Genetic and environmental influences on vocabulary IQ: Parental education level as moderator

Citation

Rowe, D. C.; Jacobson, K. C.; & Van den Oord, E. J. C. G. (1999). Genetic and environmental influences on vocabulary IQ: Parental education level as moderator. Child Development. vol. 70 (5) pp. 1151-1162

Abstract

This article examines how parental education level moderates the genetic and environmental contributions to variation in verbal IQ. Data are from 1909 non-Hispanic Whites and African American sibling pairs from the National Longitudinal Study of Adolescent Health, which obtained nationally-based samples of identical (MZ) twins, fraternal (DZ) twins, full and half siblings, cousins (in the same household), and biologically unrelated siblings. In the whole sample, the variance estimate for heritability (h2 = .57, SE = .08) was greater than that for shared environment (c2 =.13, SE = .04). Both heritability and the shared environmental estimate were moderated, however, by level of parental education. Specifically, among more highly educated families, the average h2 = .74 (SE = .10) and the average c2 = .00 (SE = .05). Conversely, among less well-educated families, heritability decreased and shared environmental influences increased, yielding similar proportions of variance explained by genetic and environmental factors, average h2 = .26 (SE = .15), and average c2 = .23 (SE = .07).

URL

http://dx.doi.org/10.1111/1467-8624.00084

Keyword(s)

Genetics

Reference Type

Journal Article

Journal Title

Child Development

Author(s)

Rowe, D. C.
Jacobson, K. C.
Van den Oord, E. J. C. G.

Year Published

1999

Volume Number

70

Issue Number

5

Pages

1151-1162

DOI

10.1111/1467-8624.00084

Reference ID

20