A METAANALYSIS OF ESP STUDIES CONTRASTING HYPNOSIS AND A COMPARISON CONDITION

This meta-analysis examined 25 ESP studies from 12 chief investigators . No potential moderator variable correlated significantly with ESP ef fect size (pi) under either hypnosis or the comparison condition. Ther e was cumulative ESP-test significance for hypnosis, but this signific ance may be inflated by nonindependence of study outcomes within chief investigator. For both experimental conditions, chief investigator wa s associated with significant heterogeneity of outcomes. In ESP analys es based on chief investigator, neither the contrast, nor either of th e experimental conditions, showed significance. The sum of scored flaw s per study did not correlate significantly with outcomes, but the mea n number of such flaws was substantial. For the same-subjects studies suitable for analysis, testing order interacted significantly with the experimental manipulation. The hypnosis-comparison contrast was signi ficant only when the comparison condition preceded hypnosis. This sign ificance was due, substantially, to psi-missing in the comparison cond ition. These and other findings make it difficult to draw substantive conclusions from the current database.