Largest genetic study of cognition links 550 common variants and 26 genes to test scores

Researchers at the Wellcome Sanger Institute, Amsterdam University Medical Center and collaborators published what they call the largest genetic study of cognition to date in Nature Genetics on 5 October 2026.

The method

UK Biobank participants were asked to complete a problem-solving test (verbal-numerical reasoning), but about 40% never did, and those who did were more likely to have higher education — a distortion called ascertainment bias. The team used other information about the non-takers (health, behaviour, socioeconomic measures) to statistically estimate their likely scores, increasing the sample from about 270,000 to more than 455,000 people of European ancestry.

Findings

• The number of common DNA variants associated with test scores rose from 390 to 550 (a 40% increase); each has a very small effect.
• Genes in which rare variants are linked to scores rose from 5 to 26, all associated with lower scores. 14 were already known to cause neurodevelopmental conditions; 4 had earlier links to test scores or education in UK Biobank; 8 had no strong previous evidence, though they showed more variants in patients with neurodevelopmental conditions.
• Most UK Biobank carriers of these rare variants have no neurodevelopmental diagnosis, suggesting effects on cognition below a clinical threshold.

Limitations

The estimated scores are not the same as measured intelligence, and the researchers say better direct measurement remains the most robust approach; they tested that the estimates were not just echoing the data used to compute them. The study included only people of European ancestry, and the authors stress the results are for understanding cognition at a group level, not for predicting any individual’s ability. Cognitive ability is shaped by both genes and environment.