Inductancias MEMS

INTRODUCTION

The pages that follow contain my admittedly personal reflections upon the current state of parapsychology. Lest the reader feels it to be somewhat indulgent of me to engage in such personal reflections upon what is essentially a scientific question, I should perhaps justify my approach.

My main area of research is anomalistic psychology (e.g., French, 1992, 2001, 2009). The main aim of anomalistic psychology is to try to account for the kind of bizarre experiences that people often report and label as paranormal, but with-out assuming that psi necessarily exists. In the spirit of John Palmer’s progressive skepticism (Palmer, 1986), it is an attempt to produce and empirically test non-paranormal accounts of ostensibly non-paranormal phenomena. One of the most strik-ing, if not surprisstrik-ing, conclusions from research in this area is that our personal beliefs are crucial in determining how we interpret information, from the levels of basic perception and memory up to the level of judgments about complex sets of data. I do not believe that it is possible for human beings to be unbiased when it comes to judging controversial issues such as the existence of psi and I thus make no claim to be a neutral assessor of the evidence. I think I owe it to the reader, therefore, to be completely up-front about my current position with respect to the psi debate.

I am what Palmer (1986) would call a conventional theorist (i.e., I have a pref-erence for non-paranormal rather than paranormal explanations of ostensibly paranormal events). However, I can honestly say that I lived much of my life

as a believer in the paranormal. As a teenager, I was enthralled by the feats of Uri Geller and delighted that scientists had allegedly validated his claims. Parachological topics were rarely mentioned during my days as an undergraduate psy-chology student, but I read around a little. In particular, I found Eysenck’s arguments in support of psi very persuasive (e.g., Eysenck, 1957). My conversion to skepticism can be explained by the reading of a single book, James E. Alcock’s (1981) Parapsychology: Science or Magic? Alcock, a social psychologist, opened my eyes to the fact that there were some quite plausible non-paranormal explan-ations for ostensibly paranormal events. He also made me realize that there were books and papers written by skeptics, a fact that I had not really fully appreciated until then. I took out a subscription to Skeptical Inquirer and my conversion from true believer to extreme skeptic was complete!

Since that time, my attitudes have mellowed somewhat and I now prefer to think of myself as a moderate skeptic (although I am pretty certain that many parapsychologists would not agree!). I am still a conventional theorist, but I am very much in favor of the continuation of mainstream parapsychological research.

Some areas of parapsychology have produced positive results that are a real chal-lenge to critics and such evidence merits (although it rarely receives) serious con-sideration by the wider scientific community. Moderate parapsychologists on the other side of the psi debate recognize the value of the conventional theorists’

approach. They willingly acknowledge that most paranormal claims are not true instances of paranormal forces in action. My only disagreement with such inves-tigators is at the level of “gut feelings”: Whereas they feel that paranormal forces probably do exist, I feel that they probably do not. But of course I could be wrong.

It should be noted that I have used the terms believer and skeptic throughout this essay even though there are good arguments for abandoning such value-laden terms in favour of such terms as advocate and counteradvocate (or, as already referred to, conventional theorist) when referring to proponents and critics of para-normal claims, respectively. My reasons for doing so are that the terms believer and skeptic, although imprecise, are in common usage to refer to these two points of view. My usage of the terms should obviously not be taken to imply that those who call themselves skeptics do not have beliefs or that those whom we com-monly refer to as believers never adopt a skeptical approach to evidence. I agree with Palmer (1986) when he calls for skepticism to be adopted by both sides in the psi debate, insofar as both advocates and counteradvocates should adopt an attitude of critical but open-minded doubt whenever they are considering any unproven claims in this domain.

THE CURRENT STATE OF PARAPSYCHOLOGY

If one were approaching the subject of parapsychology for the first time, it would seem reasonable to attempt an initial assessment of the state of the field by con-sulting book-length reviews. If one were simply to enter the nearest bookshop and choose a popular treatment of the paranormal, one would almost certainly end up reading an uncritical account of allegedly demonstrated paranormal

phenomena. But suppose that our hypothetical seeker after truth is a little bit more sophisticated than that and realizes that you cannot believe everything you read in books. She further appreciates that publishers may well give in to the temptation to sell more books by preferentially publishing those that pander to the public’s desire to believe in matters paranormal rather than to critically assess the available evidence.

