Ray Hyman
It is often implied that the research findings within our field constitute a death blow to materialism. I am puzzled by this claim, since I thought that few people were really so unsophisticated as to mistake our concepts for reality.
Martin Johnson (1976) All the chapters in this book provide much food for thought. Both the critics and the defenders of parapsychological claims raise issues that, given time and rela-tively unlimited space, I am tempted to discuss. Given that neither my time nor my space is unlimited, I will restrict my comments to some of the provocative opinions contained in Chris Carter’s chapter, “Persistent Denial: A Century of Denying the Evidence.”
Carter assails the “materialism” of science. His characterization of this materi-alism is rather simplistic. It is true that scientists work within a materialistic framework. They could not do otherwise and still do science. Science came into being as a way to explain the world in terms of material rather than spiritual or supernatural substances. Materialism provides a working framework for doing sci-ence. Spiritual and supernatural explanations of phenomena have been with us since our species began raising questions about our origins and the meaning of life. Such explanations, which attribute happenings to idiosyncratic gods and supernatural forces, do not foster the search for lawful, predictable, and control-lable causes. It was the advent of modern science, fuelled by the willingness to
search for non-supernatural causes, that enabled, and continues to enable, the explosion of knowledge and technology.
Carter seems to believe that materialism is some sort of rigid straitjacket that prevents scientists from accepting the reality of his brand of supernaturalism.
A materialistic framework is necessary to do scientific work. However, people can work as scientists and still privately adhere to a variety of other belief systems. Most of the earlier scientists were devoutly religious. Many prominent scientists today openly profess a deep belief in a religion. So whatever the materi-alism is that underlies science, it obviously does not preclude individual scientists from holding a variety of non-materialistic beliefs. This typically does not create problems as long as these individuals, qua scientists, operate within a materialis-tic framework when doing and communicating science.
As some philosophers have noted, the material of science is not well circum-scribed and has undergone dramatic changes. A world that consists of radiation, fields, quanta, and curved space was not part of the materialism of early scientists.
One could argue that the change in the material worlds implied by general relativ-ity and quantum mechanics constitute as dramatic a departure from the material-ism of previous scientific generations as that implied by psychic phenomena.
Although Carter and Dean Radin rant against the materialism of science, this materialism has changed dramatically and presumably will do so in the future. It is not a fixed, immutable belief system. However, and this is what Carter and Radin seem to overlook, the materialistic belief system of science has undergone these dramatic transformations in response to evidence that is rigorous, replicable, and irrefutable. This is how science works. If Carter and his fellow parapsycholo-gists put forth equally rigorous, replicable, and irrefutable evidence for something they call “psi,” the scientific community’s materialism will change yet again to accommodate this new input.
Carter’s mantra, echoing that of many of his fellow parapsychologists, is that, in fact, the parapsychologists have provided just such irreproachable evidence for the reality of psi. They assert that the scientific community has not recognized this because of an inherent bias against paranormal claims. If, as Cater maintains, the scientific community treated parapsychology in the same way it treated other disciplines, it would long ago have accepted the reality of psi. To support this fan-tasy, Carter implies that skeptics, such as James Alcock and me, have deliberately selected and/or distorted the evidence to maintain their claims that parapsycho-logical evidence does not pass muster. Indeed, he accuses us of deliberately going out our way to demean parapsychology.
Sadly, his chapter is based on misrepresentations of the facts, accusations of biased and irresponsible behavior on the part of critics, and blatant failure to deal with the many legitimate arguments against the validity of the parapsychological claims. Before I explicate these points, I want to make a few comments about Carter’s argument that the real issue is that scientists and the critics have a world-view that cannot tolerate the possibility of non-materialistic alternatives (whatever they might be). He focuses on the alleged bias of critics and simply assumes, rather than demonstrates, that the parapsychological evidence is rock solid.
Despite our obvious disagreements, Carter and I have one thing in common.
