Is personality a better predictor of important life outcomes than IQ?

Note: This is a section of a longer article. To go to the start, click here.

For the outcomes that we measured, mostly yes. We have asked our participants to report their a) highest level of education, b) high-school GPA, c) college GPA, d) personal income, d) household income, e) current happiness level (i.e., "Right now, at this very moment, how happy or unhappy do you feel?") and f) life satisfaction. For almost every outcome, personality was  a better predictor than IQ. In technical terms, five personality traits (openness, conscientiousness, extraversion, agreeableness and neuroticism) explained more variance in the outcomes than IQ. The only examples in which personality and IQ fared similarly were high-school and college GPA scores. On the other hand, personality was a substantially better predictor than IQ of happiness and life satisfaction. 

We illustrated this graphically with circles. The biggest, white circle represents the whole outcome, and smaller colored circles represent the percentage of that outcome that is explained either by IQ alone (green circle), personality alone (red circle) or IQ and personality together (blue circle - labeled "total"). In all cases, the personality circle is bigger than the IQ circle meaning that it explains a higher percentage of variance in an outcome. In some cases personality circle is almost as big as the blue circle, meaning that IQ adds only a negligible predictive power over personality (i.e., we can predict that outcome almost equally well using only personality compared to using personality and IQ together. Here are our circle plots for each of the outcomes.

What do the other studies say?

Research on personality traits and cognitive abilities as predictors of life outcomes shows mixed results. While some studies suggest personality traits, particularly conscientiousness, are strong predictors of academic achievement, job performance, and life satisfaction (Roberts et al., 2007; Palczyńska & Świst, 2018), others find cognitive abilities to be more influential (Hartmann et al., 2009; Zisman & Ganzach, 2022). Personality traits appear to have incremental validity beyond cognitive abilities in predicting various outcomes (Borghans et al., 2016), however, the relative importance of personality versus cognitive abilities may vary depending on the specific outcome measured and the study design. Overall, both personality traits and cognitive abilities contribute to predicting important life outcomes, with their relative importance differing across various domains and contexts.

Takeaways

• The relative importance of IQ and personality depends on the outcome: some outcomes, such as high-school and college GPA, they predict approximately equally well, while for some outcomes personality is much stronger predictors (happiness and life satisfaction). 

• The effects of IQ and personality tend to be additive, so using both typically makes predictions more accurate than just using one.

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