Such a reader may therefore seek out books written by well-qualified academ-ics working in established university departments in preference to those written primarily for a popular readership. Unfortunately, such books do not speak with one voice with respect to the body of evidence pertaining to paranormal claims.

Dean Radin (1997), for example, clearly believes that the scientific evidence in support of the existence of paranormal forces is overwhelming and that it is only ignorance and prejudice on the part of the wider scientific community that prevents the universal acceptance of this fact (see also Radin, 2006). In his words:

The effects observed in a thousand psi experiments are not due to chance, selective reporting, variations in experimental quality, or design flaws.

They’ve been independently replicated by competent, conventionally trained scientists at well-known academic, industrial, and government-supported laboratories worldwide for more than a century. (Radin, 1997, p. 275)

On the other hand, the long-standing critic of parapsychology David Marks (2000) concluded, after reviewing seven areas of parapsychological research:

“My own beliefs are as they are—toward the extreme of disbelief—because the evidence as I see it warrants nothing more” (p. 308).

My own current position is somewhere between the two extremes represented by Radin and Marks. I find myself in fairly full agreement with the final paragraph of a third book-length review, this time by parapsychologists Harvey Irwin and Caroline Watt (2007):

In the final analysis what fairly can be said of parapsychology?. . . [As] far as spontaneous cases are concerned it seems likely that there are numerous instances of self-deception, delusion, and even fraud. Some of the empirical literature likewise might be attributable to shoddy experimental procedures and to fraudulent manipulation of data. Be that as it may, there is sound phenomenological evidence of parapsychological experiences and experi-mental evidence of anomalous events too, and to this extent behavioral scientists ethically are obliged to encourage the investigation of these phe-nomena rather than dismissing them out of hand. If all of the phephe-nomena do prove to be explicable within conventional principles of mainstream psychology surely that is something worth knowing[. . .]; and if just one of the phenomena should be found to demand a revision or an expansion of contemporary psychological principles, how enriched behavioral science would be. (pp. 260–261)

In addition to the controversy over the existence of psi, parapsychology has also long been the subject of criticism concerning its scientific status. Despite the fact that in 1969 the Parapsychology Association was admitted to the presti-gious American Association for the Advancement of Science, many critics have condemned parapsychology to the status of pseudoscience (e.g., Alcock, 1981;

Bunge, 1991; Radner & Radner, 1982). Different commentators sometimes give different reasons for their condemnation, but as Truzzi (1996) points out, there are real problems in trying to distinguish true science from pseudoscience. Edge, Morris, Palmer, and Rush (1986) argue that it is impossible to demarcate clearly between science and pseudoscience and that one should instead consider each discipline in terms of the degree to which it meets a number of benchmarks that characterize good science. While they acknowledge that parapsychology falls a little short on some of these benchmarks, they claim that it does not completely fail on any of them. I tend to agree (French, 2009). The best research in parapsy-chology appears to me to be at least as scientific as that in other areas of social science, including psychology. Of course, there are many examples of shoddy research in all disciplines but it is only fair to judge a discipline on the basis of its highest quality output. In other words, I do not think that experimental parapsychologists should change their basic approach too much. The best hope for the future of parapsychology lies in adhering as strictly as possible to the basic principles of science.

WHAT ARE THE PROBLEMS THAT PARAPSYCHOLOGY NEEDS TO SOLVE TO IMPROVE THE STATE OF THE FIELD?

I am not so presumptuous as to claim that the issues I am about to discuss represent a definitive list of the most important issues for parapsychology to address. I have simply taken the opportunity to reflect on the sort of evidence that might cause a moderate skeptic such as myself to cross that threshold from thinking that psi probably does not exist to thinking that it probably does.

