Experts try to be clever

One terrific chapter in Thinking Fast and Slow is 21, Intuitions vs Formulas. There Kahneman tells us a brutal unsettling truth, which is that for certain purposes in certain situations, algorithms do better than expert judgement. Thick detailed rich experiential knowledge does worse than a boring quick little formula. A psychologist called Paul Meehl made this claim more than 50 years ago and the research he inspired is still pouring out. Clinical psychologists don’t like the claim! (You can see the insurance people licking their chops, although Kahneman hasn’t mentioned that as far as I’ve read.)

This is about prediction, and for a moment I consoled myself with “oh well just for prediction…” but really, that won’t do. Prediction is the whole point of having a theory of mind, isn’t it.

It’s what people mean when they complain about “scientism,” I think – they’re resisting the horrible idea that a few questions could get a better handle on them than years of experience and conversation and deep thinking. We all want to be Isabel Archer, not a handful of ticked boxes.

Why are experts inferior to algorithms? One reason, which Meehl suspected, is that experts try to be clever, think outside the box, and consider complex combinations of features in making their predictions. Complexity may work in the odd case, but more often than not it reduces validity. Simple combinations of features are better. [p 224]

Isn’t that awful? That’s awful! All our beautiful complicatedness, tossed out the window because simple combinations of features are better. We’re not so complicated! The final scene in the movie, when the cops have shot us down, is no longer “I ain’t so tough,” it’s “I ain’t so complicated.”