In the current issue of the Journal of Personality and Social Psychology, a respected publication of the American Psychological Association (APA), veteran psychologist and sometime psi researcher Daryl Bem has published an ambitious paper describing nine experiments which he claims demonstrate precognition, the ability to know the future – or perhaps, a phenomenon in which the future somehow appears to affect the present.
The paper has received a fair amount of attention in the short time since it has become public knowledge, and there is no shortage of discussion around the blogosphere and among other interested outlets, from Psychology Today to Wired magazine. Not the least of reasons why the paper is garnering such attention – the potential for shattering contemporary scientific knowledge notwithstanding – is the simple fact that a prestigious journal is publishing a paper about parapsychology at all, much less one in support of paranormal claims. Parapsychology hasn’t been in the news in any serious manner in quite a while – that is to say, outside of television screens and pop culture scenes, which both fuel and feed a gluttonous appetite for such fare, from dime-a-dozen talk-to-the-dead mediums to programs exploiting children by supposedly exploring their psychic abilities. (See: “Psychic Kids” on A&E for the most recent evidence that just when things seem to hit their lowest on the offensive and manipulative trash scale, someone finds a denominator a giant leap straight downward.)
Another good reason for the attention is that Bem has published his raw experimental data, allowing other researchers to readily attempt to replicate his results. See, for example, Richard Wiseman’s comments; Wiseman, among others, is already attempting such experiments:
http://richardwiseman.wordpress.com/2010/11/18/bems-esp-research/
Wiseman was also among the first to point out a potential flaw in the experimental protocol, in which judging of results was not entirely double-blinded, and experimenters were allowed to make potentially subjective judgments of and adjustments to the accuracy of subjects’ hits or misses. Daryl Bem responds preliminarily to Wiseman’s comments, on the same blog page cited above.
For Daryl Bem, this research marks another step in a long history of attempting to design and conduct research that might establish psi in the laboratory, at these kind of low but allegedly statistically detectable levels, rather than by way of the flashy super powers of metal benders and talk-to-the-dead mediums. You can readily learn more about Bem’s history concerning, for example, the ganzfeld experiments, beginning in the 1970s, at sources like The Skeptic’s Dictionary; for example, see: http://www.skepdic.com/ganzfeld.html
Also at that site, amid other pertinent entries, see more about Bem and the “psi-conducive state”: http://www.skepdic.com/psi-conducive.html
And the Skeptic’s Dictionary entry on “precognition” now includes an aggressively skeptical update concerning Bem’s new paper, where the discussion in the readers’ comments section makes for useful reading (almost a paranormal event in itself):
http://www.skepdic.com/precog.html
Around the blogosphere, there are some handy summaries of Bem’s current paper for casual bystanders:
At Wired: http://www.wired.com/wiredscience/2010/11/feeling-the-future-is-precognition-possible/
At Psychology Today: http://www.psychologytoday.com/blog/the-social-thinker/201010/have-scientists-finally-discovered-evidence-psychic-phenomena?page=2
And I happened upon a commentary I enjoyed on a blog called “Notes from Two Scientific Psychologists,” Andrew Wilson and Sabrina Golonka [see: http://psychsciencenotes.blogspot.com/p/about-us.html]. Appropriately skeptical about Bem’s claims, these bloggers make the point that the analytical responses to Bem’s paper represent “the level of methodological scrutiny every paper should receive, and not just the ones you think are crazy: the ones you like and rely on for your own work should get a good working over like this too …”
However, be forewarned that the blog entry at Psychology Today (link cited above) is a little, uh … “trippy” (to use a phrase invoked therein) – the moment you start seeing quantum mechanics referenced as an explanation for psi, your best choice is to move on and find something actually substantive. The blog post there does raise an important issue, however, namely that of small effect sizes, albeit that it attempts to then summarily discount the issue and grasp at protective excuses for Bem:
… small effect sizes are not that uncommon in psychology (and other sciences). For example, on average, the Bem studies showed an effect size of .20 (out of a possible range of 0-1). Although that is fairly small, it is as large as or larger than some well-established effects, including the link between aspirin and heart attack prevention, calcium intake and bone mass, second hand smoke and lung cancer, and condom use and HIV prevention (Bushman & Anderson, 2001). And as Cohen has pointed out, such small effect sizes are most likely to occur in the early stages of exploring a topic, when scientists are just starting to discover why the effect occurs and when it is most likely to occur.
