Notably, the trajectory group characterized by developmentally limited levels of relatively high impulsivity tended to exhibit accelerated declines in alcohol use and outcomes compared to other classes characterized by high and relatively stable levels of impulsivity across time, although these differences in alcohol involvement tended to become nonsignificant at later time points. This pattern of covariation between impulsivity trajectory groups and alcohol involvement may be best labeled as developmental lag markers (see Sher et al., 2004). That is, it appears that individuals who exhibit relatively high and stable levels of impulsivity also show delayed normative decreases in alcohol involvement compared to classes that are characterized by relatively low levels of impulsivity by age 25 (see Fig. 2).
