In this article, the authors seek to reevaluate Nolan's (2003) study on the primary determinants of war. They reanalyze his hypotheses with what they claim are more robust measures and methodology. They conclude that there is only a little evidence supporting Nolan's theories, that more productive technology and higher population density predict war, and that overall ecological-evolutionary and sociopolitical explanations of war are equally supported by empirical data.

This article investigates commonly accepted theories that purport to explain political centralization and investigate their relevance to sub-Saharan Africa. The leading ideas for the formation of political centralization using a worldwide sample include population density, inter-state warfare, and trade. However, the authors reported these factors are not predictive of the sub-Saharan Africa sample. The authors suggest that the lack of agricultural productivity in sub-Saharan Africa may have stunted population density therefore inhibiting political centralization and that Africa’s poor economic performance is, in part, due to lack of political centralization.

This book takes a cross-cultural, cross-historical approach to the study of military deterrence. Political, economic, and geographic correlates are considered, particularly military and diplomatic strategy. Several hypotheses are tested and some are supported.

This book investigates the evolution of military organizations and their activities. Hypotheses frequently relate military organizations to political variables. Data suggested that more politically centralized societies have more sophisticated military organizations which are more likely to be successful in conflict (though military sophistication does not appear to deter attack).

This study tests an adaptational theory of military organization. Test of the relationship between population, residence type and military organization are presented; findings support the hypotheses.

This article examines the relationship between warfare and trade and concludes that the relationship varies within different levels of political organization.

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.

Using a self selected sample of 33 ex British colonies and the Ethnic Power Relations database, the author sampled 170 ethnic groups from Africa, Asia, and the Middle East to test for association between precolonial state formation, colonial state building tactics, and modern ethnic conflicts. The author theorized that ethnic groups that were centrally governed before the colonial period were less likely to be recruited to colonial security forces, leaving them out of the picture during the formation of the independence movement and the formation of a post-colonial regime. This in turn is theorized to lead to greater contemporary armed conflict against the regime from which they were excluded.

The authors construct a mathematical model from which they generate their main hypothesis that resource unpredictability should be associated with frequency of warfare. A cross-cultural test of this hypothesis was performed by Ember and Ember (1992). The authors critique these findings for state societies and test and alternate hypothesis for application to state societies.

This study asserts that the structure of work organizations is affected more by production techniques than societal complexity. Empirical analysis suggests two trends: 1) production techniques that increase the importance of workers will influence rationality in work organizations, and 2) production techniques that increase the importance of workers and societal complexity will affect the bureaucratic elements of work organizations approximately equally. These findings challenge Udy’s (1970) thesis that complex peasant societies face more challenges than less complex societies in transitioning to modern industrial work forms.