In this article, the author argues that matrilocality is a form of social organization that is conducive to expansion in tribal societies with smaller populations. Because this organization increases internal solidarity and success in external warfare, the theory suggests that it is best suited for expansion on cultural frontiers by groups with small populations. The author supports this theory with empirical tests on 33 societies and case studies of Bantu and Austronesian expansion.

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.

This paper poses and tests relationships between local spatial variability of rainfall and property rights, as well as the degree of hierarchy, across 41 different tribal societies in Sudan. The authors find that there is a significant negative relationship between rainfall variability and degree of hierarchy. They also find that in the presence of local rainfall variability in Sudan, members of a tribe are more likely to establish common property institutions that allow access to all members.

This study of initiation rites focuses on the hidden and explicit education that takes place in the course of public initiation rites and induction into secret societies. The author suggests that in tribal societies, initiations reinforce egalitarianism while in chiefdoms secret societies reinforce differentiation. Deviant cases were also analyzed.

Why did headhunting- the practice of taking human heads for ritualistic reasons- emerge in many societies? Through phylogenetic comparative analyses of Austronesian societies, the authors find that headhunting developed as a cultural response to frequent inter-tribal conflict and warfare. When warfare declined, the frequency of headhunting did as well.

This paper tests "theories which suggest that there are causal-functional relationships between the dependent variables peacemaking and peace stability on the one hand and certain independent variables, such as political complexity, warrior class, warfare objectives, cultural homology and intersocietal ties, on the other hand." Significant relationships were found between the last three independent variables.

Using Bayesian phylogenetic analysis, the authors ask: "Do cultural traits exhibit different histories of transmission?". They explore two competing models regarding Iranian tribal textile tradition. First, the "hierarchically integrated system hypothesis" emphasizes the importance of a core tradition and peripheral traits that are shared among contemporaneous populations. Second, the "multiple coherent units hypothesis" suggests that the groups of cultural traits have different transmission histories. The results show more support towards the "multiple coherent units hypothesis", specifically that pile-weave designs emerge as a cultural unit with a unique phylogenetic history compared to other textile characters.

Using homicide rates as an indicator, this article examines the ecological factors that might be functioning as stressors in the environment of thirty-four East African tribes. A series of hypotheses dealing with the relationships between these stressors and tribal levels of aggressiveness are tested.

The author explicitly defines and provides code for male and female age organizations and secret societies in Africa, as well as their significant sociopolitical roles within society. The author conducts preliminary analysis using the codes to explore characteristics and regional patterns of such organizations and societies. The analysis is compared to existing studies in order to assess the code and better understand cross-cultural patterns and variances. The author identifies the usefulness of the code beyond Africa, and discusses avenues for future research. No explicit hypotheses were tested, but Ericksen includes some descriptive generalizations.

This study offers a preliminary exploration into the relationships between demography and childcare. Most of the hypotheses presented in this paper are are not formally tested, but are examined using previous research. These hypotheses should be used to inform future research. One hypothesis tested using limited data found that male biased sex ratios are likely to exist in societies where males contribute more calories to the diet than females.