When applied to people’s intelligence, the theory behind the bell curve says that most people will be average, with a small percent being top performers and a small percent being losers. But when it comes to performance, the truth is the bell curve only exists if you believe it does.

Robert Rosenthal and Lenore Jacobson showed this 50 years ago. In their famous study, they gave students IQ tests to predict their ability to achieve and then shared the results with their teachers. As expected, students who scored the highest had achieved the most at the end of the school year.

However, the IQ scores had actually been assigned randomly and had nothing to do with the students’ true potential. This became known as the “Pygmalion effect.”

There have been many studies over the years that support the conclusion that although formal intelligence might be distributed on a bell curve, the potential for achievement is not.

 …