This study tests the hypothesis that long-term experience of Apostolic Pentecostal glossolalia or "speaking in tongues" reduces the reactivity of biological stress response to normal or "daily" stressors. Glossolalia is a form of religious dissociation. Dissociation is a universal capacity often conflated with "trance." It refers to the partitioning of awareness associated with a variety of cross-cultural forms, from daydreaming and denial to possession trance, shamanic spirit journeys, and dissociative identity disorder. Dissociation is believed to reduce or filter stress by mediating evaluation of potential stressors and reactivity of the mechanisms of biological stress response. Previous studies have examined these mechanisms in clinical settings and in relation to secularized dissociative phenomena, but few have attempted to evaluate the stress reducing and filtering capacities of culturally relative dissociation in situ. This is important, as forms of dissociation, such as meditation and hypnosis, are used in medical application for improving health by reducing stress. The current study sought to isolate a form of culturally relative dissociation in assessing its influence on biological stress response. This was accomplished through a two year investigation among Apostolics in New York's mid-Hudson Valley.

Pentecostalism is a form of evangelical Protestantism that rose to prominence over the 20^th century to become a global phenomenon. Apostolics are a traditional denomination defined by belief in glossolalia as absolutely necessary to convey acceptance of Christ. Sixty participants were sampled with regard to glossolalia, biological stress, and other relevant factors. Biological stress was measured by collecting saliva samples to measure diurnal cycles of cortisol and α-Amylase production.

The data suggest that glossolalia is suggestively associated with a reduction in stress in response to normal stressors and significantly associated with positive mood and calmness. This supports a growing body of work validating the health-improving affects of religiosity and the claims of Pentecostals themselves. The broad implication of this research is that dissociation plays a role in stress-related health outcomes in religious dissociative contexts.