In youth, maladaptive personality traits such as urgency (the tendency to act rashly when highly emotional) predict early onset alcohol consumption. In adults, maladaptive behaviors, including substance use, predict negative personality change. This article reports on a test of hypothesized maladaptive, reciprocal prediction between youth drinking and the trait of urgency. In a sample of 1,906 youth assessed every 6 months from the spring of 5th grade through the spring of 8th grade, and again in the spring of 9th grade, the authors found such reciprocal prediction. Over each 6 month and then 12 month time lag, urgency predicted increased subsequent drinking. In addition, over 6 of the 7 time lags, drinking behavior predicted subsequent increases in urgency. During early adolescence, maladaptive personality and dysfunctional behavior each led to increases in the other. The results of this process include cyclically increasing risk for youth drinking and may include increasing risk for the multiple maladaptive behaviors predicted by the trait of urgency. (PsycINFO Database Record