This study tests the relationship between population pressure and social evolution in agricultural societies. The author predicts that population pressure will be positively related to the evolution of descent, political integration, and class stratification. Results support this prediction.

Expanding on the author’s previous findings, this article examines the social and economic variables that may explain the cultural evolution of religious practitioners. With a 47 society sample, the author found that subsistence activities and socio-political conditions predict magico-religious practitioner types (sorcerers/witches, priests, shamanistic healers, mediums, healers, shaman/healers, and shamans) with the strongest results being from subsistence and political organization. He then used these findings to theorize about the biogenetic bases of religion in societies.

This article seeks to reevaluate the widespread assumption that hunter-gatherers lack the longevity that people in the modern, industrialized world enjoy. Through modeling life expectancy, mortality, and other demographic trends among extant hunter-gatherer, gatherer-horticulturalists, and horticulturalists societies they are able to challenge this belief. The authors conclude that longevity is a "novel feature of Homo sapiens" and that seven decades seems to be the natural lifespan of a human.

Researchers examined both why so many language are spoken today, and why they are so unevenly distributed geographically. Instead of looking at correlative tests, this study uses a process-based simulation model that attempted to predict both the number or precolonial languages in Australia as well as the number of languages per unit of land. The model was based upon three basic assumptions: 1) humans fill unoccupied spaces; 2) rainfall limits population density; 3) groups divide after reaching a maximum population. While researchers used the model strictly on the Australia continent, it was able to correctly explain 56% of spatial variation in language richness, and predict the total number of languages across the continent. The accuracy of this model concludes that climatic conditions and changes in group size are important factors in shaping language diversity patterns and therefore global human cultural diversity.

This study tests the relationship between mobility and technology among foragers, with the intent of applying findings to the archaeological record. In data analysis, mobility frequency is differentiated from mobility magnitude, and technological diversity is differentiated from technological complexity. Results suggest that mobility frequency is negatively associated with technological diversity while mobility magnitude is negatively associated with technological complexity.

Using both archaeological data from the Mesa Verde region and a Human Relations Area Files random sample of 25 worldwide societies, and another 10 from the American Southwest, the author looked to examine the relationship between changes in community size and settlements, agriculture intensification, and rules governing resource access. In particular the researcher wanted to examine the size of the group that controls the primary access to the main resource. After studying this global sample, the author takes an ethnographic look specifically at the Northern Anasazi in southewestern Colorado.

The author sampled 28 nonhierarchical, sedentary (at least partially), and demographically documented societies to examine the presence, size, and use of socially integrative facilities. Examing the ethnographic record from the Human Relations Area Files, the author looked to test the assumption that kivas were intended for communal ritual activity.

The dissertation in its entirety is an archaeological investigation of population aggregation among the Mesa Verde region Anasazi A.D. 900-1300. Chapters four and five of Adlers larger work focus on cross-cultural perspectives to inform discussion around resource access and community strength. Multiple different hypotheses were tested with different data sets, but the HRAF database and Standard Cross Cultural Sample were used throughout.

Researchers looked at four different demographic scenarios (altered mean vital rates (i.e., fertility and mortality), vital rate stochasticity, vital rate covariance, and periodic catastrophes) and their possible effects on the rapid population growth of contemporary human foragers and steady population decline of chimpanzees. They evaluated these variables and the various conditions that would favor a more sustainable zero population growth (ZPG) among 10 small-scale subsistence human populations (Agta, Ache, Hadza, Hiwi, Ju/’hoansi, Gainj, Tsimane, Yanomamo, Northern Territory Aborigines, and Herero) and five wild chimpanzee groups (Gombe, Kanyawara, Mahale, Ngogo, and Taï). The results state that the most effective modifications towards ZPG would include a combination of more than one of the four demographic scenarios tested, with the most realistic solution including both vital rate alteration and an increase in catastrophes.

While it is widely accepted that there are a multitude of variables that contribute to a society’s level of democracy, the authors of this study argue that the prevalence of consanguinity is one that is often overlooked. Using a sample of 70 nations, they tested the relationship between consanguinity (defined as marriage and subsequent mating between second cousins or closer relatives) and level of democracy (defined by both the Polity IV scale and the EIU Index) and found a significant negative relationship. Similarly, when controlled for a host of different variables in multiple regression analysis, the significant relationship between consanguinity and level of democracy held true.