But this weak defense actually points to the most important questions that need to be asked about Bem’s claims (after, of course, we accumulate enough failed replications …). First, small effect sizes are also likely to occur in paranormal claims, which then invariably vanish once protocols are tightened, experiments refined, and replications attempted. This is why, more than 150 years after the birth of parapsychology as an alleged science, psi remains a chimera. Even in so-called “soft” sciences – psychology and social sciences as opposed to “hard” sciences like chemistry and physics – there are thousands of paradigmatic experiments, experiments that an undergraduate student in Psych 101 can execute and successfully replicate well establish results. Yet so far the number of such readily repeatable experiments with consistently reproducible results established in the field of parapsychology have, at latest count, reached the astonishing total of – wait for it! – zero.
But let’s also consider Psychology Today’s well-asked and poorly answered nod to effect size. Our new friends (well, new to me at least) at Two Scientific Psychologists put it succinctly, pointing out that:
… there's simply no effort to propose a mechanism that might support such an outrageous claim (and no, 'quantum mechanics' is not a mechanism). Bem explicitly states that coming up with a mechanism isn't his job and he's just 'reporting the data'. But this is precisely the problem with psychology right now - not enough theory - and the links below that talk about the analysis problems with this paper (and all statistical testing in the social sciences) make good points about the fact that statistical testing in the absence of a clear theory which includes mechanisms is effectively a fishing trip.
In other words, there might be small effects in support of “the link between aspirin and heart attack prevention, calcium intake and bone mass, second hand smoke and lung cancer, and condom use and HIV prevention” … but there are also proposed and plausible mechanisms.
Which brings us to the reason – the very good reason – why at the moment, we should be highly skeptical of Bem’s claims, and why “small effect” also effectively describes the degree to which I am disturbed about the implications of his latest work. As Skeptic’s Dictionary points out in its response to a reader’s comments [HERE: http://www.skepdic.com/comments/precognitioncom.html]:
I might add that without a plausible mechanism for how things that haven't happened yet can cause things to happen now, it will be very difficult to design an experiment that could falsify the precognition hypothesis.
More importantly, these tiny effects are used as a basis to claim evidence for the paranormal largely based on the so-called “psi assumption,” i.e., “any statistically significant deviation from chance performance would be taken as evidence of psi.” [See: http://www.skepdic.com/psiassumption.html]. And further:
The assumption that any statistical deviation from chance is evidence for telepathy is highly controversial, and often compared to the God of the gaps [see: http://en.wikipedia.org/wiki/God_of_the_gaps] argument. Strictly speaking, a deviation from chance is only evidence that either this was a rare, statistically unlikely occurrence that happened by chance, or something was causing a deviation from chance. Flaws in the experimental design are a common cause of this, and so the assumption that it must be telepathy is fallacious. This does not rule out, however, that it could be telepathy.
And so, as we wait for the sun to settle on failed replications, and watch as parapsychology eventually moves on to its next ephemeral and oh-so-temporary claim of the day, I will leave you with Professor Ray Hyman’s remarks, taken from a 1995 paper addressing problems, failures, and accomplishments of modern parapsychological research:
[A]cceptable evidence for the presence of anomalous cognition must be based on a positive theory that tells us when psi should and should not be present. Until we have such a theory, the claim that anomalous cognition has been demonstrated is empty.
Goodnight, Dr. Bem, wherever you are. I have a prediction about the outcome of attempts to replicate your work – and I don’t need to be psychic.
Jamy Ian Swiss is a magician, author, speaker, and longtime skeptical activist. He serves as Chairman of the Advisory Committee to the President of the James Randi Educational Foundation.