A review by davidr
How We Decide by Jonah Lehrer

5.0

This is one of the most entertaining "pop-psychology" books that I've read. It is filled with anecdotes and stories that illustrate the main point of the book: the emotional side of our brains makes our decisions for us, and the rational side of our brains helps justify our decisions. Sometimes, depending on our rational thoughts can get in the way of making good decisions, and can actually be a detriment. A good example is the physicist who got interested in playing poker professionally. He understood all of the probabilities very well, and did OK in the poker tournaments--up to a certain point. But he could not progress further, until he learned how the emotional side of his brain was needed in poker. Then he became a world-class poker player.

The book contains some incredible stories about people who are in imminent danger; an airplane pilot faced with the loss of all hydraulic power in his DC10, a group of firefighters trapped by a wildfire advancing toward them at 30 mph. They stopped rationalizing their situations, and started thinking intuitively, in order to survive.

Too much information can impede good judgment. Several psychology studies are described, where a little bit of information leads to a good judgment--say, investing in stocks, or accepting applicants to college--but a lot of information leads to a poor judgment. The reason is that our rational brains are limited by how many pieces of information we can juggle in our minds simultaneously. We find it difficult to consciously sort out which information should be given greater weight in our decisions.

Other stories in the book show how people form a world-concept, and then choose to ignore overwhelming evidence that casts doubt on their concept. Sometimes we use the rational side of our brain to justify our disregard of the evidence.

This book is an easy, fun read; highly recommended.