It seems like a lot of people over think intelligence and success. Properly balanced or even an excess of serotonin and norepinephrine are what primarily ensures survival and procreation, which generally translates into happiness and sufficient wealth. Trying to measure and identify abstract cognitive ability like IQ tests do is almost somewhat of an autism spectrum-esque devotion. While some smart men and women may contribute greatly to society it's unusual for it to be a personal victory or indeed be as significant as dozens of better predictors of personal trajectory. Over-thinking things may even position excess cognitive function as a net negative drag on success.