Sunday, February 27, 2011

Do winners wear red? Does the truth wear off?

Last week I had to go to three meetings in a row so I wore my red sweater. A non-sequitur, you say? Well, maybe, but I had a theory. Based on this article in Nature, I had decided that wearing red would enhance my performance in conflicts, which I pessimistically assumed would arise in these meetings. Later in the week, I had a meeting where I didn't at all get what I wanted and I attributed it to the blue (loser) sweater I wore that day. Then I heard from my friend Sui Sui, international business professor at Ryerson, that the Nature study had been debunked. In the 2008 Olympics it turned out that the blue-shirted athletes won more often. And in the 2004 Olympics (the source of the data used in the Nature paper), it now appeared that the shirt colour allocation was not really random.

This brought to mind a very interesting article I read last month in the New Yorker, titled "The Truth Wears Off" by Jonah Lehrer. The author describes a variety of effects that were first estimated as being quite strong but were subsequently shown to be weak or non-existent. He attributes the tendency of "decline" to three main forces.
  1. Publication bias: In order to get published your paper needs to have strong, significant results.
  2. Selective reporting: Scientists screen their own work, tossing out results that don't fit with their priors.
  3. Study-level random effects. Although Lehrer doesn't really nail this point, I think what he is getting at is that the significance levels in studies are calculated as if every observation in the study is independent. But what if the "apparatus" used to conduct the multiple measurements has a problem? Then over and over again it will give similar results. If the flaw is random, it doesn't bias the result up or down but it does bias the significance levels so we think that we have something when we don't. In the case of the red-shirt study, there seems to have been something about the 2004 Olympics that tilted contest victories towards red shirts but it was not an enduring effect (i.e. not truly biological or cultural, say) so it didn't show up in the 2008 replication.

Saturday, February 05, 2011

Mental virtue

In the January 17 issue of the New Yorker, David Brooks has a very nicely written summary of work in psychology and social science title "The Social Animal." He uses the device of a composite character named Harold to convey the work and this is somewhat annoy (especially at the beginning and end where there seems to be some kind of light satire that isn't particularly amusing) but it works very nicely in the parts about human spouse-selection.

I have removed the "biography of Harold" aspects from one part of the article I found very insightful.

There is an important distinction between mental strength, which is the processing power of the brain and mental character, which are the cognitive virtues that lead to practical wisdom. The four virtues are:
  1. Collect conflicting information before making up your mind.
  2. Calibrate your certainty level to the strength of the evidence.
  3. Endure long stretches of uncertainty while waiting for an answer to become clear.
  4. Correct for your own biases.