This article tests the effects of variables associated with political participation on the frequency of internal warfare. Findings suggest support for the hypothesis that democracies rarely fight each other.

The present study attempts to replicate the Ember, Ember, and Russett (1992) worldwide finding that fighting rarely occurs between democracies in a sample of eastern African societies. Following the earlier study, the authors considered internal warfare to be an analog of international warfare and measures of political participation analogous to democracy. The researchers also explore if there is an association between political participation and committing atrocities. Contrary to past findings, internal warfare was not predicted by the same set of variables as the 1992 study, but there is an inverse relationship between committing atrocities and political participation. However, when additional variables were added, internal warfare was significantly predicted by less political participation.

This paper reviews the results of the author's cross-cultural studies of war and aggression and their implications for prehistory.

This study examines the relationship between equality and democracy, focusing on social stratification and political participation as the primary measures. Results suggest that equality strengthens some aspects of democracy, but several other factors such as industrialization are involved in the relationship.

The present study investigates whether there is resilience variability following climate-related disasters in societies that are corporate-oriented, which promote participatory and inclusive structures, and exclusionary-oriented, which limit political authority and power. The findings offer modest support for social resilience theory that more flexible (i.e. more participatory) societies would be more resilient after a disaster than less flexible societies. Although only 5 of 14 correlations are significant, the direction is significant by a binomial sign test.

The author analyzes conditions that might favor social resilience during the Late Antique Little Ice Age (ca. 536-556 CE). The assumption is made that climatic conditions in the Northern Hemisphere during this period of time are very similar to those that would occur during a nuclear winter. These conditions include a drop in temperature and decreased solar radiation from volcanic eruptions. Measures for social resilience come from multiple variables for social change, which are tested against measures for type of political engagement. It is argued that broad political participation is correlated with resilience.

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 examines socio-economic predictors of political complexity. Findings suggest that class stratification is the most significant predictor of political complexity.

This article tests a series of hypotheses differentiating internal warfare and external warfare. Results support the theory that internal warfare is a population control mechanism more common in patrilocal societies, whereas external warfare occurs between two societies, one of which recently migrated and adopted matrilocal residence. Based on these findings, the authors assert that internal warfare can be regulated while external warfare cannot.

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.