Become a Better Guesser

The Economist reports on a better way to guess anything - just force yourself to make two guesses, and then average the two.

The two researchers asked 428 people eight questions drawn from the “CIA World Factbook”: for example, “What percentage of the world’s airports are in the USA?” Half the participants were unexpectedly asked to make a second, different guess immediately after they completed the initial questionnaire. The other half were asked to make a second guess three weeks later.

Dr Vul and Dr Pashler found that in both circumstances the average of the two guesses was better than either guess on its own. They also noticed that the interval between the first and second guesses determined how accurate that average was. Second guesses made immediately improved accuracy by an average of 6.5%; those made after three weeks improved the accuracy by 16%.

Even after three weeks, the result is still only one-third as good as the wisdom of several different people. But that this happens at all raises questions about “individuality” within an individual. If guesses can shift almost at random, where are they coming from?

Yet another strike against the utilitarian view of the world. People aren't optimizing utility functions inside their head, probably because optimizing functions is hard. Perhaps it is more like a slew of different guessing mechanisms and they pick between them heuristically. I can imagine that would be much easier to program. No calculus required.