This paper examines the relationship of productive variation in land between ethnic groups to determine if an increased range of producible goods will increase trade, thus decreasing language diversity between neighboring groups. The author initially found that high-variation in land production lessened the diversity of language between ethnic groups in that area. To further test this correlation, the author found that high-productive variation increased trade and exogamous marriage and decreased inter-ethnic conflict. Based on these findings, the author suggests that neighboring ethnic languages co-evolved through the economic benefit of inter-ethnic trade and social interaction.

This paper examines the relationship of productive variation in land between ethnic groups to determine if an increased range of producible goods will increase trade, thus decreasing language diversity between neighboring groups. The author initially found that high-variation in land production lessened the diversity of language between ethnic groups in that area. To further test this correlation, the author found that high-productive variation increased trade and exogamous marriage and decreased inter-ethnic conflict. Based on these findings, the author suggests that neighboring ethnic languages co-evolved through the economic benefit of inter-ethnic trade and social interaction.

This paper examines the relationship of productive variation in land between ethnic groups to determine if an increased range of producible goods will increase trade, thus decreasing language diversity between neighboring groups. The author initially found that high-variation in land production lessened the diversity of language between ethnic groups in that area. To further test this correlation, the author found that high-productive variation increased trade and exogamous marriage and decreased inter-ethnic conflict. Based on these findings, the author suggests that neighboring ethnic languages co-evolved through the economic benefit of inter-ethnic trade and social interaction.

This paper examines the relationship of productive variation in land between ethnic groups to determine if an increased range of producible goods will increase trade, thus decreasing language diversity between neighboring groups. The author initially found that high-variation in land production lessened the diversity of language between ethnic groups in that area. To further test this correlation, the author found that high-productive variation increased trade and exogamous marriage and decreased inter-ethnic conflict. Based on these findings, the author suggests that neighboring ethnic languages co-evolved through the economic benefit of inter-ethnic trade and social interaction.

This paper examines the relationship of productive variation in land between ethnic groups to determine if an increased range of producible goods will increase trade, thus decreasing language diversity between neighboring groups. The author initially found that high-variation in land production lessened the diversity of language between ethnic groups in that area. To further test this correlation, the author found that high-productive variation increased trade and exogamous marriage and decreased inter-ethnic conflict. Based on these findings, the author suggests that neighboring ethnic languages co-evolved through the economic benefit of inter-ethnic trade and social interaction.

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.

Previous research into the origins of human violence and warfare has oftentimes been inconclusive and controversial. This paper examines two alternative theories as to the evolution of human violence using archaeological records on sharp force trauma (SFT) and blunt force trauma (BFT). The study is limited to 13 different California ethnolinguistic groups. Researchers find that violence is not predicted by sociopolitical complexity, but rather by environmental productivity. This supports the idea that in contexts of resource scarcity, the perceived benefits to engage in lethal aggression may outweigh perceived costs.

In this study, the authors draw from intensity theory and combine previous research from the fields of behavioral ecology, economics, and social evolution to analyze drivers in the emergence and persistence of inequality across the world. They propose that environmental heterogeneity and circumscription (the difficulty of moving and establishing oneself in a new environment relative to remaining in the current one) play a significant role in the stratification of societies. Their results indicate that situations arise from various environmental conditions and levels of circumscription that may result in an individual giving up autonomy for material gain, thus favoring inequality.

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.

The authors evaluated an alternative theory to the traditional productivity theory. They posit that food surplus did not precede the emergence of hierarchy, rather, the productivity advantage of cereal cultivation over tubers and roots as the catalyst for state societies. Their theory found support with a sample of societies from the present-day, Classical Antiquity, Neolithic period and pre/post Columbian Exchange. The results suggest social complexity emerged with cereal cultivation, rather than agriculture alone.