Does a high IQ guarantee success?
It does not. IQ predicts years of education, type of occupation and income on average, but the link with income is weak. In a 2007 meta-analysis, the correlation was 0.56 with education, 0.43 with occupation and 0.20 with income.
In this article
What did the research measure?
In 2007, sociologist Tarmo Strenze of the University of Tartu pooled the longitudinal studies on the topic: research that measured people's intelligence first and their success years later. Success there means three measurable things: education, occupational level and income.
| Outcome measured later | Correlation with IQ | Samples | People |
|---|---|---|---|
| Education | 0.56 | 59 | 84,828 |
| Occupation | 0.43 | 45 | 72,290 |
| Income | 0.20 | 31 | 58,758 |
These are corrected correlations, as the author reports them in Table 1 of the paper. All are positive: on average, people with higher IQ study longer, reach higher-level occupations and earn somewhat more.
What does a correlation of 0.20 mean?
That the link exists but leaves a lot of room for exceptions. A correlation goes from 0, no relationship, to 1, a perfect one. At 0.20 between IQ and income, there are many people with high IQ and low income, and many with average IQ and high income.
A quick calculation shows the size: 0.20 squared is 0.04. In statistical terms, IQ tracks about 4% of the variation in income among the people in these studies. The rest depends on other things.
Does IQ predict more than family background?
A little more, but not much. Strenze himself concludes that intelligence is a powerful predictor but, on the whole, not an overwhelmingly better one than parental socioeconomic status or school grades. In the same table, an index of parental socioeconomic status had a correlation of 0.55 with education, 0.38 with occupation and 0.18 with income.
Does the link change with age?
Yes, mainly for income. Measured at ages 20 to 24, the correlation between IQ and income is close to zero; at 25 to 29 it rises to 0.20, and at 30 to 34 it reaches 0.27. Early in a career, income depends little on IQ.
What does this say about your result?
That it describes a group tendency, not a destiny. A high result guarantees nothing, and an average result rules nothing out. That is why IQNorth presents the number as an educational estimate with a margin of error, and not as a prediction about your life. What the number says and what it leaves out is in What IQ is, and what it isn't.
Sources
- Strenze, T. (2007). Intelligence and socioeconomic success: A meta-analytic review of longitudinal research. Intelligence, 35(5), 401–426. Accessed Nov 5, 2026. https://doi.org/10.1016/j.intell.2006.09.004
- Neisser, U., et al. (1996). Intelligence: Knowns and unknowns. American Psychologist, 51(2), 77–101.
