comment by Dmytry ·
2012-02-11T07:52:12.968Z · LW(p) · GW(p)
With regards to the comments here, a great deal of personal belief in morality of the world you live in, the fairness of the world, etc. relies on belief in good justice system, and those beliefs force you to believe justice system works better than it is and construct elaborate explanations of how it may be working well. It is not because the case is on dividing line between say 99% certainty, that you don't know what decision will court decide. The average people don't do probabilities that well as to estimate their uncertainty like that! We all know this.
Imagine you were dealing with a panel of chimpanzees or something else that's obviously dumber than you, deciding on the verdict while being demonstrably unable to comprehend much of the basic logic*, so that both sides HAVE to appeal to fallacies, and then sit nervous unknowing which fallacies latched onto the minds of jury better. The right side in principle could stick to logic alone but in any remotely complex case that is likely to fail.
*it suffices that average member of the jury has measured IQ of 100, with failure rate on the logic section of IQ test such that it implies inability to do much of even most basic reasoning. Nevermind probabilities. They can't do probabilities. Even for something as trivial as monty hall.
And you know what's worst? You can make a jury of PhDs, and the jury is still barely intelligent (even if more intelligent than average). Homo sapiens is barely intelligent, that's how things work - we evolved to be barely intelligent, at which point very rapid technological progress happened, and that was (in biological terms) very recently, and we are still barely intelligent.
Even worse still, there could be an utterly rational, effective agency at work as well. Selfish one. This agency determines that 1: thought-time expenditure on the process is not worth it (which leads to apparent stupidity well beyond one's stupidity on a test that might influence one's personal future), 2: if there is even 1% chance that the person is guilty of a major crime that can affect you, within even a large city, the personally rational, selfish action for you is to convict as the personal cost of convicting innocent is much smaller than personal cost of setting free the guilty (the social cost is however other way around). Even the perfect rational intelligence needs not arrive at a good judgement, nor to carefully listen and follow the argumentation, if that rational intelligence is selfish and optimizing it's use of computing time.
One should do scientific study on this. Do some experimental trials of the trial system, see if they can decide on correctness of proofs of theorems - two mathematicians represented by 2 barristers, one premise to a simple theorem, one mathematician trying to prove some fallacy, other trying to prove correct answer.
For me, lack of routine testing of the trial system in this fashion is evidence enough that it is probably not very effective - nobody tried to see what in practice does 'reasonable doubt' equate to (some juries may think its unreasonable to set free someone when there's doubts as to their innocence, some juries may get manipulated into setting free a certain murderer). It may be the best that we can do, but still be very bad.