Using a sample of 145 African societies, the authors seek to examine the relationship between segmentary lineage organization and conflict. Presented is evidence supporting the claim that segmentary lineage societies are more prone to conflict and to conflicts larger in scale and duration. The authors aim to contribute to a better understanding of the determinants of conflict, and additionally address the applicability of the present study beyond Africa.

Using a new measure called "territorial fractionalization" to indicate the extent to which traditional societies are split across current states, the authors of this study propose that fragmentation of ethnic groups and ethnonationalism is key to understanding civil conflict. They find that higher measures of territorial fractionalization significantly predict a higher risk of civil conflict, and that greater increases in territorial fractionalization also predict greater risk of civil conflict. These results hold for a global sample of data from 1945 to 2017, as well as in European and African subsamples dating back to 1886.

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.

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 echnology and higher population density predict war, and that overall ecological-evolutionary and sociopolitical explanations of war are equally supported by empirical data.

The author builds upon previous research (Winkelman 1998) to further elucidate the cross-cultural predictors of institutionalized human sacrifice. The author considers a range of ecological factors and political variables, particularly geopolitical dynamics and intra- and inter-group relations. Other factors were explored, including social complexity and social structures. The author identifies the lack of an effective superordinate political authority as a main determinant in similar behaviors contemporarily (e.g. suicide bombers, beheadings, public brutality in civil war).

This book examines the difference between warless and warlike societies and attempts to determine the point at which a society becomes warlike. The author suggests that differences between warless and warlike societies are mostly organizational and hypothesizes that "unsegmented" societies, or societies that have a weaker sense of group identity and cohesion, will be more likely to be warless than "segmented" societies. Several tests are presented. Results generally support the hypothesis.

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 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 study is based on data given in Quincy Wright's (1942) 'A Study of War.' The author examines many correlates of belligerence in non-industrial societies. Results suggest that political organization, inter-cultural relations, and level of primitivity are associated with belligerence.

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.