Factor Analysis of the Mystical Experience Questionnaire: A Study of Experiences Occasioned by the Hallucinogen Psilocybin
Katherine A. Maclean, Jeannie‐marie Leoutsakos, Matthew W. Johnson, Roland R. Griffiths
Journal for the Scientific Study of Religion December 1, 2012 DOI: 10.1111/j.1468-5906.2012.01685.x
Summary
Remarkably, the mystical experiences occasioned by psilocybin, a powerful hallucinogen, can be precisely measured. A psychology investigation involving 1,602 participants who ingested psilocybin utilized exploratory factor analysis to validate a 30-item Mystical Experience Questionnaire. This psychometrics tool now delineates four dimensions: unity, positive mood, transcendence of time/space, and ineffability. A second sample of 440 confirmed this structure. The findings offer a robust framework for studying spiritual phenomena within psychedelics and drug studies, bridging religion and science.
Abstract
A large body of historical evidence describes the use of hallucinogenic compounds, such as psilocybin mushrooms, for religious purposes. But few scientific studies have attempted to measure or characterize hallucinogen‐occasioned spiritual experiences. The present study examined the factor structure of the Mystical Experience Questionnaire (MEQ), a self‐report measure that has been used to assess the effects of hallucinogens in laboratory studies. Participants (N = 1,602) completed the 43‐item MEQ in reference to a mystical or profound experience they had had after ingesting psilocybin. Exploratory factor analysis of the MEQ retained 30 items and revealed a four‐factor structure covering the dimensions of classic mystical experience: unity, noetic quality, sacredness (F1); positive mood (F2); transcendence of time/space (F3); and ineffability (F4). MEQ factor scores showed good internal reliability and correlated with the Hood Mysticism Scale, indicating convergent validity. Participants who endorsed having had a mystical experience on psilocybin, compared to those who did not, had significantly higher factor scores, indicating construct validity. The four‐factor structure was confirmed in a second sample (N = 440) and demonstrated superior fit compared to alternative models. The results provide initial evidence of the validity, reliability, and factor structure of a 30‐item scale for measuring single, hallucinogen‐occasioned mystical experiences, which may be a useful tool in the scientific study of mysticism.