Robin Hanson Responds

I recently posted criticisms of Robin Hanson and Kevin Simler's excellent new social science book The Elephant in the Brain. Hanson responds here. The response is short so I will reproduce it here:

The fourth blog review was 1500 words, and is the one on a 4-rank blog, by philosopher Tristan Haze. He starts with praise:

A fantastic synthesis of subversive social scientific insight into hidden (or less apparent) motives of human behaviour, and hidden (or less apparent) functions of institutions. Just understanding these matters is an intellectual thrill, and helpful in thinking about how the world works. Furthermore – and I didn’t sufficiently appreciate this point until reading the book, … better understanding the real function of our institutions can help us improve them and prevent us from screwing them up. Lots of reform efforts, I have been convinced (especially for the case of schooling), are likely to make a hash of things due to taking orthodox views of institutions’ functions too seriously.

But as you might expect from a philosopher, he has two nits to pick regarding our exact use of words.

I want to point out what I think are two conceptual shortcomings in the book. … The authors seem to conflate the concept of common knowledge with the idea of being “out in the open” or “on the record”. … This seems wrong to me. Something may satisfy the conditions for being common knowledge, but people may still not be OK talking about it openly. … They write: ‘Common knowledge is the difference between (…) a lesbian who’s still in the closet (though everyone suspects her of being a lesbian), and one who’s open about her sexuality; between an awkward moment that everyone tries to pretend didn’t happen and one that everyone acknowledges’ (p. 55). If we stick to the proper recursive explanation of ‘common knowledge’, these claims just seem wrong.

We agree that the two concepts are in principle distinct. In practice the official definition of common knowledge almost never applies, though a related concept of common belief does often apply. But we claim that in practice a lack of common belief is the main reason for widely known things not being treated as “out in the open”. While the two concepts are not co-extensive, one is the main cause of the other. Tristan’s other nit:

Classical decision theory has it right: there’s no value in sabotaging yourself per se. The value lies in convincing other players that you’ve sabotaged yourself. (p. 67).

This fits the game of chicken example pretty well. But it doesn’t really fit the turning-your-phone-off example: what matters there is that your phone is off – it doesn’t matter if the person wanting the favour thinks that your phone malfunctioned and turned itself off, rather than you turning it off. … It doesn’t really matter how the kidnapper thinks it came about that you failed to see them – they don’t need to believe you brought the failure on yourself for the strategy to be good.

Yes, yes, in the quote above we were sloppy, and should have instead said “The value lies in convincing other players that you’ve been sabotaged.” It matters less who exactly caused you to be sabotaged.

So Hanson paints me as a nitpicky philosopher, but nevertheless takes the points. He didn't mention the second point under the second heading, about theory of mind, which I think is maybe the most important. This omission better lets him get away with painting me as a nitpicky philosopher. But I am happy to see the response, and will not be daunted in making conceptual points that in fast-and-loose mode may seem like mere nitpicks.

What may seem like mere nitpicks at the stage of airing these ideas and getting them a hearing can turn into important substantive points in the context of actually trying to develop them further and make them more robust.