Are Cornell Students Psychic?

In a series of experiments, Cornell psychology professor? Daryl Bem has demonstrated “numerous ‘retroactive’ psi effects – that is, phenomena that are inexplicable according to current scientific knowledge” among hundreds of Cornell students. As the BPS Research Digest summarizes: “Take priming, the effect whereby a subliminal (i.e. too fast for conscious detection) presentation of a word or concept speeds subsequent reaction times for recognition of a related stimulus. Bem turned this around by having participants categorize pictures as negative or positive and then presenting them subliminally with a negative or positive word. That is, the primes came afterwards. Students were quicker, by an average of 16.5ms, to categorize negative pictures as negative when they were followed by a negative subliminal word (e.g. ‘threatening’), almost as if that word were acting as a prime working backwards in time.” Bern suggests the explanation may lie in quantum effects: “Those who follow contemporary developments in modern physics … will be aware that several features of quantum phenomena are themselves incompatible with our everyday conception of physical reality,” Bern writes. “Many psi researchers see sufficiently compelling parallels between these phenomena and characteristics of psi to warrant considering them as potential candidates for theories of psi.” [%comments]


A more honest and accurate reporting of this story would be that Bem has found a small (1.7% to 3%) effect that seems to not be due to chance alone. He then attributes this effect to "psi," specifically precognition. Given that there is no plausible mechanism for these psi effects, it would be much more reasonable to attribute the small effect to poor study design.

(Bem does claim that quantum mechanical effects may play a role, but this is pure speculative bunk. No coherent QM effect has ever been observed in a system as large and complex as the human brain...and no current theory within QM predicts the possibility of any such effect.)

Finally, an attempt to replicate a portion of Bem's study has already been performed and shows no effect:

As Thomas Paine said:

"We have never seen, in our time, nature go out of her course. But we have good reason to believe that millions of lies have been told in the same time. It is therefore at least millions to one that the reporter of a miracle tells a lie."


Pup, MD

Quantum physics must be the least likely explanation possible for this imaginable.

Ian Callum

This type of result raises issues similar to the quantum measurement problem in physics.


Handy rule of thumb: When somebody invokes quantum mechanics as an explanation, and that person is not an actual physicist discussing a painstakingly crafted and executed experiment with quantum states...'s a near certain bet they have no idea what they are talking about.

This research is (a) a brilliant experimental concept and (b) fascinating if true, but there is still a long way to go and other researchers have already started to find potential flaws in some of the methodology.

But either way, one thing I will predict right now with great certainty: Quantum mechanics has nothing to do with this.

Quantum effects simply cannot persist for long enough or become large enough in a "noisy" environment to affect the complex and distributed brain functions involved in deciding, for example, whether a word is "negative".

Psi researchers love to draw analogies with QM, but analogies are not science... and in fact the analogy is generally no deeper than "quantum mechanics is contrary to intuition, and psi is too, so since quantum mechanics is true, psi might be too.



My heuristics say that this is pseudoscience. If extraordinary claims require extraordinary evidence, I'd say this is merely decent evidence.

Already, an attempt to replicate some of the results has failed:

Thomas Doggette

What happens when you repeat it, determining randomly *after* the word what the "post-primer" is?


The stop watch was miscallibrated.

Ian Kemmish

On the other hand, if they were capable of understanding QM, they probably wouldn't have embarked on careers as psychic researchers.

Peter R

A good Bayesian response/destruction of this:

Eric M. Jones

No, but a degree from Cornell just declined in value a whole lot. The paper leaves out way too many details to guess where the problem is. Extraordinary claims demand extraordinary proof.

Call James (the Amazing) Randi, he'll give the professor a million dollars if the data is correct. That's why it isn't true:

Paul Clapham

Well, it could be because the two stimuli are processed by different parts of the brain at different speeds, so that the end result appears counter-intuitive.

Or it could be quantum mechanics. (Insert Twilight Zone music here.) But for my money it looks more like special relativity. Remember (or at least those of you who passed your relativity course as a physics undergrad, remember) that it's possible for two observers to disagree about the order in which two events in space-time occurred.


Extraordinary claims don't require extraordinary proof. They just require SOME proof.


Explaining some seemingly magical phenomenon away by claiming some piece of quantum mechanics is at work fits in the same basket as the phrase 'removing toxins' in pseudo-health care circles. Scientific sounding, but far from scientific.

Nevertheless, even if it's bunk, I appreciate the creativeness of the original postulation and subsequent attempt at testing it's veracity.


The obvious question is: what happens if you pick out the prime, but than never show it to the subjects, do you still get an increase in reaction speed? Maybe the data isn't traveling back in time, maybe the subjects are just picking up psychic signals from the computer?

Of course that hypothesis is just as terrible as the published theory, if you're going to put forth a supernatural explanation you also have to have a control group for other possible supernatural causes.

Maybe there are a lot of witches at Cornell and they're skewing the results. I'd imagine this would involve throwing water on the subjects - which would at least be more entertaining.

The point is that if you're going attribute results to supernatural causes you should at the very least take in to account the possibility of other supernatural causes, and control for them in your experiments, instead of just focusing on your pet theory.



I'm reminded of one of my favorite physics experiments back in high school, in which we dropped two items and timed how long it would take for the items to land. Our timing device was in no way driven by human response time to rule out any possibility of error due to the time required to hit a stopwatch.

In our experiment, the 1 kg weight consistently took more time to hit the floor than the 3 kg weight, which took more time than the 10 kg weight. My lab team immediately and proudly reported that our experiment had falsified the theory that acceleration due to gravity was a constant, thus making Galileo incorrect.

Needless to say, our physics teacher asked us to go back and explain why this particular experimental error showed up in our results.


I'm not holding my breath for independent verification of this study result.


Not so fast!

If you show a picture of a bright-eyed, smiling baby, then follow that with the subliminal message of "threatening"...YET the students defined that picture as negative before the word showed, then, yeah, it'd be interesting.

But if the visual was indeed negative, say a picture of Hitler, and then the students assigned it as negative before the word showed...well, that's no big deal, is it?

It depends on the visuals and words. If they are truly contrary to one another, and students are going with that before the word shows, then we have something to discuss. Otherwise, no.

Scott W. Somerville

It's not IMPOSSIBLE for this to be a quantum effect... but it's the least likely explanation. I'd go with Sherlock Holmes on this one... let's rule out all the impossibles before we latch onto something that improbable.

(Full disclosure: I fully expect researchers will find more and more "future causes the past" phenomema over time, but human subjects are prone to so many kinds of other effects that they make lousy test subjects for quantum experiments.)


For what it's worth, apparently Dr.Bem did his undergrad work in physics (50 years ago).
But misinterpreting results like this gives statistical significance tests a bad name.


Thanks. I needed a laugh today.

Bad science & bad statistics: two of my favorite things!!