COGNITIVE-ABILITIES OF CHILDREN AT 7 AND 12 YEARS OF AGE IN THE COLORADO-ADOPTION-PROJECT

To test the hypothesis that adopted children are at an elevated risk f or learning disabilities, the achievement and WISC-R test scores of a nonclinical sample of adopted and nonadopted (control) children were c ompared at 7 years of age (n = 108 adopted males, 91 adopted females, 116 control males, 100 control females) and 12 years of age (n=69 adop ted males, 61 adopted females, 56 control males, 44 control females). Although the average Verbal IQ of the adopted children was significant ly lower than that of the nonadopted children at both ages, these diff erences accounted for only about 2% to 4% of the variance. When scores on the individual subtests of the WISC-R were compared, the group dif ference was significant only for Similarities at age 7, and for Compre hension at age 12. Moreover, with regard to the achievement tests, the proportion of adopted children who scored more than 1.5 standard devi ations below expected, based on IQ, was not significantly greater than that of controls. Also, the proportions of adopted and control childr en placed in special education classes were not significantly differen t. Thus, the results of this study provide little or no evidence for a n increased risk of learning disabilities in ''easily placed'' adopted children.