An additional goal was to provide further evidence for the validity of the DD measure by investigating DD’s association with relevant personality variables and behavioral outcomes such as substance use and other problem behaviors. Consistent with previous studies implicating DD in a broader impulsivity construct, we hypothesized that participants choosing immediate but smaller reward would be characterized by a personality and behavior profile indicating elevated level of eternalizing symptoms. Specifically, we expected that participants making an “impulsive” choice would score higher on the Novelty Seeking (NS) and lower on the Self-Directedness (SD) scales of the Temperament and Character Inventory (TCI) (Cloninger and Svrakic 1997; Constantino et al. 2002), would show more symptoms of conduct disorder and ADHD (particularly its impulsivity component), and would be more likely to report substance use. Finally, we examined possible influence of family socioeconomic status (SES) on the participants’ decision in the reward choice task.
