.50, range, −1.00 −1.00) on a scale where more positive scores indicate greater degrees of right-handedness. Ten of the children in the sample were left-handed (scores below −.40) and seven of these provided sufficient ERP data. Among the final sample of 91 children was 10.6% African American, 6.4% Hispanic, 5.3% Asian, 2.1% Native American, and 75.8% Caucasian. Children were grouped by age into three groups: 10–12 years; 13–14 years; and 15–17 years (see Table 1 for age and sex breakdowns). This research was approved by the Yale University School of Medicine Human Investigation Committee.
