We examine the effects of cognitive and non‐cognitive individual differences on the dynamics of career success (i.e. pay, occupational status) by comparing temporal changes in the validities of two measures of personality—Core Self Evaluations and the Big Five personality dimensions—to temporal changes in the validities of two standard intelligence tests. The main finding of two studies based on large representative samples is that the validity of intelligence clearly increases over time, whereas the validity of personality tends to be stable, indicating that intelligence, but not personality, drives career success.