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 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.

This article offers a detailed analysis of neurophysiological processes involved in altered states of consciousness. Cross-cultural hypotheses concerning altered states of consciousness are tested.

This article explores ecological, religious, and social correlates of human sacrifice and cannibalism in a cross-cultural sample. Support is found for associations between human sacrifice and population density, population pressure, war for land and resources, and a low hierarchical focus of religion. Human sacrifice among Aztecs is given particular attention.

This article examines shamans and other types of magico-religious healers. Agriculture and political integration are suggested to influence the transformation of shamans into shaman/healers, healers, or possession-trance mediums.

The author builds upon previous research (Winkelman 1998) to further elucidate the cross-cultural predictors of institutionalized human sacrifice. The author considers a range of ecological factors and political variables, particularly geopolitical dynamics and intra- and inter-group relations. Other factors were explored, including social complexity and social structures. The author identifies the lack of an effective superordinate political authority as a main determinant in similar behaviors contemporarily (e.g. suicide bombers, beheadings, public brutality in civil war).

This article offers a detailed analysis of neuropsychopsiological processes involved in altered states of consciousness (ASC) in order to design and evaluate a psychophysiological model of trance states. Cross-cultural hypotheses concerning ASC are tested.

The authors examine the relationship between magico-religious practitioner type and socioeconomic variables in order to present a typology of magico-religious practitioners. Three bases for magico-religious practitioners are discussed in terms of selection procedures and activities. Several hypotheses are empirically tested, and descriptive generalizations derived from analyses are presented.

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.