Some people say that we learn best from our mistakes. But all of us know about people who never seem to learn from their mistakes. This failure to learn is most obvious with people who keep making poor decisions and lifestyle choices. The psychological explanations are many and complex.
For simplicity, let us restrict explanation to the world of education. Educational philosophy has changed a great deal in the 50 years since I was in school. Back then, for example, I had the highest grades in school, but many of my teachers went out of their way to cut me down a notch or two so I wouldn't get conceited. Aside from the debatable question of whether that worked, the point is that today, the educational establishment has the opposite philosophy. They tend to tell all kids they are smart. I have seen elementary schools where most students are selected as "Honors Students." I know college education professors who won't give anything less than an A. Why is praise so liberally applied? In part, the idea is to bolster student self-esteem. Also motivating teachers is the reluctance to admit that some kids are smarter than others. Equal outcome is the politically correct expectation. That's why we have the No Child Left Behind law. Everybody is supposed to succeed because all are presumed equal. Of course the reality is that this is a lie, and the only way everybody achieves the same is to lower the standards to the least common denominator.
Research clearly shows that whether students learn best from their mistakes depends on a student's self-perception. Research by Carol Dweck and colleagues at Stanford demonstrated that the students who are most likely to learn from their mistakes are those who don't think of themselves as smart as such but smart enough to get smarter. They have a "growth mindset," a belief system that they can get better if they will just invest the time and effort. In one of the group's experiments, half of the students were repeatedly praised for "being smart," and these students were not good at learning from mistakes. It is not clear why. Maybe they thought the problem was in the learning material, not in them. The other half of students were praised for effort and improvement and these students got better and made fewer mistakes. Several months later, all students repeated a standardized test, and the "smart" students' scores dropped 20%, while the "growth mindset" students scored 30% higher.
Jason Moser followed up this idea with an experiment in which subjects performed a tedious task in which some mistakes were inevitable. Those who did best at learning from the mistakes were those who believed most strongly that they could get better at this task and make fewer mistakes. Brain electrical recordings during the task revealed two electrical signatures of the mindset, the first being an error-related negative voltage about 50 milliseconds after an error occurred, and a second positive voltage up to about a half a second later. The size of this second signal correlated with how intensely the subject paid conscious attention and was distressed by the mistake. This second signal was larger in those subjects that were the best learners, and they made even fewer mistakes as the task was repeated.
Ego is probably a factor. The "smart" students may seem to have plenty of self-esteem, but apparently failure is too painful a challenge to their ego and they find ways to rationalize or dismiss the mistakes. Students with a growth mindset may have better self-esteem, because they accept the challenge to their ego, and believe they can get better, which usually becomes a self-fulfilling prophecy.
A little humility is a good thing. Most of us, even the smartest, have a lot to be humble about. There is even a book on the subject, "Why Do Smart People Make Such Stupid Mistakes."
3. Merrington, C. (2011). Why Do Smart People Make Such Stupid Mistakes, St Albans, Herts, United Kingdom: Ecademy Press.