to each item by using a 5-point scale to rate how true each statement was for the adolescent. For the teacher-reported effortful control scale, teachers responded to five items related to effortful control by rating the frequency of each participant’s behaviors on a 5-point scale (e.g., “thinks ahead of time about the consequences of actions;” “pays attention to what he or she is doing,”). The adolescent-report scale had inter-subscale correlations ranging from 0.22 to 0.45, a mean inter-item correlation of 0.14, and a standardized item alpha of 0.63. When multiple parent respondents were available, those responses were averaged into one parent-reported scale. The parent-report scale had inter-subscale correlations from 0.39 to 0.66, a mean inter-item correlation of 0.22, and a standardized item alpha of 0.79. The teacher-report scale had a mean inter-item correlation of 0.76 and a standardized item alpha of 0.94.