We both use the history of science to illuminate our arguments. However, we differ in our reading of this history (or perhaps on what we read) and the lessons to be drawn. Carter is correct in asserting that scientists are biased against the claims for psi. He errs, however, in assuming that parapsychology is unique in this respect. A central feature of scientific inquiry is that scientists are biased against claims that are inconsistent with the current framework within which they are working. This was true for relativity, quantum mechanics, evolution by natural selection, N-rays, continental drift, and just about every other novel claim that was inconsistent with a current theoretical framework.
In many of these cases, solid, replicable evidence accumulated and the scien-tific community revised or adjusted its existing theories to accommodate this evidence. In other cases, such as the claims for Martian canals, N-rays, and mitogenetic radiation, the evidence, which at first seemed impressive, became inconsistent. With increasing numbers of failed replications, the claims of an anomaly were dismissed. In this respect, the claims for psi resemble those, say, for N-rays. At first, many successful papers were published on N-rays, especially by eminent French scientists. Other scientists were encouraged to investigate N-rays. As more and more scientists began working on N-rays, more and more reports were published of failed replications. Eventually, the scientific commu-nity relegated N-rays to the discard pile. In various domains of parapsychological inquiry a similar pattern is seen. At first there are many papers that claim “statis-tical significance.” Eventually, some of the original investigators along with new ones fail to obtain significant results. This “decline effect” is just one of the ways that inconsistencies plague lines of parapsychological research. Kennedy (2001, 2003) lists several others.
As I mentioned in my chapter, parapsychological claims resemble these other failed claims of anomalies in science in that the proponents of the claim defended the inconsistencies in terms of experimenter effects, non-conducive conditions, and the like. Carter is one of those writers sympathetic to parapsychology, who, along with Radin, argues that “consistent, replicable” evidence for psi exists. This claim, of course, flies in the face of those parapsychologists (as I discussed in my chapter) who argue that not only have parapsychologists failed in their attempts to produce consistent and replicable evidence for psi, but such evidence in principle cannot be produced! This is because, in their view, an intrinsic property of psi is that it actively evades scientific scrutiny (Bierman, 2001; Jahn & Dunne, 2008;
Kennedy, 2001, 2003; Lucadou, 2001).
I suspect that Carter, like many of his colleagues, uses the term “replicable” in a way quite different from how it is understood in orthodox science. Radin, among others, have maintained that the lack of replication of evidence for psi was more apparent than real. Because of low to moderate effect sizes, most psi experiments lack adequate power to detect a real effect. Indeed, the use of meta-analysis was seen as a way to overcome this defect. However, there now have been a number of failed replications of key parapsychological findings that had sufficient power.
The most visible one was the massive attempt to independently replicate the
key findings of the Princeton random event generator experiments (Jahn et al., 2000). Such striking failures cannot be brushed aside. As I have pointed out in my chapter and elsewhere, some replications that parapsychologists have claimed as successes were actually failed replications. The claims for success in these cases come about from a very lax standard for “success.” Because of the loose ties between theory and data, parapsychologists often are willing to claim as a successful replica-tion any outcome that is “significant,” even if the pattern of the outcome contra-dicts that of the original experiment.
My point is that, yes, scientists are biased against the claims for psi. And this is as it should be. Science has been successful just because it has been conservative.
It is suspicious of any claims that apparently violate expectations based on the current framework within a given area of inquiry. The claims for an anomaly in the orbit of Uranus, for example, were viewed with suspicion. Even more, the claims that the anomaly was due to a failure of Newton’s laws of gravity when applied to outer space were met with disbelief. After all, Newton’s mechanics had survived many previous challenges and had provided a host of striking successes.
The anomaly was resolved, and resistance to the proposed solution vanished in the face of good and replicable evidence for the existence of the new planet.