I would agree with the late Robert Morris (2000) that further thought needs to be given to the strengths and limitations of meta-analysis. Parapsychologists such as Radin (1997) appear to have embraced meta-analysis as providing the royal road to scientific respectability. However, it is undoubtedly true that, although meta-analysis provides an extremely powerful tool when used appropri-ately, it is also open to abuse (see, e.g., Eysenck, 1994). This has been highlighted recently by the debate following the publication of Milton and Wiseman’s (1999) meta-analysis of 30 ganzfeld studies carried out by seven different investi-gators. Although Bem and Honorton’s (1994) original meta-analysis of 11 ganz-feld studies appeared to provide strong evidence of a replicable anomalous cognition effect, Milton and Wiseman’s analysis did not (although it should be noted that some commentators have argued that this is because many of the more recent studies were process-oriented rather than proof-oriented; Bem, Palmer, & Broughton, 2001; Storm, 2000; Storm & Ertel, 2001).

Milton (1999) discussed many potential problems with the use of meta-analysis in parapsychology. Furthermore, the debate in response to this paper (Schmeidler & Edge, 1999) reveals a wide range of opinions regarding the appro-priate use of such techniques. Parapsychologists are not only carrying out an essential service for their own discipline by attempting to resolve these issues but are also helping other disciplines that employ meta-analysis. They should be applauded for this. The conclusion cannot be avoided, however, that at this stage it would appear to be premature for parapsychology to put all its eggs into the meta-analytic basket (see also Utts, 1991, and associated commentaries).

Problems in interpreting meta-analyses of parapsychological studies were again highlighted when Bo¨sch, Steinkamp, and Boller (2006) published a meta-analysis of 380 experimental investigations of psychokinesis (PK) employing random event generators (REGs). They concluded that there was a very small but signifi-cant overall effect size, which “even if incredibly small, is of great fundamental importance” (p. 517). However, they also noted that “study effect sizes were strongly and inversely related to sample size and were extremely heterogeneous”

(p. 497). They argued that the most parsimonious explanation for the results was in fact in terms of publication bias. In other words, the apparently significant result of the meta-analysis was an artefact not a reflection of a genuine psi effect.

Wilson and Shadish (2006), in commenting upon their analysis, did not accept that any significant effect, no matter how small, is fundamentally important.

They suggested that PK researchers should focus on producing larger effects or on specifying the conditions under which they would be prepared to accept the null hypothesis. Radin et al. (2006), in their comment, argued against the publi-cation bias explanation but did not convince Bo¨sch et al. that such bias is an implausible explanation of the pattern of results found in the meta-analysis. How-ever, the latter do acknowledge that their explanation cannot be proven prior to the introduction of compulsory registration of trials.

The fact that Milton and Wiseman’s meta-analysis failed to replicate the results of Bem and Honorton’s meta-analysis highlights a criticism that still con-tinues to plague parapsychology—lack of replicability. It can be reasonably argued (e.g., Utts, 1991) that old-fashioned ideas of replication, based as they are upon misunderstandings of the concepts of statistical power and statistical significance, are in many ways inferior to the consideration of patterns of effect size across different experiments and experimenters. The latter is, of course, exactly the type of information that meta-analysis can provide. But given the legitimate doubts that exist regarding the use of meta-analysis, the fact that meta-analyses can fail to replicate each other, and the fact that the results of meta-analyses can be open to different interpretations, it appears that the repli-cability issue has not yet been resolved for parapsychology.

Several commentators (e.g., Edge et al., 1986) have quite rightly pointed out that, contrary to popular opinion, direct replications are quite rare in all areas of science, including psychology. Furthermore, many psychological effects reported in the literature have turned out to be difficult, sometimes impossible, to replicate. This often comes as a complete revelation to new postgraduate

students who, having been raised upon a diet of practical classes based upon carefully chosen, very robust effects, are shocked to discover that often they can-not even replicate the basic effects that they intended to investigate in their own research. It is argued that it is therefore unfair to single out parapsychology as a discipline that has a particular problem in this respect. Is this another example of stricter standards being applied to parapsychology than to psychology? Indeed it is—but with good reason. In some important respects, the publication of an unreplicable effect in psychology simply matters less than it matters in parapsy-chology. I can perhaps illustrate this by citing an example from my own research in cognition and emotion.

