Pahnke’s ‘Good Friday Experiment’: a long-term follow-up and methodological critique
Doblin, R.
This methodological critique and long-term, between-subjects, follow-up study (n=16) challenges how the mystical experiences occasioned by psilocybin were measured during Walter Pahnke's infamous 'Good Friday experiment' (1963) on the basis of its imprecise questionnaire assessment and unsuccessful placebo blinding. However, all psilocybin subjects participating in the long-term follow-up, but none of the controls, still considered their original experience to have had genuinely mystical elements and to have made a uniquely valuable contribution to their spiritual lives even 27 years after.
Abstract
Introduction: To investigate the potential of psychedelic drugs to facilitate mystical experience, W. Pahnke (1963) administered psilocybin or placebo to 20 White male Protestant divinity students before Good Friday services. The present study critiques the preparation phase of the experiment, Pahnke's questionnaire for measuring mystical experience, and completeness of his reporting.Methods: Between 1986 and 1989, the present author recorded personal interviews with 16 of the original Ss. All 16 were re-administered the 100-item questionnaire used for 6-mo follow-up in the original experiment. The original experiment found that psilocybin Ss who experienced a mystical experience would, after 6 mo, report a substantial amount of positive, and virtually no negative, persisting changes in attitude and behavior.Results: The present study further supports these findings.