Source: Psychology Today, Mar 2017
Intelligence is the most important factor in determining long-term achievement outcomes, and personality is unlikely to compensate for background disadvantage.
Brent Roberts, professor of psychology at the University of Illinois-Urbana Champaign. His work is especially important to consider because he attempts to fully account for the role of intelligence when assessing the impact of other non-cognitive factors.
We found that both cognitive ability and personality traits are important for these outcomes in particular, but that cognitive ability differences have a larger compensatory effect than individual personality traits. … Given the independent effects of cognitive abilities and personality traits, I’d be inclined to argue that both sets of variables are important for education and income but that cognitive abilities are more important than personality traits.
For most achievement-related outcomes like education, cognitive ability is always the strongest predictor. The line that non-cognitive factors do as well or better is just wrong.
My read of the IQ to “soft outcome” literature is that it is vastly overstated.