Building on the findings from this article and consistent with the recent suggestions (e.g., Roberts and Mroczek, 2008) regarding the study of personality change, the next important step will be to determine why individuals exhibit individual differences in impulsivity. Changes in personality have been previously linked to several life and work experiences, including relationship and work satisfaction (e.g., Scollon and Diener, 2006). Thus, future work utilizing the impulsivity trajectories presented in this article could examine the link between marital and parental status as well occupational attainment with impulsivity trajectory groups. Additionally, a number of other potentially important time-invariant covariates of developmental changes in impulsivity could be considered, including sex, family history of alcoholism, childhood life events, and age of onset of heavy alcohol use. Finally, a number of time-varying covariates, including variables relevant to alcohol involvement, could also be considered, such as drinking motives, reasons for not drinking, and drinking expectancies.
