Loehlin John C, Horn Joseph M, Ernst Jody L
Department of Psychology, University of Texas, Austin, 1 University Station A8000, Austin, TX 78712-0187, USA.
Behav Genet. 2007 May;37(3):463-76. doi: 10.1007/s10519-007-9144-5. Epub 2007 Mar 13.
A short mail questionnaire was sent to individuals, now adults, who had been studied over 30 years ago as children in the Texas Adoption Project. Their parents and (in many cases) siblings also described them using the same questionnaire, and the parents described themselves as well. The questionnaire was designed to obtain information about educational, occupational, and marital outcomes, as well as adult problems and personality. Results were obtained for 324 adopted and 142 biological children from the original 300 families, and for 266 parents. Although both the adopted and biological offsprings' outcomes were generally positive, those for the adopted offspring were somewhat less so. Biologically related family members tended to be more similar in their life outcomes than biologically unrelated family members, suggesting that genes were playing an important role.