Measurement of impulsivity: Construct coherence, longitudinal stability, and relationship with externalizing problems in middle childhood and adolescence

This study focused on the assessment of impulsivity in nonreferred school-a ged children. Children had been participants since infancy in the Bloomingt on Longitudinal Study. Individual differences in impulsivity were assessed in the laboratory when children were 6 (44 boys, 36 girls) and 8 (50 boys, 39 girls) years of age. Impulsivity constructs derived from these assessmen ts were related to parent and teacher ratings of externalizing problems acr oss the school-age period (ages 7-10) and to parent and self-ratings of the se outcomes across adolescence (ages 14-17). Consistent with prior research , individual measures of impulsivity factor-analyzed into subdimensions ref lecting children's executive control capabilities, delay of gratification, and ability or willingness to sustain attention and compliance during work tasks. Children's performance on the main interactive task index, inhibitor y control, showed a significant level of stability between ages 6 and 8. Du ring the school-age years, children who performed impulsively on the labora tory measures were perceived by mothers and by teachers as more impulsive, inattentive, and overactive than others, affirming the external validity of the impulsivity constructs. Finally, impulsive behavior in the laboratory at ages 6 and 8 predicted maternal and self-ratings of externalizing proble m behavior across adolescence, supporting the longterm predictive value of the laboratory-derived impulsivity measures.