... Smart people have a problem, especially (although not only) when you put them in large groups. That problem is an ability to convincingly rationalize nearly anything.
Everybody rationalizes. We all want the world to be a particular way, and we all make mistakes, and we all want to be successful, and we all want to feel good about ourselves.
We all make decisions for emotional or intuitive reasons instead of rational ones. Some of us admit that. Some of us think using our emotions is better than being rational all the time. Some of us don't.