Scientists have at least two good reasons for maintaining a bias against claims for psi. Parapsychologists, along with others who have claimed the discovery of an
“anomaly,” imply that they have uncovered a meaningful discrepancy from what should be expected under an existing scientific framework. Urbain Le Verrier, for example, convincingly demonstrated that the orbit of Uranus departed in a small, but very reliable way from what was predicted under Newtonian mechan-ics. Le Verrier’s exhaustive re-analysis of all the data on the orbit of Uranus con-vincingly showed that the anomaly was real. He then provided an explanation that could be scientifically verified.
In those cases within science where an anomaly was claimed, the anomaly was depicted as a precisely delineated departure from a given baseline. The baseline in question was always a theoretical expectation within a more or less delimited area of science—planetary astronomy, energy physics, genetic biology, etc. Parapsy-chology stands out as an exception. Here the claimed “anomaly” is not a well specified departure from a theoretical prediction within a given domain of sci-ence. Instead it could be any departure from a generic baseline. The connection between parapsychological theory (which is also amorphous) and specific outcomes in psi research is such that the theory places no constraints on which statistical departures constitute evidence for psi and which do not. The parapsy-chologists have no disciplined way to even show that the statistical discrepancies in one experiment have any relation to the statistical discrepancies in another.
Nor has anyone reported a single case of a discrepancy within regular scientific research that can be attributed to something called “psi” (unless the parapsychol-ogists want to claim that every unexpected glitch in a scientific experiment is due to psi).
Such a lack of constraint between theory and data provide plenty of degrees of freedom to consider any departure from chance as evidence for psi. This helps
boost the illusion of many more successful outcomes than actually exist. It also provides justification for scientists to be suspicious of the claims for psi.
The second reason for being dubious is the issue of replicability. Many failed claims in science passed the first test of being based on a clearly defined discrep-ancy from a theoretical prediction with a given field of science. However, they failed the second test in that the evidence supporting the claimed anomaly became inconsistent and could not be reliably replicated by independent experimenters.
Radin and Carter are among those writers who boldly declare that the evidence for psi is strong, lawful, and replicable. What they seem to have in mind is that in many areas of psi research a new experimental design apparently yields several studies that produce statistical significance (regardless of whether the internal pat-terns of outcomes replicate). As Bierman, Kennedy, and other parapsychologists point out, the problem is that over time the experimental design no longer shows consistent results and, in many cases, no longer can yield significance.
As I keep emphasizing, regular science has a stricter standard for replicability.
For one thing, a claimed anomaly, as already discussed, must be a clearly defined pattern of deviation from a theoretical prediction. Clearly, parapsychology can-not meet this standard. Along with this first condition, the clearly defined pattern must be able to be replicated by independent investigators given adequate research design and power. Parapsychology has also failed to meet the second con-dition. Retrospective demonstrations of statistical significance of combined effect sizes in meta-analyses of past experiments are insufficient. Even if the underlying assumptions of meta-analysis were met—which they decidedly have not been—
it is a retrospective procedure. The idea of replicability within science is a predic-tive one—given adequate conditions and power, can an experimenter obtain the predicted result? Again, the several examples in which this has been attempted in parapsychology have failed.
Consider this sobering fact. Every discipline that claims to be a science can pro-vide hundreds of examples of what Thomas Kuhn called paradigm1experiments (Kuhn, 1970). These are experiments that introductory textbooks and laboratories in each discipline can assign to their students with the strong expectation that the students will obtain the predicted results. In psychology, a discipline with which parapsychologists often favorably compare their discipline, introductory students can be assigned hundreds of paradigm experiments in perception, memory, learn-ing, decision maklearn-ing, and the like with full confidence that the students will obtain the expected outcome. Parapsychology stands alone as the only discipline claiming to be a science that has not one such experiment. This fact alone makes it clear that parapsychology is unique in lacking replicability.
Unfortunately, I have to conclude that Carter’s chapter comes close to con-sisting of an ad hominem attack against critics of parapsychology. His emphasis is on the alleged worldview that impels the critics to go to any lengths—includ-ing deliberate suppression of data. Indeed, there are, and there have been, vocal skeptics who have behaved in ways that might justify some of Carter’s concerns.
