Aim: To evaluate cognitive and neuropsychological abilities of adopted delinquent adolescents in institutional care. Methods: Transnationally adopted adolescents admitted to institutional care (n= 20) and non-delinquent controls who were also transnationally adopted (n= 21) were compared concerning the Wechsler Intelligence Scale for Children and Adults (WISC and WAIS), the Wisconsin Card Sorting Test (WCST) and the Tower of London test (TOL). The adoptive parents answered questions about the adoption, early childhood and family circumstances by a questionnaire sent by mail. Results: The adopted delinquents had a significantly lower IQ and significantly lower results on several other measurements in the WISC/WAIS compared to the controls even after adjustment for age of arrival in the adoptive home. Both groups of adoptees scored low in the WISC/WAIS subscale of arithmetics when compared to the population mean. The TOL test showed that the delinquents were slower and made more errors than the controls.
Conclusion: The delinquent adoptees scored significantly lower on many variables in the WISC/WAIS. Both delinquent and non-delinquent adoptees had some difficulties with arithmetic. The weak performances in arithmetics might point to some weaknesses in the neuropsychological domain. These results probably have complex explanatory causes and need to be further evaluated.