“Genetic ‘General Intelligence’, Objectively Determined and Measured”, 2019-09-12 (; backlinks; similar):
It has been known for 115 years that, in humans, diverse cognitive traits are positively intercorrelated; this forms the basis for the general factor of intelligence (g).
We directly test for a genetic basis for g using data from 7 different cognitive tests (n = 11,263 to n = 331,679) and genome-wide autosomal single-nucleotide polymorphisms. A genetic g factor accounts for 58.4% (SE = 4.8%) of the genetic variance in the cognitive traits, with trait-specific genetic factors accounting for the remaining 41.6%.
We distill genetic loci broadly relevant for many cognitive traits (g) from loci associated with only individual cognitive traits.
These results elucidate the etiological basis for a long-known yet poorly-understood phenomenon, revealing a fundamental dimension of genetic sharing across diverse cognitive traits.