- Race plays a part. This study was done with Korean Infants adopted around 30 years ago when race played a much greater role in success
- Age at adoption plays a part. If there’s one thing that gets hammered into American parents it’s that nutrition during the infant years has an impact on a child’s life. If someone is, for example, malnourished during their infant years there can be severe physical and neurological consequences.
- Genetics certainly play a part. Let’s be realistic here, Intelligence is at least part genetic. I got As in High School without even trying while friends with more affluent parents struggled. Is there really anyone who doesn’t believe intelligence is at least partially genetic?
There are probably tons more if I spent some time thinking on it. Bottom line: The study proves nothing. Moreover I suspect the question of whether adopted kids can be as successful as biological ones is far too vast to really have a definitive answer.