Biomaterial Database

Genetic and environmental influences on adult intelligence and special mental abilities. 1998

T J Bouchard

Department of Psychology, University of Minnesota, Minneapolis 55455-0344, USA.

I review representative biometric studies of adult twins and adoptees that have been used to generate estimates of genetic and environmental influence on intelligence (IQ) and special mental abilities. The various studies converge on a heritability estimate between 0.60 and 0.80 for IQ. Estimates of common environmental influence from the same studies are near zero. Studies of twins reared together and studies of unrelated individuals reared together yield sizable estimates of common family environmental influence in childhood but also demonstrate that this influence dissipates with age and approaches zero in adulthood. Twin studies of the major special mental abilities (verbal, spatial, perceptual speed and accuracy, memory) yield heritability estimates of about 0.50 and modest estimates of common environmental influence.

UI	MeSH Term	Description	Entries
D007360	Intelligence	The ability to learn and to deal with new situations and to deal effectively with tasks involving abstractions.
D008606	Mental Processes	Conceptual functions or thinking in all its forms.	Information Processing, Human,Human Information Processing
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D000328	Adult	A person having attained full growth or maturity. Adults are of 19 through 44 years of age. For a person between 19 and 24 years of age, YOUNG ADULT is available.	Adults
D018433	Twin Studies as Topic	Works about methods of detecting genetic etiology in human traits. The basic premise of twin studies is that monozygotic twins carry identical genes, while zygotic twins are genetically no more similar than two siblings born after separate pregnancies. (Last, J.M., A Dictionary of Epidemiology, 2d ed)