Alcohol expectancy has proven to be a powerful predictor of drinking behavior, including alcoholism, in a wide range of groups. Three recent studies that begin to address expectancy's relation to other alcoholism vulnerability factors are reviewed. Results indicate that: (1) expectancies for reinforcement from alcohol predate teens' first drinking experiences; (2) expectancies predict subsequent drinking onset and problem drinking; (3) high initial expectancies lead to a vicious cycle of progressively more drinking and more positive expectancies during the adolescent years; (4) expectancy mediates the influence of family drinking history on adolescent drinking; and (5) as an alcohol-specific risk factor, expectancy adds to and (in women) interacts with more general, dispositional (personality) risk factors to predict problem drinking in young adults. These findings support the model of expectancy as a mediator of the original causal influences of earlier learning experiences.