Okay, not really on psychic powers, but on precognition. Last October I posted about Daryl Bem’s paper in the Journal of Personality and Social Psychology, “Feeling the future: Experimental evidence for anomalous retroactive influences on cognition and affect,” (download a preprint on his webpage). I summarized its results as follows:
The paper purports to show that a choice that you make in a computer test can be influenced by stimuli you receive after you’ve already made the choice. This implies you have some way, consciously or unconsciously, of detecting things that haven’t yet happened.
I also mentioned some criticisms of these results by others; and many of the hundred-odd comments were also critical.
Yesterday’ss New York Times reports a strong backlash by scientists about the paper.
“It’s craziness, pure craziness. I can’t believe a major journal is allowing this work in,” Ray Hyman, an emeritus professor of psychology at the University Oregon and longtime critic of ESP research, said. “I think it’s just an embarrassment for the entire field.”
The editor of the journal, Charles Judd, a psychologist at the University of Colorado, said the paper went through the journal’s regular review process. “Four reviewers made comments on the manuscript,” he said, “and these are very trusted people.”
All four decided that the paper met the journal’s editorial standards, Dr. Judd added, even though “there was no mechanism by which we could understand the results.”
But many experts say that is precisely the problem. Claims that defy almost every law of science are by definition extraordinary and thus require extraordinary evidence. Neglecting to take this into account — as conventional social science analyses do — makes many findings look far more significant than they really are, these experts say.
“Several top journals publish results only when these appear to support a hypothesis that is counterintuitive or attention-grabbing,” Eric-Jan Wagenmakers, a psychologist at the University of Amsterdam, wrote by e-mail. “But such a hypothesis probably constitutes an extraordinary claim, and it should undergo more scrutiny before it is allowed to enter the field.”
Dr. Wagenmakers is co-author of a rebuttal to the ESP paper that is scheduled to appear in the same issue of the journal.
Wagenmakers commented on my post and gave a reference to his own paper rebutting that of Bems.
The report goes on:
Peer review is usually an anonymous process, with authors and reviewers unknown to one another. But all four reviewers of this paper were social psychologists, and all would have known whose work they were checking and would have been responsive to the way it was reasoned.
Perhaps more important, none were topflight statisticians. “The problem was that this paper was treated like any other,” said an editor at the journal, Laura King, a psychologist at the University of Missouri. “And it wasn’t.” . .
. . . So far, at least three efforts to replicate the experiments have failed. But more are in the works, Dr. Bem said, adding, “I have received hundreds of requests for the materials” to conduct studies.
I’ll bet big bucks that the effect vanishes, simply on the grounds that a mechanism for precognition seems unlikely. Perhaps the paper did deserve more thorough reviewing given its controversial nature, but the truth will out. And in the the advocates of precognition will be on even weaker ground.