Does IQ Predict Success? What the Research Actually Shows

What IQ reliably predicts

Academic performance: IQ correlates at r=0.5-0.6 with grades and standardized test scores. This is the strongest and most replicated finding in all of differential psychology. The relationship holds across cultures, age groups, and school systems.

Job performance: Schmidt and Hunter's landmark 1998 meta-analysis of 85 years of employment data found general mental ability (GMA) correlates at r=0.51 with job performance for complex jobs and r=0.23 for simple, routine jobs. The more complex the work, the more IQ matters.

Income: Each IQ point is associated with $200-600 more in annual income (Cawley et al., 1997; Murray, 2002). The effect compounds at the extremes - the top 5% of earners are disproportionately high-IQ. But the relationship is noisy; plenty of average-IQ individuals outperform their predictions.

Where IQ falls short as a predictor

Angela Duckworth's grit research (2007) found that self-reported grit predicted final GPA in West Point cadets better than IQ, and predicted advancement in the National Spelling Bee better than vocabulary scores. For long-term achievement, sustained effort may matter more than initial ability.

Leadership effectiveness correlates more strongly with emotional intelligence (EQ) than with IQ. A 2004 meta-analysis by Cote and Miners found that EQ predicted transformational leadership independent of IQ. Top leaders across industries tend to have high EQ but not necessarily top-percentile IQ.

Conscientiousness - being organized, reliable, and thorough - is the personality trait that most consistently predicts job performance and life satisfaction. Unlike IQ, it can be developed deliberately through habits and environment.

Famous failures of high-IQ groups

Long-Term Capital Management employed two Nobel laureates in economics and an average team IQ likely above 145. It required a $3.6 billion bailout in 1998 after catastrophically misestimating tail risk. Enron recruited heavily from top MBA programs - its leadership showed extreme overconfidence despite high measured intelligence.

These cases illustrate that high IQ combined with poor judgment, overconfidence, or weak risk management can produce worse outcomes than moderate IQ with good processes. Intelligence amplifies whatever tendencies are already present.

Success across the IQ range

The Terman Genetic Studies of Genius tracked 1,521 children with IQs above 140 from the 1920s onwards. While they had better-than-average outcomes on average, many had ordinary careers. Two children Terman rejected for the study - William Shockley and Luis Alvarez - both won Nobel Prizes.

Conversely, many highly successful entrepreneurs, artists, and leaders operate with average or slightly above-average IQs, compensated by domain expertise, social intelligence, and extraordinary drive. Richard Branson, who struggled in school and likely has dyslexia, built a $3 billion empire.