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 article suggests a general theory of conflict and violence that may help explain the conditions under which internal conflict co-occur or are differentiated.

The dissertation in its entirety is an archaeological investigation of population aggregation among the Mesa Verde region Anasazi A.D. 900-1300. Chapters four and five of Adlers larger work focus on cross-cultural perspectives to inform discussion around resource access and community strength. Multiple different hypotheses were tested with different data sets, but the HRAF database and Standard Cross Cultural Sample were used throughout.

In this study, the author empirically tests a formulation of Ellen Dissanayake's evolutionary theory of art, which argues that art evolved to promote group cohesion. The hypotheses derived from this theory and tested in this study specifically focus on ritual art and its relationships to various proxies for group cohesion such as community conflict and internal warfare. Results show that the presence of ritual art is significantly higher where certain measures of group cohesion are also higher (including lower internal warfare, lower conflict between communities of the same society, and lower frequency of violent conflict between groups within local communities).

This study investigates the presence of feuding, arguing that a solely evolutionary or functional approach misses important inter-societal factors. Results indicate that while fraternal interest groups are associated with feuding, the presence of war and level of political integration also increase the likelihood of feuding.

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.

This article investigates whether external warfare, intercommunity trade, and female exogamy lead to more amicable intercommunity relationships. Intercommunity amicability is considered a historical facilitator of the large-scale integration of human groups. The absence of internal warfare is used as a measure for intercommunity amicability.

This study examines pairwise differences between similar cultures in order to minimize cultural variation within the SCCS and reveal possible correlates of cultural complexity. Results suggest that one measure of complexity (government above the community level) is significantly associated with several other variables.

This book examines the characteristics of warlike and warless foraging societies, as well as the transitional stages that occur when a society becomes warlike. Several predicted correlates of warfare frequency are supported.

This article answers questions raised by Abrahamson (1969) about the relationship between warfare and political complexity. Significant correlations were found between political complexity and the frequency of being attacked and between frequency of attacking and military success.