Adoptee overrepresentation among clinic-referred boys with gender identitydisorder

Objectives: To test the hypothesis that adoptees are overrepresented among a sample of clinic-referred boys with gender identify problems (N = 238). T o compare the adoptees and nonadoptees on demographic, behaviour problem, a nd gender-typed measures. Method: The percentage of clinic-referred boys with gender identity problem s adopted in the first 2 years of life ("early adoptees") was compared to t he base rate of boys adopted in Ontario. Parent-report and behavioural meas ures were used to compare the early adoptees with "late adoptees" (adopted after the second year of life) and nonadoptees. Results: The percentage of boys with gender identity problems who were earl y adoptees (7.6%) was significantly higher than the base rate of males adop ted in Ontario in the first 2 years of life (1.5%). Both the early and late adoptees were significantly less intelligent than the nonadoptees. The ear ly adoptees also had significantly higher externalizing T scores on the Chi ld Behavior Checklist than did the late adoptees and the nonadoptees. The 3 groups did not differ in the percentage who met the complete Diagnostic an d Statistical Manual of Mental Disorders (DSM) criteria for gender identity disorder and on 4 other measures of gender-typed behaviour. Conclusion: Adoptees are overrepresented among clinic-referred boys with ge nder identity problems. The reasons for this finding are not clear bur may be accounted for by general risk factors that increase the likelihood of cl inical referral or by psychosocial and biological factors associated with a doption.