On the other hand it is a logical fallacy to dismiss a person’s criticisms on the basis of their alleged motivations and mindsets. Worse, attributing motivations
and worldviews to critics on the basis of flimsy gossip makes for misleading and irrelevant arguments.
Because Carter makes James Alcock and me the chief villains in his diatribe, I feel compelled to depart from the stance that I preach to others and try to fol-low in my own argumentation. I have always argued that the critics should focus on the issues and avoid personalities. My article on “Proper Criticism,” which was first published in 1987 and has been subsequently reprinted online, is just one example of my position (Hyman, 1987). I believe that my approximately 100 published critical assessments of parapsychology adequately demonstrate that Carter’s repeated attempts to caste me in the role of a bigoted fanatic whose mission is to suppress and destroy parapsychology have no basis. As I will point out, whatever Carter wants to say about Alcock and me, he cannot in good faith accuse us of not having done our homework. I have always carefully examined the best evidence for a parapsychological claim before providing a critique.
The reason I chose Alcock for the National Research Council (NRC) Committee was simply because he also is one of the few critics who conscientiously makes sure to examine the best evidence available that supports a parapsychologi-cal claim. Ironiparapsychologi-cally, such conscientiousness is glaringly absence in Carter’s attacks.
Carter begins his chapter with a quote from John Alexander that states that
“Hyman and James Alcock proceeded on an intentional path to discredit the work in parapsychology. . . What we may ask, are they afraid of? Is protecting sci-entific orthodoxy so vital that they must deny evidence and suppress contrary opinion?” Later in his chapter, Carter provides a lengthy quotation (460 words) from this same source (Alexander, 1989). This quotation gives at best a mislead-ing account of the NRC Committee’s treatment of parapsychology. Apparently, Alexander’s report is the main source of Carter’s account. It seems likely that Carter did not read either the NRC Committee’s report on the parapsychological research (Hyman, 1988) or Alcock’s commissioned paper (1988). If he had done so he would have realized that much of what he said is simply not true.
John Alexander played a limited role in the Committee’s work. In 1985, at the first meeting of the Committee on Techniques to Enhance Human Perfor-mance, Lt. General Albert Stubblebine III (retired) and then Lt. Colonel John Alexander briefed the Committee on potential applications and some research on the paranormal in the armed forces. Alexander claimed that he could provide the Committee with evidence, as well as a demonstration, of a parapsychological experiment that could be repeated on demand. He urged the Committee to visit San Diego to witness this demonstration. Alexander had been using Army money to support the research of Cleve Backster. Backster, who is a polygraph expert, had gained public attention in 1966 when he hooked up a polygraph to a philodendron plant and recorded a response that he claimed was similar to that of humans in an emotional state. Backster argued that the plant exhibited this emotional response when brine shrimp were either threatened or killed in an adjoining room. This work instigated a highly controversial movement dealing with “primary perception” in plants (e.g., Backster, 2003).
When the Committee held one of its meetings in San Diego in February, 1986, Alexander arranged for us to spend a day at the Backster Research Foundation.
Alexander and Backster informed us that Backster had devised a technique for recording electrical activity in leukocytes taken from a donor’s mouth. These leu-kocytes would subsequently show reactions to the donor’s emotional states, even if the donor were separated as much as a mile from the leukocytes. Backster showed us his apparatus and the data he had collected so far. He also attempted to demon-strate the phenomenon with a volunteer from our Committee. Suffice it to say, that neither Backster’s data nor the demonstration showed any evidence of a para-normal phenomenon. Not only did the apparatus suffer from inadequate shielding and other defects, but the apparent correlations between emotional states of the donor and the detached leukocytes seemed to be due to statistical artifacts and misinterpretation of the data.
We included a description of the Backster experiment in our report only because Colonel Alexander had insisted that the Committee should investigate
We included a description of the Backster experiment in our report only because Colonel Alexander had insisted that the Committee should investigate