Thursday, 10 June 2010

Non-bayesean anecdote of the day

In the late 1950s, psychologist Milton Rokeach was gripped by an eccentric plan. He gathered three psychiatric patients, each with the delusion that they were Jesus Christ, to live together for two years in Ypsilanti State Hospital to see if their beliefs would change. The early meetings were stormy. "You oughta worship me, I'll tell you that!" one of the Christs yelled. "I will not worship you! You're a creature! You better live your own life and wake up to the facts!" another snapped back. "No two men are Jesus Christs. … I am the Good Lord!" the third interjected, barely concealing his anger.
In hindsight, the Three Christs study looks less like a promising experiment than the absurd plan of a psychologist who suffered the triumph of passion over good sense. The men's delusions barely shifted over the two years, and from an academic perspective, Rokeach did not make any grand discoveries concerning the psychology of identity and belief.
In Slate, via ALD.

I'm not sure the plan was so crazy, even in hindsight, despite it having not worked. Surely that it didn't work also tells us something; it just might be something that we already knew. Rational Bayeseans with common priors cannot disagree, so we know that these folks either are irrational or aren't Bayesean truth seekers. Given that they know that they're in a psychiatric hospital, each might expect that the others are not rational truth seekers and consequently wouldn't update their priors adequately based on each others' information; however, they ought also give the same weight to the chances that they're in the hospital for the same reason as the others. On the other hand, plenty of people not in mental hospitals have radically different beliefs about just who god is; it's just the ones that identify themselves as god that wind up in the hospital - they may consequently reasonably question whether those putting them in hospital were rational Bayesean truth seekers.

Cowen and Hanson, linked above, conclude that very few people indeed are meta-rational truth seekers.
If you and the people you disagree with completely ignored each other’s opinions, then you might tend to be right more if you had greater intelligence and information. And if you were sure that you were meta-rational, the fact that most people were not might embolden you to disagree with them. But for a truth-seeker, the key question must be how sure you can be that you, at the moment, are substantially more likely to have a truth-seeking, in-control, rational core than the people you now disagree with. This is because if either of you have some substantial degree of meta-rationality, then your relative intelligence and information are largely irrelevant except as they may indicate which of you is more likely to be self-deceived about being meta-rational.

One approach would be to try to never assume that you are more meta-rational than anyone else. But this cannot mean that you should agree with everyone, because you simply cannot do so when other people disagree among themselves.
Rational truth-seeking is hard, even for the folks who don't think they're god....

Update: I really should have titled this one "We've got the Non-Bayesian Jesus(es)"...

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