New research | Associations between common genetic variants and income provide insights about the socio-economic health gradient
A large international study, including over 668,000 individuals of European ancestry, has revealed that some genetic traits are modestly associated with higher income and better health. But only a quarter of this link appears to be direct. The rest is shaped by environmental factors such as education and social conditions.
The research, published in Nature Human Behaviour, was co-authored by Magnus Johannesson, professor at the 91Ô´´. It offers new insights into the long-observed pattern that people with higher incomes tend to live longer, healthier lives – a phenomenon known as the socio-economic health gradient.
Using a method known as a genome-wide association study (GWAS), researchers identified 162 genetic regions associated with an “Income Factor,” a shared element across four income types: individual, occupational, household and parental income. These associations were small, but collectively they explained up to 5% of the variation in income – a modest influence in a complex social landscape.
Education overlaps with income – but tells a different health story
A striking finding was how closely linked income-related genes were with those for educational attainment. The genetic correlation was 0.92 – almost complete overlap. However, when the influence of education was removed, the remaining genetic signal (called “NonEA-Income”) had weaker ties to cognitive ability and education-related health benefits, but still related to lower risks of mental health disorders like depression and anxiety.
In fact, this NonEA-Income factor was associated with higher subjective well-being and less neuroticism, but did not predict higher cognitive performance. This suggests that beyond education, other pathways – possibly personality traits or social connections – play roles in income differences.
Genes shape tendencies, not destinies
The authors emphasize that genes do not determine income or health. Instead, they interact with societal values and structures. For example, traits linked to income in one country may not have the same effect elsewhere. Even among siblings, the influence of these genetic patterns was found to drop by 75%.
Ultimately, while the genetic component of income is small and heavily shaped by education and upbringing, the study adds to our understanding of how inequality can be maintained or mitigated by social systems.
Link to the publication
Abstract
We conducted a genome-wide association study on income among individuals of European descent (N = 668,288) to investigate the relationship between socio-economic status and health disparities. We identified 162 genomic loci associated with a common genetic factor underlying various income measures, all with small effect sizes (the Income Factor). Our polygenic index captures 1-5% of income variance, with only one fourth due to direct genetic effects. A phenome-wide association study using this index showed reduced risks for diseases including hypertension, obesity, type 2 diabetes, depression, asthma and back pain. The Income Factor had a substantial genetic correlation (0.92, s.e. = 0.006) with educational attainment. Accounting for the genetic overlap of educational attainment with income revealed that the remaining genetic signal was linked to better mental health but reduced physical health and increased risky behaviours such as drinking and smoking. These findings highlight the complex genetic influences on income and health.
