It's not entirely just a heuristic, but does have a Bayesian interpretation in many circumstances. Looking at the study on judge's sentences before and after m

It's not entirely just a heuristic, but does have a Bayesian interpretation in many circumstances. Looking at the study on judge's sentences before and after meals, you wouldn't expect to see a giant effect, but seeing some kind of an effect is a priori plausible, since we know many people are irritable when hungry. When you see an unusually large effect size, it's often the case that there is a smaller effect, but you happened to get some extreme data. You definitely shouldn't jump to the conclusion that the effect size is large if you think it is a priori unlikely to be so large (unless you have very high statistical power). As you say, the results shouldn't be discarded, though. edit: If an effect is incredibly improbable (like a relation between country music and suicides), evidence can still sway the belief against it. However, extraordinary claims require extraordinary evidence.