Evolutionary Psychology

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Robert Kurzban

The Evolutionary Psychology Blog

By Robert Kurzban

Robert Kurzban is an Associate Professor at the University of Pennsylvania and author of Why Everyone (Else) Is A Hypocrite. Follow him on Twitter: @rkurzban

Precognitive Adaptations -or- Can Extroverts Predict Where the Porn Will Be?

Published 15 October, 2010

In a paper listed as “in press” on Daryl Bem’s web page, to appear in the Journal of Personality and Social Psychology, he remarks that being able to “anticipate unpredictable erotic or negative stimuli before they occur…would be evolutionarily advantageous for reproduction and survival.” (p. 6)

No, you’re not reading that wrong. What he’s saying is that precognition would be adaptive, and particularly for sexy or scary things. I mean, it would be nice to know who was behind which door, The Lady or the Tiger, right?

Well, yes, and here are a few other things that would also be “evolutionarily advantageous for reproduction and survival:” The ability to fly. A portable perpetual motion machine. The ability to make everyone around you mistake you for a butterfly. (This would let you be sneaky.) The ability to cast Avada kadavra (which makes a deadly bolt of light). The ability to substitute your genes in someone else’s fertilized egg. (Right?) The ability to transform the pages of JPSP into something useful. And so on.

The fact that Bem uses an evolutionary justification to study psi is not really the big deal, of course. The big deal is that he’s studying psi.

In the first of nine experiments reported in the paper, subjects saw two curtains, and had to guess which one had a picture behind it, the other one being blank. In some trials, the pictures were erotic stimuli – people erotic, not squirrel erotic, for those of you thinking of a prior post – and some were just regular old test-for-psychic-powers stimuli. But, in a twist, the computer that placed the stimuli behind the curtain didn’t pick which picture would go where until after the subject guessed. This is sneaky because whereas subjects thought this was testing for clairvoyance – being able to ‘see’ what was hidden behind the curtain – it was, in fact – gotcha! – a test for precognition – being able to guess what decision the computer would make in the future.

Subjects were at chance for the regular stimuli, but they were above chance when the stimulus object was one of the erotic pictures, reaching 53.1% accuracy. (The regular pictures included romantic-but-not-erotic images, so the precognitive effect cannot be attributed to a long term mating stimulus; it has to be short term, i.e., raunchy.)

But wait, there’s more. In this study, as in some others reported in the paper, people who are more “stimulus seeking” – responding on the high end of the scale to questions like “I am easily bored” – showed a greater effect. In this case, the correlation between the individual difference variable and performance was .18. People above the median on this dimension were right – wait for it – 57.6% of the time on the erotic trials.

Ok, I’ll go ahead and say it: I don’t see anything clearly and obviously methodologically or statistically wrong here. Yes, my prior on this is a little bit (but not a lot) lower than my prior on the idea that there’s a mysterious resource that gets used up when you fight the temptation to eat a cookie – so, you know, it’s pretty darn low – but, you know, the world is complicated, and the data are the data. Maybe mysterious counterintuitive nonlocal quantum processes are at work here. Explaining one thing I don’t understand with another thing I don’t understand… sure, why not?

And, I’m sympathetic to Bem for several reasons. First, he gave a guest lecture in my social psychology class 20 years ago, and it was a great lecture, delivered while sporting a deeply adventurous neck tie, so I have empathy on both counts. Second, he’s been doing this kind of research for years, and he knows he’s been the punch line of countless jokes. (Having said that, on this list his entry has to do with self-perception theory, rather than something like, “I was able to foresee that I would be good at it” or something like that.) So, it’s hard not to admire his courage and tenacity. Third, unlike most papers in JPSP, he has a sketch of a functional explanation. I mean, he actually used it to make a pretty textured prediction: people would show the precognitive effect to the hard core stuff, but not the romance. That’s pretty good, right? Right?

Anyway, I get bored easily, so my psi is probably at the top of the scale, and I’m going to use my precognitive powers and go ahead and make a prediction: some blogger will use this article as evidence that evolutionary psychologists believe in genetic determinism.

  • http://ionian-enchantment.blogspot.com Michael Meadon

    Oh sigh. Why is JPSP (apparently going to) publish this??

    Your prior on psi should be a hell of a lot lower IMHO… http://www.skepdic.com/psi.html

  • http://evolvify.com Andrew

    I’m picking up on some mystical energy that’s congealing into a precognition that the “evolutionary psychology is a bankrupt endeavor” camp is going to have a field day with Bem’s article. Unfortunately, this is likely to be at the expense of EP – as a monolithic straw man (strawmanolith?) – rather than the research itself.

  • http://figleaf.blogspot.com figleaf

    Hey, and I have a theory that even more bloggers who think they’re pro evolutionary-psychology are going to have a field day with this. Expect at least one post containing the phrases “ancestors on the savannah” and “might well have” to reference this.

    That said, I suppose that if humans have inherent psi capabilities we would of course have obtained it through natural selection so some of the more interesting questions would be a) when exactly was this ability first selected for, b) do we share this characteristic with related species and if so what’s the most distant common ancestor of all species with this trait, c) what steps should be undertaken to identify the relevant sections of the genome, and d) how long before scamsters and trolls exploit this ability to overcome email and comment Captcha-style spam filters?

    One quibble: while I’m going to suspend judgment on psi as generously as you do I question whether the conditions of Bem’s experiment (testing psychic influence over randomly generated answers) support his conclusion (that psychically predicting answers would be reproductively advantageous. In fact, if I was designing an experiment to test either precognition or telekinesis(?) I’d want to make sure precognition wouldn’t confound the results when I was testing telekinesis and vice versa. Bem might want to rework his experiments and conduct new trials. (He might want to rework them anyway since his current results suggest psi actually exists.)

    figleaf

  • Robert Kurzban

    Thanks for the notes. A quick reply to figleaf. Bem has a discussion of the mechanism of randomization which is relevant to your remarks in the last paragraph. I think you’d find it interesting.

  • Pingback: Is The Exotic Erotic? Probably Not… | Pop Psychology

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