Saturday, January 12, 2008

A map of human stupidity; why social science is useful   posted by Razib @ 1/12/2008 02:56:00 PM

Just a follow up on the post where many of the comments examined the utility of social science. I happened to walk by my copy of Judgment under Uncertainty: Heuristics and Biases today. Anyone who thinks that social science doesn't uncover "surprising" findings should check out this research program; it isn't a coincidence that Daniel Kahneman won the Nobel Prize in Economics in 2002. If the median human IQ was 4 standard deviations above what it is now there might be less concern about understanding the shape of human stupidity and how it manifests itself, but as it is we don't live in that world. From Adaptive Thinking: Rationality in the Real World:
...95 out of 100 physicians estimated the probability of breast cancer after a positive mammogram to be about 75%. The inference from an a disease, or more generally, from data D to a hypothesis H, is often referred to as a "Bayesian inference," because it can be modeled by Baye's rule...The important point is that Equation 1 [Bayes rule -Razib] results in a probability of 7.8%, not 75% as estimated by the majority of physicians....

To think in a Bayesian manner might not be natural, but neither is it cognitively taxing with some training (the equation isn't rocket science, though repeated utilization is probably essential to its practical value). Time is finite and human cognitive capacity and aptitude places constraints upon what is in the realm of the possible. By examining common cognitive errors and biases we can alert ourselves to the fallacies which we are all prone to. For a typical patient a new diagnostic device is a salient example of the utility of engineering; but if medical doctors routinely make statistically naive inferences because of the nature of human psychology then the utility of more precise and powerful devices is sharply reduced. Changes in the emphasis of topics in the curriculum of medical schools guided by psychological science is rather distant from the minds and experiences of the average person, but it may have a significant affect on our experienced utility.