In a two-decade study of children adopted into Caucasian families completed in 1999, Brooks and Barth found that compared to transracially adopted children, Caucasian male adoptees reported the most problematic adjustment [6]. They reported that more important than placement type (transracial or inracial) is gender and family structure. Contrary to previous studies, they also concluded that age of adoption and previous temporary placement in foster care or orphanages was not particularly detrimental to children’s well-being.

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A study performed at the University of Minnesota from 1998-2004 tackled more common misconceptions by studying quantitative indicators of mental health and prevalence of childhood disorders in non-adoptees, internationally placed and domestically placed adoptees [14]. They did find that “the adoption effect” did exist – overall, adoptees had a significantly greater number of externalizing problems than non-adoptees as reported by teacher, parent, and child. What was interesting is that when they compared domestic and international adoptees, they disproved the typical assumption that international adoptees are more likely to have worse mental health scores due to placement at a late age or preplacement adversity. Rather, they discovered that domestic adoptees had higher prevalence of externalizing disorders; they hypothesized that this may because 1) adoptive parents of international adoptees are better equipped to raise an adopted child than those of domestic adoptees and 2) domestic adoptees may be more likely to experience prenatal exposure to teratogenic substances or carry a greater risk for mental health problems than international adoptees [14]. This study was limited by the records involved – results were gathered only from Minnesota birth records and were therefore non-reflective of U.S. ethnic diversity or the locations from which children are adopted from at the time.