Monday, October 19, 2009

Gene Callahan vs Evolutionary Psychology

So I recently had an uncharacteristic (and unpleasant) online altercation with one Gene Callahan about evolutionary psychology and, amazingly, whether Daniel Dennett should be taken seriously. I'm not blogging about this because it is inherently interesting (it's not), but because it nicely illustrates several common misconceptions about applying evolution to psychology and it reminds us that intellectual arrogance is a Bad Thing.

(I’d like to note before proceeding that it’s not as if I’m an uncritical fan of evolutionary psychology. There are, I think, numerous problems in the field, and the standards of evidence is far too often far too low. Some papers in the field are downright embarrassing (this one is the worst I’ve come across) and on my blog I have, among other things, excoriated Satoshi Kanazawa and critiqued Shermer’s application of evolutionary psychology to markets.)

Anyway, the saga in question started when a friend shared a blog post of Callahan’s on Google Reader in which he endorses John Dupr√©’s Human Nature and the Limits of Science, an uninformed screed against evolutionary thinking in psychology. (See this critique). I won’t have that much to say about the content of Callahan’s post – I will focus on his replies to my comments – but one remark about it is in order. Callahan:
I’ve just been re-reading John Dupre’s wonderful take-down of evolutionary psychology, Human Nature and the Limits of Science. Now, Dupre never disputes the obvious truism that, say, human ethics or religion evolved. But he notes that this is remarkably uninformative, since everything humans do so (sic) evolved, including their ability to write papers on evolutionary psychology!
This is somewhat cryptic and unclear, but straightforwardly interpreted, it is obviously wrong. To see why, consider the following. (I) Phenotypic structures (more precisely, biological processes) are either adaptations or the by-products of adaptations. (II) What distinguishes evolutionary psychology (at least of the Santa Barbara School) from sociobiology is the claim (see Tooby & Cosmides, 1987 [pdf]) that manifest behavior doesn’t evolve, modular information processing systems embedded in brains do. (III) Behavior is the result of a complex interaction between the environment and these information-processing systems; including direct environmental influences (e.g. drugs, brain injury) on the physical substrate of these information-processors. Observed behavior, then, is the product of the environment interacting with information processing mechanisms in the brain, and the brain is constituted of adaptations – structures that exist just because they increased fitness relative to alternatives in evolutionary history, including by producing or facilitating certain behaviors – or the by-products of such adaptations. It is therefore false that ‘everything humans do evolved’ since behaviors themselves don’t evolve, some behaviors result from by-products of evolution (not to mention pathology), and rapidly changing environments (the appearance of development of civilization, say) can interact with evolved psychological traits to produce novel behaviors (including writing papers on evolutionary psychology). The proposition that evolutionary psychology – broadly construed – is uninformative stems from these misunderstandings, and is indistinguishable from the crazy idea that evolutionary thinking generally is uninformative. Moreover, this claim is belied by the fact that we have discovered psychological abilities and traits (e.g., e.g.) that we didn't know about until we thought about human psychology from an evolutionary perspective.

On to the actual altercation… Callahan’s post rather annoyed me, so I left an aggressive – probably too aggressive – comment to the effect that (a) he is unqualified to have an opinion and (b) that he should read Daniel Dennett’s critique of the book. On reflection, I regret making point (a) as baldly as I did: I failed to err on the side of charity and to assume good faith. (Not to mention that I took Wikipedia’s word that he’s an economist, when he self-identifies as a philosopher, though I can’t help pointing out that he has a PhD in neither, so appending “in-training” is appropriate. Note: I don’t have a PhD either, so I happily concede I’m a wannabe cognitive scientist, not the real deal... yet). Understandably, Callahan didn’t take too kindly to my comment, so he replied aggressively himself, and then headed over to my blog and threw insults around on two of my posts: here and here. (Some tangential pedagogy: as I explained at length in my Fun with Fallacies post a while back, there is a difference between the ad hominem logical fallacy and mere insult. Callahan [I think, the comment was anonymous] calling me a “rude little punk”, for example, is not an instance of the ad hominem logical fallacy; even saying ‘you’re wrong and a rude little punk’ wouldn’t be fallacious. Only if he had said (or implied) ‘you’re wrong because you’re a rude little punk’ would he have committed the fallacy. There must be some inference drawn from some purported negative quality for the fallacy to occur, merely alleging someone has a negative quality is not itself fallacious, though of course it may be false or libellous).

