Abstract
Adoption studies provide possibilities for estimating the extent to which prenatal environmental events account for individual differences on a trait. Correlations with birth mothers but not adoptive mothers suggest the presence of genetic or prenatal environmental effects; higher correlations with birth mothers than with birth fathers suggest the presence of the latter. Changes over time may also be relevant. The concepts involved are illustrated with parent–child IQ correlations from the Texas and Colorado Adoption Projects.
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Acknowledgments
I am grateful to Robin Corley for providing me with the Colorado IQ data, to Joseph M. Horn, the late Lee Willerman, and the Methodist Mission Home of San Antonio for the Texas data, and to three anonymous referees for helpful comments.
Conflict of Interest
John C. Loehlin have no conflict of interest.
Human and Animal Rights and Informed Consent
No data were gathered directly for this paper. The original studies were reviewed by the relevant institutional ethics committees, and the participants provided informed consent.
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Loehlin, J.C. What Can an Adoption Study Tell Us About the Effect of Prenatal Environment on a Trait?. Behav Genet 46, 329–333 (2016). https://doi.org/10.1007/s10519-015-9730-x
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DOI: https://doi.org/10.1007/s10519-015-9730-x


