We like to strive for the idea that everyone gets equal opportunities. Especially in countries with extensive social safety nets and accessible education systems, like Sweden, we expect that origin or background will increasingly determine how far you get in education. However, recent research shows that something else is at play that has a surprisingly large influence: our genes.

Swedish researcher Oskar Pettersson investigated how strongly genetic predisposition influences educational attainment, particularly how that influence changed during the 20th century. To do this, he used data from Swedish twins born between 1920 and 1999, combined with polygenetic scores that predict an individual’s educational attainment based on DNA.

The results are remarkable but not illogical. As Sweden became more prosperous and equal and access to education improved, the influence of genes on educational attainment increased. In other words, genetic predisposition became more important in determining how much education someone received as society became more equal. Especially before the major educational reforms of the 1960s, children from highly educated families had a genetic advantage, probably because their environment gave them extra incentive to use that predisposition.

But the story doesn’t stop there. From the 1960s onwards, when education became more accessible, this picture changed radically. Genetic influence differences between children of higher and lower-educated parents largely disappeared. Genes started to play a greater role in children from lower-educated families, while in families with highly educated parents, this influence actually decreased somewhat.

Pettersson suggests that Swedish education and a more equal society have led to a ‘raising of the lower limit’. Where children with fewer opportunities were previously less able to use their genetic potential, this has become increasingly possible due to improved circumstances.

There is a catch, however. Although genes increasingly predicted how much education someone had, researchers did not see a similar increase in their influence on income. A high education level does not automatically guarantee a higher income.

Abstract of the study :

Interest in the role of genetics in influencing key life outcomes such as educational attainment has grown quickly. However, the question of whether genetic influences on educational attainment, on average as well as in conjunction with socioeconomic circumstances, are moderated by macro-level factors has not yet received sufficient attention. This study combines polygenic indices for educational attainment (EA PGI) with high-quality register data in a large sample of Swedish twins of European ancestry born 1920–1999. Employing both conventional between-family and within-family models, the analyzes suggest that the influences of education-related genetic propensities on educational attainment have increased in Sweden during the twentieth century, a period featuring major expansions of the Swedish educational system, and decreasing economic inequality. The analyzes also suggest that the degree to which socioeconomic background enhances genetic influences on education has decreased across cohorts. Genetic influences on education do not appear to have translated into increased genetic influences on income. Additionally, there is some evidence of floor and ceiling effects in the analyzes of dichotomous educational outcomes.