Comments on Rao's Article on “The Scientific Credibility of ESP”

Rao (p. 416) implies that we did not read Barry's (1968) article in the original and as a result unfairly state that Barry's report is incomplete. The focal point of investigations such as Barry's should be a specification of the techniques for control of extraneous variables, and this is completely lacking for both versions of the Barry report.

Rao (p. 418) refers to our survey of belief in E.S.P. as flawed in certain respects such as lacking a statistical analysis and failing to match groups on age. It should hardly be necessary to point out that a survey is designed to measure values on a state variable and is not meant to isolate causes; our report of this survey was meant only to serve as a reference point and was only incidentally related to the purpose of our article. Rao also questions the generality of our findings which indicated a high degree of disbelief in E.S.P. among the psychology staff at C.S.U.N. While no generality is claimed on the basis of this single study, it can be stated that historically the skepticism of academic psychologists has been so pronounced that one prominent parapsychologist wrote an article which centered on psychologists’ lack of interest in E.S.P. (McConnell, 1969) and another found it expedient to disqualify psychologists as critics of E.S.P. (Rhine, 1972). An extensive survey conducted by Monnet and Wagner (1978) is also in accord with our results.

Rao (p. 426) comments that the failure of E.S.P. to function at the gaming tables does not necessarily question its existence since the size of the effect could be inadequate to overcome the house “take.” The house take at dice and blackjack can be held to less than one percent with intelligent play; thus if the E.S.P. effect is too small to be useful at such games, we can at least conclude that its size lies somewhere between 0 and 1 percent (inclusive).

Rao (p. 425) attempts to justify the elasticity of the E.S.P. hypothesis on the grounds that supporters of phenomena such as hypnosis and subliminal perception have indulged in similar speculations about causes. We do not believe that this similarity strengthens the case for E.S.P., but rather that it weakens the case for hypnosis and subliminal perception. We do agree with Rao, however, in this sense: phenomena which present no better evidence than E.S.P. should be accorded no greater credibility.