Thursday, June 02, 2011

Runtime thoughts: Psychology: The Unnatural-est Science of All

Two of my goals this summer are to write more and to run more. Since I don't run with headphones, it gives me a good chance to turn over some ideas in my head. Even if no one reads them, I figured regular writing here after my runs would help me get the writing juices going.

One of the main ways that I think of science is that it is an unnatural way of thinking. What does this mean? The pieces of this I have previously thought of as the collection of shortcuts and biases that human thought entails. To take just one, once we get an idea, it is very hard to dislodge, because we only search for evidence that confirms our idea. Further, when we see evidence against our beliefs, we tend to minimize or ignore this evidence. This phenomena, called the confirmation bias shows how in our mind, we fudge the difference between facts, ideas and beliefs. It also makes science really hard to do, because science is supposed to be built on both positive and negative evidence. Science, while it is a search for truth, it is done by human brains, which aren't necessarily built to search for truth, but just to search for "close enough." This makes science very hard. The history of science is littered with examples where we thought we had the truth ("we are the center of the universe!" "the earth is only 4000 years old" "The ghost of falling made that apple fall" "look at the pretty phlogiston in the fireplace") only to be revealed as quite silly in retrospect.
Recently, there was a provocative paper in a great journal called Behavioral and Brain Sciences, by Hugo Mercier and Dan Sperber arguing that human reasoning evolved not to discover truth, but to persuade other people. The great thing about BBS is that they publish a long target article, followed by invited commentary from the community of experts. Basically the best, curated, edited comment feed in science. Of course, the bad thing about BBS is that they publish a long target article, followed by invited commentary from the community of experts, an issue is often over a hundred pages long. And, it is subscription only.
Here is an excellent summary by Chris Mooney over at Discover, and a great comment feed, with Mercier chiming in to argue with some philosophers (the puns, they make themselves!). They make sense of a number of the heuristics and biases, as well as some new experimental evidence in making this argument (too meta... I'm melting...). For me, this has interesting implications for the history and philosophy of science. Science progresses when it makes better predictions about the world (Galileo, Copernicus, Keppler, Newton ultimately won because they made more accurate predictions about the behavior of physical bodies). But human reasoning works by trying to convince other minds.
So why is psychology the most unnatural science? Because its predictions are not the behavior of falling bodies, or planets, but rather other people. If human reasoning evolved to convince the human mind, sometimes this can get in the way of understanding how the human mind works.

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