If you follow trends in psychology, you know that Freud is out and Darwin is in. The basic idea of “evolutionary psych” is that our brains are exquisitely designed to help us cope with our environment—but unfortunately, the environment they are designed for is the one we evolved and lived in for the past two million years, no the alleged civilization we created just a couple of centuries ago. We are, all of us, hunter-gatherers lost in the big city. And therein, say the theorists, lie the roots of many of our bad habits. Our craving for sweets evolved in a world without ice cream; our interest in gossip evolved in a world without tabloids; our emotional response to music evolved in a world without Celine Dion. And we have investment instincts designed for hunting mammoths, not capital gains.

Paul Krugman, The Great Unraveling, New York, 2003, p. 31