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 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.

This article investigates a cultural patterning of altered states of consciousness. The authors use an ordinal variable for a society's trance type; its four levels are 1) trance, 2) trance and possession trance, 3) possession trance, and 4) neither type. Results suggest that trance type is associated with measures of societal complexity and subsistence economy. Regional differences and the effects of diffusion are also examined.

This article tests hypotheses relating altered states of consciousness, healing and social structure variables such as gender stratification, female participation, and kinship structure. Results did not support an association between ASCs and gender stratification, but did suggest distinct correlates of possession versus trance healing.

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 book investigates possession and possession-trance. While the author focuses on a case study of Haiti, there are also a handful of cross cultural tests performed. Results suggest that societal complexity is associated with belief in possession-trance, rather than possession alone.

Anthropologists have claimed that possession trance– an altered state of consciousness from spirit possession– is a psychosocial phenomenon. In particular, they argue that it is related to levels of social complexity, rigidity, and separation in gender participation. The author tests this claim through Bayesian hierarchical generalized linear models and phylogenetic comparative methods, but finds that possession trance is only correlated with social complexity and rigidity, not separation in gender participation.

This study examines correlates of possession trance among cultures in sub-Saharan Africa. Several variables were tested (including community organization, marriage form, family form, and settlement pattern) but only a few were related to possession trance. Results indicate that the presence of slavery, stratification, and role and structure differentiation are significantly associated with possession trance.

This dissertation discusses the divided theoretical approach to how reincarnation, animism, spirits, and general religious beliefs occur within societies cross-culturally. Matlock offers evidence to support Tyler, contradicting the generally accepted Durkheimian approach, arguing that the belief about souls and spirits may originate in dreams and other empirical experiences, in turn informing and shaping social organization. Durkheim argued the opposite, claiming that religious beliefs reflect social organization such as the clan and kinship. The author states 33 quantitative hypotheses to be tested using 30 of the first 60 sample societies available in the HRAF Probability Sample.