| Pe (ai pcan en Ti ar ite i Rt em Em oct aa — at Approved For Release 2000/08/08 : CIA-RDP96-00789R003200110001-4 Psychological Bulletin 1994, Vol. 115, No. 1, 4~18 Copyright 1994 by the American Psychological Association, Inc. 0033-2909/94/$3.00 Does Psi Exist? Replicable Evidence for an Anomalous Process of Information Transfer Daryl J. Bem and Charles Honorton Most academic psychologists do not yet accept the existence of psi, anomalous processes of informa- tion or energy transfer (such as telepathy or other forms of extrasensory perception) that are cur- rently unexplained in terms of known physical or biological mechanisms. We believe that the repli- cation rates and effect sizes achieved by one particular experimental method, the ganzfeld procedure, are now sufficient to warrant bringing this body of data to the attention of the wider psychological community. Competing meta-analyses of the ganzfeld database are reviewed, | by R. Hyman (1985), a skeptical critic of psi research, and the other by contributor to the ganzfeld database. Next the resu' C. Honorton (1985), a parapsychologist and major Its of 11 new ganzfeld studies that comply with guidelines jointly authored by R. Hyman and C. Honorton (1986) are summarized. Finally, issues of replication and theoretical explanation are discussed. The term psi denotes anomalous processes of information or energy transfer, processes such as telepathy or other forms of extrasensory perception that are currently unexplained in terms of known physical or biological mechanisms. The term is purely descriptive: It neither implies that such anomalous phe- nomena are paranormal nor connotes anything about their un- derlying mechanisms. Does psi exist? Most academic psychologists don’t think so. A survey of more than 1,100 college professors in the United States found that 55% of natural scientists, 66% of social scien- tists (excluding psychologists), and 77% of academics in the arts, humanities, and education believed that ESP is either an estab- lished fact or a likely possibility. The comparable figure for psy- a Daryl J. Bem, Department of Psychology, Cornell University; Charles Honorton, Department of Psychology, University of Edinburgh, Edin- burgh, Scotland. Sadly, Charles Honorton died of a heart attack on November 4, 1992, 9 days before this article was accepted for publication. He was 46. Para- psychology has lost one of its most valued contributors. I have lost a valued friend. This collaboration had its origins in a 1983 visit] made to Honorton’s Psychophysical Research Laboratories (PRL) in Princeton, New Jersey, as one of several outside consultants brought in to examine the design and implementation of the experimental protocols. Preparation of this article was supported, in part, by grants to Charles Honorton from the American Society for Psychical Research and the Parapsychology Foundation, both of New York City. The work at PRL summarized in the second half of this article was supported by the James S$. McDonnell Foundation of St. Louis, Missouri, and by the John E. Fetzer Foundation of Kalamazoo, Michigan. Helpful comments on drafts of this article were received from Debo- rah Delanoy, Edwin May, Donald McCarthy, Robert Morris, John Palmer, Robert Rosenthal, Lee Ross, Jessica Utts, Philip Zimbardo, and two anonymous reviewers. Correspondence concerning this article should be addressed to Daryl! J. Bem, Department of Psychology, Uris Hall, Cornell University, Ith- aca, New York 14853. Electronic mail may be sent to d.bem@cor- nell.edu. Approved For Release 2000/08/08 4 chologists was only 34%. Moreover, an equal number of psy- chologists declared ESP to be an impossibility, a view expressed by only 2% of all other respondents (Wagner & Monnet, 1979). We psychologists are probably more skeptical about psi for several reasons. First, we believe that extraordinary claims re- quire extraordinary proof. And although our colleagues from other disciplines would probably agree with this dictum, we are more likely to be familiar with the methodological and statisti- cal requirements for sustaining such claims, as well as with pre- vious claims that failed cither to meet those requirements or to survive the test of successful replication. Even for ordinary claims, our conventional statistical criteria are conservative. The sacred p = .05 threshold is a constant reminder that it is far more sinful to assert that an effect exists when it does not (the Type I error) than to assert that an effect does not exist when it does (the Type II error). Second, most of us distinguish sharply between phenomena whose explanations are merely obscure or controversial (e.g., hypnosis) and phenomena such as psi that appear to fall outside our current explanatory framework altogether. (Some would characterize this as the difference between the unexplained and the inexplicable.) In contrast, many laypersons treat all exotic psychological phenomena as epistemologically equivalent; many even consider deji vu to be a psychic phenomenon. The blurring of this critical distinction is aided and abetted by the mass media, “new age” books and mind-power courses, and “psychic” entertainers who present both genuine hypnosis and fake “mind reading” in the course of a single performance. Ac- cordingly, most laypersons would not have to revise their con- ceptual model of reality as radically as we would in order to assimilate the existence of psi. For us, psi is simply more ex- traordinary. Finally, research in cognitive and social psychology has sensi- tized us to the errors ara! biases that plague intuitive attempts to draw valid inferences from the data of everyday experience (Gilovich. 1991, Susbett & Ross, 1980; Tversky & Kahneman 1971). This leads us tu give virtually no probative weight to an- ecdotal or yournalstic seports of psi, the main source cited by : CIA-RDP96-00789R003200110001-4