Family Genetics Tie Emotional Stability to Economic Outcomes

Personality has long been correlated with labor-market success and wealth, but those correlations are difficult to interpret: upbringing, parental resources, education, and inherited traits all move together. Carvalho and colleagues use variation in the genetic material parents randomly transmit to their children to narrow that problem. Their central result is selective rather than broad: genetic propensity toward emotional stability is associated with higher earnings and household wealth, while propensity toward conscientiousness is associated with higher wealth; the remaining Big Five dimensions do not show a consistent pattern.

Core Contribution

The paper treats differences in siblings' inherited polygenic indexes (PGIs) as a source of quasi-random variation, conditional on the combined PGIs of their parents. That conditioning is the key design choice. It aims to compare people who come from the same genetic and family background in aggregate but received different genetic draws at conception, rather than comparing unrelated people whose family circumstances may differ in many ways.

The authors first test an implication of that design. Before parental PGIs are included, an individual's personality PGIs are associated with family-background measures such as parental net wealth and number of siblings. Once the corresponding parental PGI sums are controlled for, those associations largely disappear. Figure 1 presents this as both coefficient comparisons and absolute t-statistics across a wider set of background measures. It is not a proof that every family-level channel is removed, but it is direct evidence that the parental conditioning changes the empirical comparison in the intended direction.

Technical Approach

The analysis combines Lifelines cohort genotypes and personality surveys with 19 years of Dutch administrative tax records. The estimating specification includes the five standardized Big Five PGIs jointly and conditions on the sums of the parents' corresponding PGIs. Joint estimation matters because the genetic predictors are correlated; the coefficient for one PGI is interpreted while holding the other four genetic propensities fixed.

The paper then checks whether the inherited PGI differences map onto measured personality. Figure 2 reports the within-family estimates for conscientiousness, extraversion, and emotional stability in 37,768 people. Both the indexes and survey traits are standardized, so coefficients are expressed in standard-deviation units. This validation step distinguishes the study from an exercise that would use genetic scores only as labels: the authors test whether the transmitted variation moves the personality measures it is meant to proxy.

For economic outcomes, the authors estimate effects on annual earnings and household net wealth in both currency levels and percentile ranks. The earnings analysis uses 574,690 person-year observations from 38,936 individuals; the wealth analysis uses 566,810 person-year observations from 38,934 individuals. Using ranks alongside levels reduces dependence on a single way of representing the skewed outcome distributions.

Results and Analysis

Emotional-stability PGI variation is positively associated with annual earnings and household wealth. Conscientiousness PGI variation is positively associated with household wealth, but not presented as a similarly consistent earnings result. Openness, extraversion, and agreeableness do not show a stable pattern across outcomes and specifications. That asymmetry is the paper's most useful corrective to a generic claim that personality broadly drives economic attainment: the evidence is concentrated in two dimensions and strongest for emotional stability.

Figure 3 lays out the earnings and wealth estimates in levels and percentile ranks, with 95% confidence intervals. The result persists when outcomes are represented in either form, which supports the reported direction of the emotional-stability association rather than an artifact of only one outcome scale. The authors also progressively account for genetic propensity toward educational attainment, cognitive performance, and depression; the emotional-stability association with earnings remains positive after those adjustments. That pattern makes a simple interpretation through those measured genetic pathways less persuasive, although it does not identify a single behavioral mechanism.

Limits on the Causal Reading

The design improves on conventional observational personality research, but it estimates effects of PGIs, not interventions that directly change a trait. PGIs capture only part of genetic propensity and may carry discovery-sample and measurement limitations. Conditioning on parental scores addresses parental genetic composition, yet it cannot by itself rule out every sibling interaction or environmental response to a child's genetically influenced behavior. Finally, the evidence comes from a Dutch cohort with available parental genotypes and linked records, so its size and administrative follow-up do not establish that the estimated relationships transfer unchanged to other populations or institutions.