This article reviews the theories on age-set systems and presents a cross-cultural test of Bernardi's theory regarding the development of age-sets as a response to a need for a system of integration in the context of frequent warfare. The findings do not support the hypothesis but rather point to the importance of changing group size and composition of local groups, as well as warfare, in predicting age-set systems.

This article reviews the theories on age-set systems and presents a cross-cultural test of Bernardi's theory regarding the development of age-sets as a response to a need for a system of integration in the context of frequent warfare. The findings do not support the hypothesis but rather point to the importance of changing group size and composition of local groups, as well as warfare, in predicting age-set systems.

This article reviews the theories on age-set systems and presents a cross-cultural test of Bernardi's theory regarding the development of age-sets as a response to a need for a system of integration in the context of frequent warfare. The findings do not support the hypothesis but rather point to the importance of changing group size and composition of local groups, as well as warfare, in predicting age-set systems.

"This paper describes how the "sex-ratio" explanation of polygyny compares with some alternative, supposedly causal explanations. The results suggest that polygyny is best predicted by two statistically independent factors--high male mortality in warfare…and delayed age of marriage for men."

"This paper describes how the "sex-ratio" explanation of polygyny compares with some alternative, supposedly causal explanations. The results suggest that polygyny is best predicted by two statistically independent factors--high male mortality in warfare…and delayed age of marriage for men."

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 study examines correlates of age-grading and generations, particularly bachelor promiscuity, in order to test the matched-pairs method of cross-cultural analysis. The authors suggest that their test is not a completely adequate measure of the matched-pairs method, but is merely a trial for using experimental and control groups in a cross-cultural study.

Using a new expert survey, the authors explore the democraticness of traditional political systems (TPS) in 159 ethnic groups in Africa. Their initial analysis finds that measures of public preference input and political process control are particularly strong contributors to the degree that a society may develop democracy in their TPS. They also find that societies with powerful elders are more likely to be democratic, while more hierarchically organized political systems and those with kings, chiefs, and segmentary lineages are less likely.

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 article tests some conditions that may lead to the emergence of unilineal descent, focusing on unilocality and warfare. Unilineal descent is thought to be likely in a unilocal society without a centralized political system that is experiencing intra- or inter-societal warfare. The authors also posit that a "clan" system usually develops prior to a "lineage" system.