A study of adopted children, their environment, and development:

The study explores the developmental consequences for children who have been adopted. The comparison group is comprised of their non- adopted siblings or children in foster homes or group care. A search in scientific databases resulted in more than 3,300 hits about adoption. Among these, 56 fulfilled the selection criteria from 17 studies across more than 2,000 adoptees and controls. Adopted children scored higher on IQ, school-performance, and lack of behavioral problems than their non-adopted siblings or peers who stayed behind in orphanages or foster homes. The results from OECD countries were similar to those from studies in Chile, Lebanon, and India.