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 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).

In this article, the authors explore cultural variables that they propose contribute to the maintenance of peace in non-warring societies. These variables are compared in 16 peaceful systems (as coded by the authors from anthropological and historical data) and in 30 warring societies taken from the Standard Cross-Cultural Sample (SCCS). Findings associate more peaceful cultures with peace systems, and non-peaceful cultures with warring societies.

This paper seeks to understand how the conflict resolution strategies of indigenous and non-indigenous groups differ in their efficacy. The authors suggest that indigenous methods of conflict resolution are more effective than non-indigenous methods by demonstrating that subjects from the Outline of Cultural Materials (OCM) associated with indigenous conflict management (ICM) will co-occur less frequently with OCM terms related to conflict than subjects related to non-ICM. They tested this by selecting OCM subjects that they felt best represented ICM, non-ICM, and instances of conflict and using chi-square tests to show how often these subjects co-occurred. They subsequently split up the "conflict" variable into four forms of conflict in order to show whether any of these forms might be more frequently found associated with ICM or non-ICM subjects. The results showed that conflict subjects were more likely to co-occur with non-ICM subjects, and that sociocultural/interpersonal conflicts were more likely to be associated with ICM subjects, whereas political conflicts were more likely to be associated with non-ICM subjects.

This article examines resource problems and warfare in a sample of societies from eastern Africa. The frequency and predictability of resource problems are examined, as are two other dimensions of warfare: resource-taking and commission of atrocities. Differences between state and nonstate societies, as well as pacified and non-pacified societies, are also examined and shown to affect associations between resource and warfare variables.

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 paper proposes that the socio-cultural values of countries may be associated with increased mortality due to COVID-19. Using results from the World Values survey, the author assessed which values had the strongest association with a change in COVID-19 mortality in datasets consisting of all countries, upper-middle and high income economies, upper-middle income economies, high income economies, and advanced economies. The author also sought to determine whether the WVS values that were associated with COVID-19 mortality were also associated with general life expectancy. The results showed that COVID-19 mortality was increased in countries that placed a higher value on freedom of speech, political participation, religion, technocracy, post-materialism, social tolerance, law and order, and acceptance of authority. On the other hand, mortality was decreased in countries with high trust in major companies and institutions and that endorsed maintenance of order as a goal for a country. The author also found that values related to COVID-19 mortality did not predict general health outcomes, and that some values that predicted increased COVID-19 mortality actually predicted decreased mortality from other outcomes.

The present study tests the theory that intrasexual selection or male attraction may explain variation in male aggression in a sample of 78 societies. Measures of intrasexual selection include: male subsistence, male war mortality, polygyny, sex ratio, and wives variance. The authors claim support for the theory.

Can physiological variation in human populations be attributed to environmental variables? Arguing for the importance of phylogenetic comparative methods, the authors present the results of previous research by Holden & Mace (1997) on lactose intolerance as well as introduce new research on sex ratio at birth. The authors suggest that global variance in sex ratio at birth is an adapted response to the physiological costs of giving birth to boys in high fertility populations.

There is disagreement between existing theories on the relationship between leisure time and cultural complexity. This study tests Chick's (1986) hypothesis that simple and complex societies have more free time than those of moderate complexity. The relationship between cultural complexity and the economic productivity of children is also examined.