(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 Dupré’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 Dupré 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.