Citation

Duyme M, Dumaret AC, Tomkiewicz S. Proc. Natl. Acad. Sci. U. S. A. 1999; 96(15): 8790-8794.

Affiliation

Institut National de la Santé et de la Recherche Médicale U.155, Epidémiologie Génétique, Université Paris VII, 75251 Paris, France. duyme@ccr.jussieu.fr

Copyright

(Copyright © 1999, National Academy of Sciences)

DOI

unavailable

PMID

10411954

PMCID

PMC17595

Abstract

From 5,003 files of adopted children, 65 deprived children, defined as abused and/or neglected during infancy, were strictly selected with particular reference to two criteria: (i) They were adopted between 4 and 6 years of age, and (ii) they had an IQ <86 (mean = 77, SD = 6.3) before adoption. The average IQs of adopted children in lower and higher socioeconomic status (SES) families were 85 (SD = 17) and 98 (SD = 14.6), respectively, at adolescence (mean age = 13.5 years). The results show (i) a significant gain in IQ dependent on the SES of the adoptive families (mean = 7.7 and mean = 19.5 IQ points in low and high SES, respectively), (ii) IQs after adoption are significantly correlated with IQs before adoption, and (iii) during adolescence, verbal IQs are significantly lower than performance IQs.

Language: en