For half a century, social psychologists have been trying to figure out the human gift for rationalizing irrational behavior.
This self-delusion, the result of what’s called cognitive dissonance, has been demonstrated over and over by researchers who have come up with increasingly elaborate explanations for it. Psychologists have suggested we hone our skills of rationalization in order to impress others, reaffirm our “moral integrity” and protect our “self-concept” and feeling of “global self-worth.”
If so, capuchin monkeys are a lot more complicated than we thought. Or, we’re less complicated. In a paper in Psychological Science, researchers at Yale report finding the first evidence of cognitive dissonance in monkeys and in a group in some ways even less sophisticated, 4-year-old humans.