Genetic factors drive the link between cognitive ability and socioeconomic status
by
Eric W. Dolan
March 10, 2026
in
Cognitive Science,
Evolutionary Psychology
A new study published in
Scientific Reports suggests that the connection between a young adult’s cognitive ability and their future socioeconomic status is largely driven by their genes. The findings provide evidence that genetic factors play a larger role in educational and occupational success than environmental conditions. This underlying biology may help explain why some social interventions aimed at reducing inequality tend to fall short over the long term.
Social scientists have spent decades trying to understand the psychological mechanisms that drive socioeconomic status. Getting an education and securing a job are the primary ways young adults begin earning a living and establishing their place in society. Past research reliably shows that general cognitive ability, often measured as an intelligence quotient, is the strongest predictor of a person’s future socioeconomic position.
However, it has remained unclear whether this relationship is primarily driven by a person’s unique genetics or by their personal life experiences. Such experiences might include the social networks a person builds in college or the specific opportunities they encounter in the job market.
Petri J. Kajonius, an associate professor and personality researcher at the Department of Psychology at Lund University in Sweden and host of
Personlighetspodden, conducted this study to answer that question.
“Most people, even psychology researchers, are not aware that most correlations in psychological science are mostly driven by genetics, and not the environment. This unawareness may be particularly true in Sweden — famous for its focus on societal equality through interventions — and not many studies in social sciences attempt to control for individual genetics. This is arguably one of the first genetically informed studies from Sweden testing the well-known and very strong IQ-socioeconomic status relationship.”
In particular, Kajonius wanted to quantify exactly how much of the link between a young adult’s cognitive ability and their later socioeconomic status can be attributed to genetic inheritance. To examine this, the researcher utilized data from the TwinLife project, a large and representative study of families in Germany. The sample included 440 twin pairs, consisting of 228 identical twin pairs and 212 fraternal same-sex twin pairs.
Analyzing twins allows scientists to estimate how much of a particular trait is due to genetics. Identical twins share all of their genes, while fraternal twins share about half of their genes on average. By comparing the similarities between these two types of twins, researchers can mathematically calculate how much of a trait is due to genetic inheritance versus environmental exposure.
The participants in this specific analysis were young adults transitioning into their careers. They had an average age of about 23 during the first wave of data collection and an average age of about 27 during the second wave four years later. During the first wave of the study, the participants completed a computer-based cognitive assessment.
This assessment measured a person’s ability to reason and solve problems using unfamiliar information, which is a core component of general intelligence. Four years later, the researchers measured the participants’ socioeconomic status using four distinct variables. Two of these variables focused on educational attainment, classifying the complexity and level of schooling each participant had completed on a scale from zero to ten.
“The take-home message for the average person is that psychology manifests in life mostly through genetic make-up, not so much through environmental conditions,” Kajonius told PsyPost. “The individual is arguably more important than given credit when it comes to life outcomes, such as education, occupation, and income. This may consequently also be one reason societal interventions aimed at equality often don’t work in the long-term.”
A new study of German twins suggests that the strong connection between a young adult's cognitive ability and their future socioeconomic status is largely driven by their genes, rather than shared family environments or random life events.
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