A genetic common factor underlying self-reported math ability and highest math class taken

While genetic influences on general intelligence have been well documented, less is known about the genetics underlying narrower abilities ("group factors"). By applying structural equation modeling to results from several genome-wide association studies (GWAS), most critically of self-reported math ability (N = 564 698) and highest math class taken (N = 430 445), we identified 53 single-nucleotide polymorphisms (SNPs) associated with a latent trait, orthogonal by design with general intelligence, approximating the group factor of quantitative ability. The genes near these SNPs implicated the biological process of neuron projection development, and the genome-wide pattern of gene-set enrichment affirmed the involvement of brain development and synaptic function. We calculated a number of genetic correlations with this quantitative factor, finding negative associations with both internalizing and externalizing disorders and positive associations with STEM occupations such as computer programming. These results provide further evidence for genetic influences on traits other than general factors in human behavioral variation, point to the mechanisms mediating these genetic influences on quantitative ability and interests, and affirm the relationships of the latter traits with a number of real-world outcomes.