- Intelligence is a highly heritable trait, with heritability increasing from about 20% in infancy to as much as 80% in later adulthood.
- Intelligence captures genetic effects common to diverse cognitive and learning abilities, with genetic correlations around 0.60 or higher.
- Assortative mating for intelligence is high (spouse correlations ~0.40), which increases additive genetic variance in the population.
- The genetics of high intelligence are continuous with normal variation; high intelligence is just as heritable as the rest of the distribution.
- Intelligence shares genetic causes with education and social class, linking genetics to social mobility and health outcomes.