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.

This article identifies several methodological errors in the original study or moralizing gods by Roes and Raymond (2003) and presents new multiple regression model. Results suggest that a belief in moralizing gods is spread though cultural transmission, but it is also associated with conditions such as lower agricultural potential and lower external warfare. The authors theorize that moralizing gods have functional purposes such as bolstering property rights or maintaining social hierarchy.

Authors contend that many of the differences across the 50 states can be attributed to the degree to which social entities are "tight" (have many strongly enforced rules and little tolerance to deviance) or "loose" (have few strongly enforced rules and greater tolerance for deviance). Significant correlations were found between many state characteristics and tightness-looseness.

This article employs cross-national and cross-cultural methods to investigate whether pathogen stress is a direct determinant of authoritarianism. The study controls on other factors such as famine, warfare, and malnutrition and evaluates alternative causal models.

This article investigates relationships among society size, war and conflict, preferred habitats, and belief in moralizing gods. The authors discuss morality and collective action in the face of natural disasters and competition for resources, theorizing that beliefs in moralizing gods could facilitate such cooperation.

This article explores differences between "tight" cultures ("have many strong norms and low tolerance of deviant behavior") and "loose" cultures ("have weak social norms and high tolerance of deviant behavior"). The tightness-looseness measure manifests in a myriad of macro and micro phenomena, from governance and religiosity to individual psychological processes. This study investigates these phenomena in modern nations rather than traditional societies. Potential ecological, historical, and socio-political predictors of tightness-looseness are also examined.

The article tests theories that may explain why warfare frequency varies from society to society. The focus is on ecological problems, particularly different kinds of resource scarcity, but social and psychological theories are also tested with both bivariate and multivariate analyses. Because unpredictable disasters are such a strong predictor in nonstate societies, the authors theorize that war may mostly be caused by a fear of nature.

The author builds upon previous research (Winkelman 1998) to further elucidate the cross-cultural predictors of institutionalized human sacrifice. The author considers a range of ecological factors and political variables, particularly geopolitical dynamics and intra- and inter-group relations. Other factors were explored, including social complexity and social structures. The author identifies the lack of an effective superordinate political authority as a main determinant in similar behaviors contemporarily (e.g. suicide bombers, beheadings, public brutality in civil war).

This article draws from previous research by Ember and Ember (1992) that suggests a relationship between socialization for mistrust in others, unpredictable natural disasters, and warfare frequency. Authors hypothesize that the inclusion of a corporate-network strategy variable will improve the predictive power of the Embers' model for warfare. Results support this hypothesis.

The authors of this study explore the relationship between climate variability and beliefs that high gods are associated with the weather. As predicted, they find significant correlations between these beliefs and dry climates. They then evaluate how these findings contribute to their previous understanding of resource stress and its association to beliefs in high gods.