Proof(?) of ESP
- View SourceNY Times
January 5, 2011
Journal's Paper on ESP Expected to Prompt Outrage
By BENEDICT CAREY
One of psychology's most respected journals
has agreed to publish a paper presenting what
its author describes as strong evidence for
extrasensory perception, the ability to sense future events.
The decision may delight believers in so-called
paranormal events, but it is already mortifying
scientists. Advance copies of the paper, to be
published this year in The Journal of Personality
and Social Psychology, have circulated widely
among psychological researchers in recent weeks
and have generated a mixture of amusement and scorn.
The paper describes nine unusual lab experiments
performed over the past decade by its author,
Daryl J. Bem, an emeritus professor at Cornell,
testing the ability of college students to accurately
sense random events, like whether a computer
program will flash a photograph on the left or
right side of its screen. The studies include
more than 1,000 subjects.
Some scientists say the report deserves to be
published, in the name of open inquiry; others
insist that its acceptance only accentuates
fundamental flaws in the evaluation and peer
review of research in the social sciences.
"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.
In an interview, Dr. Bem, the author of the
original paper and one of the most prominent
research psychologists of his generation, said
he intended each experiment to mimic a
well-known classic study, "only time-reversed."
In one classic memory experiment, for example,
participants study 48 words and then divide a
subset of 24 of them into categories, like food
or animal. The act of categorizing reinforces
memory, and on subsequent tests people are more
likely to remember the words they practiced
than those they did not.
In his version, Dr. Bem gave 100 college students
a memory test before they did the categorizing
and found they were significantly more likely to
remember words that they practiced later.
"The results show that practicing a set of
words after the recall test does, in fact,
reach back in time to facilitate the recall
of those words," the paper concludes.
In another experiment, Dr. Bem had subjects
choose which of two curtains on a computer
screen hid a photograph; the other curtain
hid nothing but a blank screen.
A software program randomly posted a picture
behind one curtain or the other but only
after the participant made a choice. Still,
the participants beat chance, by 53 percent
to 50 percent, at least when the photos being
posted were erotic ones. They did not do better
than chance on negative or neutral photos.
"What I showed was that unselected subjects
could sense the erotic photos," Dr. Bem said,
"but my guess is that if you use more talented
people, who are better at this, they could
find any of the photos."
In recent weeks science bloggers, researchers
and assorted skeptics have challenged
Dr. Bem's methods and his statistics, with
many critiques digging deep into the arcane
but important fine points of crunching numbers.
(Others question his intentions. "He's got a
great sense of humor," said Dr. Hyman, of Oregon.
"I wouldn't rule out that this is an elaborate joke.")
Dr. Bem has generally responded in kind, sometimes
accusing critics of misunderstanding his paper,
others times of building a strong bias into
their own re-evaluations of his data.
In one sense, it is a historically familiar
pattern. For more than a century, researchers
have conducted hundreds of tests to detect ESP,
telekinesis and other such things, and when
such studies have surfaced, skeptics have been
quick to shoot holes in them.
But in another way, Dr. Bem is far from typical.
He is widely respected for his clear, original
thinking in social psychology, and some people
familiar with the case say his reputation may
have played a role in the paper's acceptance.
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."
Many statisticians say that conventional
social-science techniques for analyzing data
make an assumption that is disingenuous and
ultimately self-deceiving: that researchers
know nothing about the probability of the
so-called null hypothesis.
In this case, the null hypothesis would be
that ESP does not exist. Refusing to give that
hypothesis weight makes no sense, these experts
say; if ESP exists, why aren't people getting
rich by reliably predicting the movement of the
stock market or the outcome of football games?
Instead, these statisticians prefer a technique
called Bayesian analysis, which seeks to
determine whether the outcome of a particular
experiment "changes the odds that a hypothesis
is true," in the words of Jeffrey N. Rouder,
a psychologist at the University of Missouri
who, with Richard D. Morey of the University
of Groningen in the Netherlands, has also submitted
a critique of Dr. Bem's paper to the journal.
Physics and biology, among other disciplines,
overwhelmingly suggest that Dr. Bem's experiments
have not changed those odds, Dr. Rouder said.
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.
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