Dimensions of impulsive behavior: Personality and behavioral measures

Impulsivity as a behavioral construct encompasses a wide range of what are often considered maladaptive behaviors. Impulsivity has been assessed using a variety of measures, including both self-report personality questionnaires and behavioral tasks, and each of these measures has been further subdivided into separate components which are thought to represent different underlying processes. However, few studies have employed both personality measures and behavioral tasks, and so the relations among these measures are not well understood. In one analysis we examined correlations between three widely used personality measures (i.e., BIS-11, I₇, and MPQ) and four laboratory-task measures of impulsive behavior (behavioral inhibition (2), delay discounting, and risk taking) in 70 healthy adult volunteers. The correlations among the various self-report measures were high, but self-reports were not correlated with behavioral-task measures. In a second analysis we performed a principal-components analysis using data from the four behavioral tasks for 99 participants. Two components emerged, labeled "impulsive disinhibition" (Stop Task and Go/ No-Go task) and "impulsive decision-making" (Delay-Discounting task and Balloon Analog Risk Task). Taken collectively, these analyses support other recent findings indicating that self-report and behavioral tasks probably measure different constructs, and suggest that even among the behavioral measures, different tasks measure different, perhaps unrelated, components of impulsive behavior.