The article examines whether cultural groups tend to use supernatural beliefs more to explain natural phenomena or social phenomena. Analysis of ethnographic text from 114 diverse societies reveals that supernatural explanations are more common for natural phenomena, consistent with the theory that humans tend to perceive intent and agency in the natural world. However, supernatural explanations of social phenomena were more prevalent in urbanized societies with greater social complexity and anonymity. The study highlights how people use supernatural beliefs to explain their world and how this varies across small-scale and urbanized communities.

The ability of adults to digest lactose is common only in populations of European and circum-Mediterranean origin, a distribution thought to be a result of genetic adaptation to drinking milk from domestic livestock. Two additional hypotheses have been proposed to explain the distribution of high lactose digestion capacity: (1) supplemental calcium in high-latitude populations prone to vitamin D deficiency and (2) maintenance of water and electrolytes in the body in highly arid environments. However, these hypotheses are confounded by the shared ancestry of populations whose lactose digestion capability has been tested. Therefore, the authors test all three hypotheses using a phylogenetic comparative method for 62 cultures.

This article tests various explainations for corporal punishment of children, including social complexity, a societal culture of violence, and whether help in child rearing is available. Analysis suggests that corporal punishment may be a parent's way to prepare children for societal power inequality.