This study examines how social structure, political organization, and intersocietal relations may affect the incidence of internal warfare (between culturally similar political communities). Results show that in uncentralized political systems, fraternal interest groups and unauthorized raiding parties may increase the incidence of internal war.

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 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.

This study examines two theories concerning the prevalence of rape: deterrence theory and fraternal interest group theory. Results indicate that both punishment and fraternal interest groups influence the frequency of rape, though neither variable is a necessary cause. The effects of marital residence and polygyny are also considered.

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 examines the relationship between political system and practices of killing captured enemies. Concludes that political systems (some simpler and some more complex) relying on terror tend to kill all enemies.

The author presents a comprehensive study on the prevalence, presentation, and motivation of the "ultimate coercive sanction": capital punishment, or the "death penalty". He begins by examining capital punishment across all 53 cultures for which data was present in the Probability Sample Files, and finds that capital punishment is overwhelmingly present. After discerning some general trends, the author examines how capital punishment presents itself across different kinds of political systems, and uses the results to voice support for various theories on why the capital punishment is practiced. The study concludes by stating that the capital punishment may be something that human society may never be truly rid of, but greater societal stability may be able to reduce its prevalence.