Evolutionary psychologists argue that we can understand the workings of the human mind by investigating how it evolved. Much of their research focuses on the past two million years of hominid evolution, during which our ancestors lived in small bands, eating meat they either scavenged or hunted as well as tubers and other plants they gathered. Living for so long in this arrangement, certain ways of thinking may have been favored by natural selection. Evolutionary psychologists believe that a lot of puzzling features of the human mind make sense if we keep our heritage in mind.

The classic example of these puzzles is known as the Wason Selection Task. People tend to do well on this task if it is presented