Does Psi Exist? Comments on Milton and Wiseman's (1999) Meta-Analysis of Ganzfeld Research

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Plain English Summary

In 1999, two researchers declared the ganzfeld telepathy experiment — where someone in sensory deprivation tries to receive mental images from a sender — was a bust. Storm and Ertel disagreed. They assembled 79 studies spanning nearly three decades and found people guessed the right image 31% of the time when chance predicts 25%. That gap sounds modest, but the odds of it being a fluke were less than one in a billion. This telepathy-like effect appeared in every subset of studies, including the very batch skeptics used to declare it dead. Their verdict: the ganzfeld reliably produces anomalous communication, and the negative conclusion came from too small a slice of the evidence.

Research Notes

Pivotal rebuttal in the ganzfeld telepathy debate, published in the same APA journal as Milton and Wiseman's challenge. Established the unified 79-study database and population parameters (ES = 0.14, hit rate 31%) that became standard reference points for the next two decades of ganzfeld meta-analyses. Speaks directly to Controversy #1.

Re-analysis and extension of Milton and Wiseman's (1999) negative ganzfeld meta-analysis, which had found ES = 0.013 (Z = 0.70, p = .24) across 30 studies and questioned whether the ganzfeld paradigm produces replicable ESP. By assembling four databases spanning 1970–1997 — Honorton's (1985) 28 studies, 11 overlooked 1982–1986 studies, Bem and Honorton's (1994) 10 autoganzfeld studies, and Milton and Wiseman's 30 studies — a unified 79-study database yielded ES = 0.138, Stouffer Z = 5.66, p = 7.78 × 10⁻⁹, with an overall hit rate of 31% vs. 25% MCE. Bidirectional psi effects were significant in every database. The authors conclude that the ganzfeld remains a replicable technique for demonstrating anomalous communication.