Comparisons of adopted and nonadopted adolescents in a large, nationally representative sample

There are conflicting findings about whether adopted children have more psy chological and behavioral problems than nonadoptees. Research results are d iscrepant partly because many previous studies were based on small clinical samples or on samples biased by self-selection. A nationally representativ e school survey (Add Health) was used to compare adopted (n = 1,587) and no nadopted adolescents (total N = 87,165) across a wide variety of measures. Standardized mean differences show that adopted adolescents are at higher r isk in all of the domains examined, including school achievement and proble ms, substance use, psychological well-being, physical health, fighting, and lying to parents. Demographic and background variable breakdowns show that the effect sizes for differences between adopted and nonadopted adolescent s were larger for males, younger or older adolescents, Hispanics or Asians, and adolescents living in group homes or with parents of low education. Di stributional analyses revealed approximately a 1:1 ratio of adopted to nona dopted adolescents in the middle ranges of the outcome variables but a rati o of 3:1 or greater near the tails of the distributions. These data clearly show that more adopted adolescents have problems of various kinds than the ir nonadopted peers; effect sizes were small to moderate based on mean diff erences, but comparisons of distributions suggest much larger proportions o f adopted than nonadopted adolescents at the extremes of salient outcome va riables.