For predictions of the kind studied by Dunning and colleagues, and by Newton and colleagues (where subjects were asked to predict who would be most likely and who least likely to contribute to a food drive), the base rate, whether known or presumed, is the best basis for prediction. When the base rate is extreme, one can oppose it in one’s predictions only at one’s dire peril. And this is true even if the target is someone who the predictor knows well.
