Social scientist
Barry Mehler defines hereditarianism as "the belief that a substantial part of both group and individual differences in human behavioral traits are caused by genetic differences". Hereditarianism is sometimes used as a
synonym for
biological or
genetic determinism, though some scholars distinguish the two terms. When distinguished, biological determinism is used to mean that heredity is the only factor. Supporters of hereditarianism reject this sense of biological determinism for most cases. However, in some cases genetic determinism is true; for example,
Matt Ridley describes
Huntington's disease as "pure fatalism, undiluted by environmental variability". In other cases, hereditarians would see no role for genes; for example, the condition of "
not knowing a word of Chinese" has nothing to do (directly) with genes. Hereditarians point to the heritability of cognitive ability, and the outsized influence that cognitive ability has on life outcomes, as evidence in favor of the hereditarian viewpoint. According to Plomin and Van Stumm (2018), "Intelligence is highly heritable and predicts important educational, occupational and health outcomes better than any other trait." Estimates for the
heritability of intelligence range from 20% in infancy to 80% in adulthood. == History ==