Functional and Dysfunctional Forms of Impulsivity:

"Dickman (1990) proposed the existence of both “functional” and “dysfunctional” forms of impulsivity, suggesting that impulsivity may be beneficial in some circumstances. The scale he devised to measure functional impulsivity assesses comfort with acting, talking, and making decisions quickly, with little or no deliberation, when the situation calls for it, such as in fast-paced conversation or sport, or in the presence of fleeting opportunity. Block (2002) has similarly argued that some degree of “undercontrol” is not detrimental because it allows spontaneous exploration and utilization of unforeseen opportunities. Although impulsivity has typically been considered only as a dysfunctional tendency, the possibility of an adaptive form or level of impulsivity is worth keeping in mind when examining the association of impulsivity with other personality traits."

Personality and Self-Regulation, Colin DeYoung