How Smart Do You Have to Be to Succeed?

Built around Lewis Terman's 1921 Stanford "Termites" study — which followed 1,528 of California's smartest schoolchildren for the rest of their lives — and creativity researcher Nancy Andreasen's framing, Clear explains Threshold Theory: above a modest intelligence baseline (roughly IQ 120), more IQ doesn't predict more creativity or success. The NFL offensive-lineman analogy: almost every NFL lineman is over 300 lbs, but past that threshold weight no longer predicts who is best. What matters past the threshold is deliberate practice and consistent habits.