In psychology, brilliant theories are cheap. People like to think of the field advancing thanks to some thinker’s startling new insight, but that’s not how it usually works. Coming up with ideas isn’t the hard part. Everyone has a pet theory for why we do what we do, which is why psychologists get sick of hearing their discoveries dismissed with “Oh, my grandmother knew that.” Progress generally comes not from theories but from someone finding a clever way to test a theory, as Walter Mischel did.