In 1991 Anne Richards and I (Richards & French, 1991) published results in partial support of a novel prediction from Williams, Watts, MacLeod, and Mathews (1988) regarding the effect of anxiety on implicit memory. Unfortu-nately, despite our best efforts we were completely unable to replicate the basic effect using other measures of implicit memory. We submitted these negative findings to a number of journals but could not get the paper accepted. The moti-vation to write-up and submit negative findings in psychology is never very strong, as it is more or less certain that the “best” journals would not publish them. It is doubtful that we will ever find the time to re-submit them again. Pub-lication bias for positive results is, in my opinion, a much bigger problem within psychology than parapsychology. Needless to say, we let colleagues know infor-mally that we were unable to replicate the effect and that we now believe the original reported effect to be unreliable, but inevitably our initial paper is still cited as offering support for the prediction by Williams et al. (1988).

Why are such unreplicable effects less important in psychology than parapsy-chology? Firstly, because in the fullness of time a few papers with negative results will be published—and many other experimenters will also have failed to repli-cate the effects but not bothered to write-up their results. Thus, word will spread along the informal networks of researchers in this area. It may take some time, but eventually it will be generally accepted that this particular interesting hypothesis is not valid. But secondly—and much more importantly—whether or not the hypothesis is valid, no radical revision of our existing scientific world view would be required. In the case of tests of the psi hypothesis, positive results would require exactly such a radical revision. It is therefore much more important that we establish whether or not the claimed effects are replicable. As Pierre-Simon Laplace once said, “The weight of the proofs must be suited to the oddness of the facts.”

Furthermore, although there are many claimed effects within the psychological literature that are unreplicable, there are many which are extremely robust (e.g., visual illusions, the Stroop effect, etc.). Parapsychologists do not, unfortunately, appear to be able to demonstrate any equally robust parapsychological effect. I guess we are back at the old-fashioned notion of replicability as referring to an effect which would be reasonably likely to be demonstrated by anyone who took the time and trouble to follow the appropriate procedures. Although it may not be a very sophisticated view of replicability, there is no doubt that if parapsychologists could

find the magic formula to produce such effects it would a have a huge impact on the credibility and wider acceptance of their discipline.

It is sometimes argued by critics (e.g., Glymour, 1987; Wilson & Shadish, 2006) that the effect sizes typically found in parapsychology are so tiny that no sensible person would choose to consider them paranormal as opposed to being due to some (possibly unknown) combination of ordinary factors. This has never been an argument with which I have felt particularly comfortable. If an effect is replicable and (preferably) statistically significant, it deserves an explanation.

It is notable that the effect sizes typically reported in apparently well-controlled parapsychological studies are orders of magnitude less than the effects typically claimed by self-professed psychics. The crucial importance of reliably producing a convincing demonstration of even a tiny psi effect under well-controlled con-ditions is that to many scientists, myself included, this would require the kind of radical revision of worldview that would make at least some of the larger scale paranormal claims seem more plausible. Even though I believe that small effect sizes should be taken seriously, it goes without saying that, if parapsychologists can find some way to amplify these weak effects, this would again add to the cred-ibility of the discipline.

Furthermore, if a way could be found to increase effect sizes this would open up the possibility of practical applications for psi. Radin (1997), amongst others, has discussed possible practical applications of psi, including applications in medicine, military and intelligence work, crime detection, business, and technology. There is little doubt that considerable amounts of money have been invested by govern-ments, technological industries, the military, and intelligence agencies in trying

Furthermore, if a way could be found to increase effect sizes this would open up the possibility of practical applications for psi. Radin (1997), amongst others, has discussed possible practical applications of psi, including applications in medicine, military and intelligence work, crime detection, business, and technology. There is little doubt that considerable amounts of money have been invested by govern-ments, technological industries, the military, and intelligence agencies in trying