Using data on 25 ethnolinguistic groups in the Austronesian language family, this study asks: does cooperation in games vary with socio-ecological differences across cultural groups? The authors suggest that cultural groups that cooperate in subsistence, tend to have intergroup conflict and less intragroup conflict, and are less socially stratified are more likely to play cooperative games compared to other groups. While the results support the first three hypotheses, there is insufficient data to support the fourth. The authors conclude that games serve as training ground for group norms and values.

Using data on 25 ethnolinguistic groups in the Austronesian language family, this study asks: does cooperation in games vary with socio-ecological differences across cultural groups? The authors suggest that cultural groups that cooperate in subsistence, tend to have intergroup conflict and less intragroup conflict, and are less socially stratified are more likely to play cooperative games compared to other groups. While the results support the first three hypotheses, there is insufficient data to support the fourth. The authors conclude that games serve as training ground for group norms and values.

Using data on 25 ethnolinguistic groups in the Austronesian language family, this study asks: does cooperation in games vary with socio-ecological differences across cultural groups? The authors suggest that cultural groups that cooperate in subsistence, tend to have intergroup conflict and less intragroup conflict, and are less socially stratified are more likely to play cooperative games compared to other groups. While the results support the first three hypotheses, there is insufficient data to support the fourth. The authors conclude that games serve as training ground for group norms and values.

In an attempt to explain communal conflict, this study investigated how customary institutions (i.e. legislatures, courts, and chiefs) may impact the communal conflict activity of groups in Africa. The authors suggest that customary authorities act as local enforcements to mitigate within-group conflict, therefore a higher number of customary institutions should decrease communal conflict. Using data from 143 politically relevant ethnic groups, the authors showed support for their hypothesis and demonstrated marginal support that more inclusive customary institutions would be associated with less communal conflict.

In an attempt to explain communal conflict, this study investigated how customary institutions (i.e. legislatures, courts, and chiefs) may impact the communal conflict activity of groups in Africa. The authors suggest that customary authorities act as local enforcements to mitigate within-group conflict, therefore a higher number of customary institutions should decrease communal conflict. Using data from 143 politically relevant ethnic groups, the authors showed support for their hypothesis and demonstrated marginal support that more inclusive customary institutions would be associated with less communal conflict.

The authors explore coalitional play fighting (in which teams of at least two play against each other to achieve a goal) across hunter-gatherer societies, with the theory that play of this type may be a mechanism for assessing strength and utility for future defense or warfare. When played against other communities, they propose coalitional play fighting can also serve to gauge strength of potential allies or formidability of potential enemies. In order to test their theories, they predict that, despite the large energy cost and risk of sports associated with coalitional play fighting, these types of games will be widespread in hunter-gatherer societies. In addition, they predict that of those exhibiting coalitional play fighting, many will play against other communities. In support of their hypotheses, they find that 54% of hunter-gatherer societies examined exhibit coalitional play fighting, of which 81% play against other communities.

The authors explore coalitional play fighting (in which teams of at least two play against each other to achieve a goal) across hunter-gatherer societies, with the theory that play of this type may be a mechanism for assessing strength and utility for future defense or warfare. When played against other communities, they propose coalitional play fighting can also serve to gauge strength of potential allies or formidability of potential enemies. In order to test their theories, they predict that, despite the large energy cost and risk of sports associated with coalitional play fighting, these types of games will be widespread in hunter-gatherer societies. In addition, they predict that of those exhibiting coalitional play fighting, many will play against other communities. In support of their hypotheses, they find that 54% of hunter-gatherer societies examined exhibit coalitional play fighting, of which 81% play against other communities.

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).

Researchers investigated the variation of land tenure systems across forager societies using the economic defensibility model. The study attempted to explain the variation in tenure systems across 30 hunter-gatherer societies. Using data on defense and sharing of resources among groups, and indicators of resource density, resource predictability, and competition for resources, the researchers were unable to explain the variation. This study highlights the vast range of diversity and complexity of foragers subsistence strategies, and proposes that it may be more telling to conceptualize tenure systems among hunter-gatherer societies as assemblages of multiple property regimes. While there was no overall evidence that environmental variables of resource density and predictability explain variation in tenure systems, researchers did find that increasing population density, and greater competition for resources leads to greater territoriality.

In this study, the authors inspect the relationship between religion, morality, and cooperation by examining the extent to which people associate their deities with moral concern. Using data from 2,228 individuals in 15 different field sites, they find that on average, people tend to ascribe at least some moral concern to their deities, and this effect is stable even after controlling for the influence of explicitly moralistic deities that these societies also worship. The authors also find that ratings of moral concern are not necessarily very high, even for deities that are typically considered to be moralistic, and that there is individual-level variation in the degree of moral concern attributed to deities. In addition, there is an individual-level correlation between how morally interested two selected deities are conceived to be and that being male or more educated decreases the likelihood of associating deities with moral concern. These findings challenge the longstanding belief that belief in moralistic deities is unique to certain societies or religions and instead suggest that the association between deities and moral concern is more widespread and variable, and suggest that the moral character of gods may be tied to cooperation within societies.