Determine the extent of pleiotropic bias in personality PGI estimates

Determine whether genetic propensity toward the Big Five personality traits affects earnings and household wealth through alternative genetic pathways that are not captured by polygenic-index controls for educational attainment, cognitive performance, and major depressive disorder.

Background

The study estimates within-family effects of polygenic indexes (PGIs) for the Big Five personality traits on earnings and household wealth. To assess whether these effects operate specifically through personality, the analysis controls for PGIs associated with educational attainment, cognitive performance, and major depressive disorder. These controls attenuate some estimates but do not establish that all relevant alternative genetic pathways have been removed.

The unresolved issue is whether unmeasured or insufficiently captured pleiotropic pathways continue to contribute to the estimated effects. The problem is complicated because controlling for downstream pathways may also remove part of the genuine total effect of personality—for example, an effect mediated through education—so adjusted estimates may understate the total causal effect.

References

An important limitation is that our approach cannot rule out pleiotropy altogether.

— Random Genetic Variation Links Personality to Earnings and Wealth  (2610.06088 - Carvalho et al., 5 Oct 2026) in Discussion, paragraph beginning “An important limitation is that our approach cannot rule out pleiotropy altogether.”