Adaptive innaccuracy

While on a recent run (!), I was listening to the well-done Sipur Yisraeli podcast, which is modeled after the PRI radio show This American Life. One section talked about the human ability to estimate or predict ability. When people registering for a course are asked to estimate whether they will be in the top 5% of the class, they do a relatively good job— not perfect (some say they will and don’t; some say they won’t and do)—but not much more than 5% answer yes. However, when they ask whether student expected to be in the top half of the class, which should happen to about half of the folks, 70-80% said yes. Is this over-estimation? The same happened when people were asked to estimate how other people saw them in terms of attractiveness and intelligence—people all overestimated their appeal to the people they knew. One group, however, saw things more accurately: those who were depressed. In other words, understanding one’s limitations is associated with actual inability to function. So that 70-80% is adaptive. Apparently people wouldn’t sign up for a class if they thought they weren’t going to do better than average. We have to be overly optimistic or we wouldn’t do anything. Arrogance, or poor statistical ability, is, in some cases, desirable.