Anyway, Callahan’s reaction to (b) was remarkable and illustrative: he dismissed Dennett’s critique of Dupr√© without reading it because he thinks Dennett’s work is a “rubbish heap”. Here’s what he said:
“Oh, and I’m not going to bother reading his [Dennett's] criticisms of Dupre. If I read several things by someone and they are universally rubbish, I really can’t be bothered to keep going through the rubbish heap. Anyone dull enough to have come up with the ‘brights’ idea really can be dismissed out of hand, don’t you think?”
Wow. The first sentence is the most interesting, but note that the second is factually inaccurate (Dennett endorsed the Brights idea – as did Dawkins – but neither came up with it) and invalid to boot. Worse, the suppressed premise (pdf) that would make the argument valid - ‘anyone who has one really daft idea can be dismissed out of hand (on all topics)’ – is clearly false. Granting for argument’s sake that the Brights idea was daft, it’s simply not true that if someone has one spectacularly bad idea that everything else they say will be wrong. Newton had silly ideas about alchemy and the Bible, but that doesn’t mean we can dismiss the Principia. Linus Pauling obstinately stuck to the incredibly implausible notion that ultra-high doses of Vitamin C can cure cancer, but that doesn't mean his work in chemistry was worthless. Physicists with idiotic philosophical or religious views are a dime a dozen, but that doesn’t mean their work as physicists is necessarily bad. Is it really that surprising that a philosopher and a ethologist, respectively, could be persuaded to endorse a bad marketing idea? If they did so would it mean that their professional work was all worthless?

Callahan’s first point in the above paragraph, though, is far more interesting and so worth looking into in a bit more detail. At first I thought he couldn’t possibly believe it – that perhaps he was just pissed off and said something silly in the heat of the moment – but he failed to back down in subsequent comments, so he really does seem to believe it. In summary, his argument is: ‘I read x% of Dennett’s work, what I read was universally rubbish, therefore everything by Dennett is rubbish’. (Callahan calls Dennett's work 'a rubbish heap', so he's not just making the more reasonable claim that 'he couldn't be bothered to read more of it'). This argument too is invalid - though of course I hardly expect people to make consistently logically valid arguments in blog comments. The point is that it contains at least one false suppressed premise, namely: ‘if I’ve read some proportion of a scholar’s work, I can judge all of it.’ This is both arrogant and false, the latter since for it to be true everyone would have to produce either consistent rubbish or consistent non-rubbish: it implausibly rules out a mixed bag. Newton, again, produced utter nonsense and sublime science, Jared Diamond wrote both Guns, Germs, and Steel (one of the best books of the 90s is my opinion) and Why is Sex Fun? (which was very bad indeed) and so on.

As a rule of thumb, I’d say that unless (1) you have read a good proportion of some scholar’s output, (2) you are qualified to judge all of it, and unless (3) everything you have read is entirely devoid of merit and without any redeeming qualities whatsoever, making a black-and-white inference about an entire corpus of work is just not reasonable. (People who make a priori unlikely claims in conflict with scientific consensus, show no interest in justifying their claims, and who lack relevant expertise can in most cases be dismissed out of hand. Sylvia Brown’s books, for example, are just not worth paying attention to. I take it as obvious that Dennett does not come close to fulfilling these criteria). Given how much Dennett has produced I’m willing to bet Callahan has not satisfied (1), and I have serious doubts about (2) since as far as I know not even Callahan himself claims to be a qualified cognitive scientist or philosopher of mind. More importantly, the prior probability of (3) is preposterously low and Callahan thus has a huge burden of proof to discharge. For him to do so he would not only have to demonstrate (preferably in a mainstream peer-reviewed journal) that, say, Consciousness Explained (CE) and Darwin’s Dangerous Idea (DDI) are rubbish but also explain why so many smart people – whether they agree with Dennett or not – were fooled into concluding the opposite. In other words, he must rigorously justify his initial contention not only that Dennett is wrong, but so wrong that his work is entirely worthless. And, if Dennett’s work is indeed utter rubbish, Callahan must explain why Dennett has been so influential: why, for example, CE has been cited 4700+ times and DDI 3000+ times. (Callahan objected to this point by saying it merely shows Dennett is famous, and mere fame presumably doesn’t track genuine merit. I responded that there’s a distinction between fame and influence: Dennett is both, Paris Hilton is only the former, Frege (say) is only the latter, and both Callahan and I are neither. Scholars just don’t see the need to read, let alone refer or respond to, utter rubbish so either Callahan is wrong or thousands of highly trained and really intelligent people are deluded. Of course, Callahan could be right, but I wouldn't recommend betting on it).

