gods promote sociality between coreligionists who are otherwise strangers? A recent dataset of behavioral economic experiment results and demographic and religious data among eight disparate populations allows the researchers to test their hypothesis of a positive association between deity's perceived interest in human morality and favorability of treatment of outsiders who share a religion. Their findings mostly support this hypothesis, which they suggest lends credibility to a theory in which religion encourages cooperation between large groups of people, and is thus a successful product of cultural evolution.

This article is a quantitative analysis of 592 participants from 8 societies. The study examines a number of theories about what predicts moralistic religions, including life history theory. Findings suggest that there is no evident relationship between these life history predictions and the religious beliefs regarding moralism.

Researchers tested the popular identity fusion theory, which states that while maintaining one’s own individual identity, a deep affinity with one’s group can contribute to sacrifice for that group, in conjunction with their own hypotheses, using a behavior economic experiment. The experiment looked at whether after rolling a die to determine which cup a coin was placed into, participants actually followed the rules, or favored themselves (by putting the coin into their own cups at a disproportionate rate). The findings state that while on average, the individual participants did indeed favor themselves, those with higher ingroup fusion were more likely to sacrifice coins to other members of their ‘ingroup.' The experiments were conducted in 8 culturally diverse field sites.

In this study, the authors inspect the relationship between religion, morality, and cooperation by examining the extent to which people associate their deities with moral concern. Using data from 2,228 individuals in 15 different field sites, they find that on average, people tend to ascribe at least some moral concern to their deities, and this effect is stable even after controlling for the influence of explicitly moralistic deities that these societies also worship. The authors also find that ratings of moral concern are not necessarily very high, even for deities that are typically considered to be moralistic, and that there is individual-level variation in the degree of moral concern attributed to deities. In addition, there is an individual-level correlation between how morally interested two selected deities are conceived to be and that being male or more educated decreases the likelihood of associating deities with moral concern. These findings challenge the longstanding belief that belief in moralistic deities is unique to certain societies or religions and instead suggest that the association between deities and moral concern is more widespread and variable, and suggest that the moral character of gods may be tied to cooperation within societies.

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 article examines the conditions under which slavery occurs in preindustrial societies. Results suggest that social stratification and the existence of open resources are both necessary conditions for the occurrence of slavery.

"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 article tests the assumption that foragers are more likely to experience regular and severe food shortages than sedentary agriculturalists. The results indicate that there is no statistical difference in the quantity of available food or the frequency or extent of food shortages between preindustrial foragers, recent foragers, and agriculturalists.

This article examines predictors of intimacy between husbands and wives. Emphasis is on equality of spouses. A causal model is presented.