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 explores predictors of variation in two dimensions of marital residence patterns among hunter-gatherers: 1) the tendency toward patrilocality versus matrilocality and 2) the tendency toward unilocality versus bilocality.

The present research investigates food sharing and labor sharing practices of 98 nonindustrial societies. The aims are to: 1) document the frequency and scope of sharing, and 2) test the theory that greater sharing is adaptive in societies subject to more resource stress (including natural hazards).

This study relates the type of games present in a society to the level of cultural complexity. Authors use a "game-type combination scale" that categorizes societies as having: 1) games of physical skill only; 2) games of physical skill and games of chance; and 3) games of physical skill, games of chance, and games of strategy. Results show a relationship between the game-type combination scale and indicators of cultural complexity.

This article considers the consequences of modernization. Factor analysis is used to identify four stages of modernization: 1) changes in education, government, and trade; 2) changes in health, technology, and transportation; 3) changes in family, religion, and toilet; and 4) changes in behavior. The authors then consider five trends they expect to be associated with modernization and test whether they develop over the course of the four stages. Results indicate that these 5 trends—increased cultural complexity, female status, pacification, suicide, and social stress—are associated with only the first and fourth stages.

This article investigates a cultural patterning of altered states of consciousness. The authors use an ordinal variable for a society's trance type; its four levels are 1) trance, 2) trance and possession trance, 3) possession trance, and 4) neither type. Results suggest that trance type is associated with measures of societal complexity and subsistence economy. Regional differences and the effects of diffusion are also examined.