The moral of the preceding analysis, I think, is that intellectual arrogance is a very Bad Thing. I admit that I’m not exactly diffident, and that I have regularly fallen afoul of the principles I outline below. But I’m not nearly arrogant enough to dismiss whole disciples or declare all of an influential and prolific academic’s work utter rubbish. The common cause of such extreme beliefs, it seems to me, is overweening intellectual self-confidence, which is in turn arguably a product of an insufficient familiarity with one’s own fallibility. Cognitive biases and illusions are universal and ineradicable, the world is incredibly complicated and you can know only a fraction of the currently knowable. The mark of someone familiar with the above is scepticism, suspicion of bald assertions and hasty generalization, doubt, caution, a willingness to reconsider and admit error, and being scrupulously careful with facts and arguments. Callahan, it seems to me, fails to live up to these principles and the result is beliefs that, frankly, are downright idiotic. Or, as I put it rather more colorfully in my comments on his post, if these really are his beliefs, he should STFU, GTFO and take his FAIL with him. Srsly.

Of course, I could be wrong. Maybe I've been blinded by emotion, maybe I've been unfair, maybe I've misunderstood. If so, show me I'm wrong and I'll reconsider. Really.


  1. Lol. I thought of you when I shared it, something along the lines of, "Mike will find this entertaining." I found it momentarily interesting, then let go. Good that someone's putting up a fight though.

  2. Well said. I laughed a lot when one of the guys there said this guy was a 'philosopher of science.' Glad to learn that. lol The blog is a NYU blog. Is this representative of the work done at NYU?

  3. Michael, I think you should have another look at the first comment you posted. 'Aggressive' describes a point made forcefully; you were snide and condescending. 'Economist has opinion about book by philosopher on psychology' is a perfect example of an ad hominem attack, mistaken identity or not.

    I hope you don't think I'm being a prick. For what it's worth, I found Callahan unconvincing. As someone still learning about evolutionary psych, I would like to hear your response to Chomsky's critique that Callahan cited in the comments to his post.

    And perhaps this is disingenuous, but after all this, won't you assume that anything written by Gene Callahan is rubbish? From my corner- that would be the 'I know little about the topic at hand' corner- the whole saga seemed like two tribes lined up against each other, flung some shit, and beat some drums. No one listened, nothing was learnt, and nothing was achieved.

    Apologies for the rant.

  4. Simon: yeah, I thought you shared that for my benefit! :-)... If only I hadn't commented I would've saved myself some effort!

  5. Krisis: thanks! And I have no idea, but I sure hope not...

  6. Justin: yeah, I agree my first comment was quite nasty. (Which is what I meant by aggressive, but you're right that's not a particularly good word for it). But, erm... it's not ad hominem, it's a mere insult. Read my post! :-)... I explain what the difference between an insult and ad hominem is (in the "tangential pedagogy" bit).

    Would I dismiss anything Callahan has written? I hope I won't and I know I shouldn't. I mean, my RSS feed is already overflowing, so I'm hardly going to add his blog to my reading list. But I'd like to believe if I come across something else he's written I'd treat it on its merits. I probably will be somewhat biased, but I'll try not to be.

    As for Chomsky's criticism, yes, I think some evolutionary psychologists have fallen into that trap. But, remember, Popper famously said evolution itself is unfalsifiable, which it clearly isn'tt as long as it's done properly. ('Fossil rabits in the precambrian' and all that). Good evolutionary psychology similarly makes falsifiable predictions, then tests these. Have a look at the Sell et. al. paper I link to for an example.

  7. Michael, thanks. That definitely cleared things up for me. And I did read your post, and I still think it was ad hominem. Why did you bring up the fact that he was an economist, unless you were questioning his ability to participate in the argument?

  8. So... I thought about it a bit more and, yeah, I agree it was ad hominem. Nice example of not wanting something to be true influencing what I think is true...

    Now, that said, there is most certainly something to be said about expertise. Inductively (which is of course by definition invalid) someone who lacks expertise in a technical field (or one that is moderately complicated) is quite likely to get it wrong. As a general rule, if someone has strong opinions about some subject that runs counter to consensus and they lack relevant expertise - as I believe is true of Callahan - they are likely to get stuff wrong. (There is no consensus that EP is right, of course, but everybody worth taking seriously thinks the mind/brain evolved, and everybody worth taking seriously thinks evolutionary thinking is informative.) My frustration with Callahan was a manifestation of a general frustration with people having strong opinions outside their field. Especially so when these people express an extreme position in an arrogant way.

  9. Aha!

    I have decided to begin my seeding here. The internet has provided me with the opportunity meet practitioners of the philosophy of ridicule. There may be no defense but we can save ourselves time.