Bayesian Analysis of Overprediction of Insanity
Decision-making under uncertainty is visualized as a two-action game against nature. The psychiatrist is the player and has two actions from which to choose: predict violent behavior or predict sanity. The two states of nature are (i) the accused is in fact guilty and (ii) the accused is in fan innocent. The psychiatrist acts as if he evaluates a loss function which is such that overprediction of violent behavior is the natural consequence of a rational person who wishes to minimize his personal risk. Society's loss function, however, differs from the psychiatrist's loss function to such an extent that a rational society would want to underpredict violent behavior in order to minimize the risk of false confinements. It is suggested that the player of this game (the psychiatrist) has been ill-advisedly chosen.