Is Self-Knowledge Overrated?

DKahnemanMore on Kahneman from Jonah Lehrer in the New Yorker:

[T]here is a subtle optimism lurking in all of Kahneman’s work: it is the hope that self-awareness is a form of salvation, that if we know about our mental mistakes, we can avoid them. One day, we will learn to equally weigh losses and gains; science can help us escape from the cycle of human error. As Kahneman and Tversky noted in the final sentence of their classic 1974 paper, “A better understanding of these heuristics and of the biases to which they lead could improve judgments and decisions in situations of uncertainty.” Unfortunately, such hopes appear to be unfounded. Self-knowledge isn’t a cure for irrationality; even when we know why we stumble, we still find a way to fall.

Consider the story of Harry Markowitz, a Nobel Prize-winning economist who largely invented the field of investment-portfolio theory. By relying on a set of complicated equations, Markowitz was able to calculate the optimal mix of financial assets. (Due to loss-aversion, most investors hold too many low-risk bonds, but Markowitz’s work helped minimize the effect of the bias by mathematizing the decision.) Markowitz, however, was incapable of using his own research, at least when setting up his personal retirement fund. “I should have computed the historical co-variances of the asset classes and drawn an efficient frontier,” Markowitz later confessed. “Instead, I visualized my grief if the stock market … went way down and I was completely in it. My intention was to minimize my future regret. So I split my contributions 50/50 between bonds and equities.”

Football coaches have performed just as badly. Although it’s now clear that their biases have a meaningful impact—a coach immune to loss aversion would win one more game in three seasons out of every four—their collective decision-making hasn’t improved.

This same theme applies to practically all of our thinking errors: self-knowledge is surprisingly useless.