This application requests four years of support to investigate the biobehavioral mechanisms mediating risk for alcohol abuse in human and non-human animal subjects. The first aim of the project is to investigate the biobehavioral mechanisms hypothesized to mediate the relationship between disinhibited behavior and alcohol abuse. The central hypotheses are that a common vulnerability mediates the relationship between impulsive personality, disinhibited/antisocial behavior and alcohol abuse. The relationship between alcohol problems, disinhibited behavior, and individual differences in the strength of the Behavioral Inhibition and Activation Systems (i.e. the biobehavioral mechanisms), assessed using classical and instrumental conditioning of psychophysiological and motor responses, measures of autonomic arousal while awaiting an aversive event, and fear-potentiated startle will be examined using latent variable and structural-equation techniques in a sample of young men and women. The second aim is to investigate behavioral inhibition and activation functioning in replicated strains of rats bred for alcohol preference, alcohol preferring (P) rat and the high-alcohol drinking (HAD) rat, using conditioning protocols that parallel the human protocols, and to compare a human model of alcoholism-risk (persons with undercontrolled, disinhibited or aggressive behavior) with the animal model (the P and HAD rat) to determine how well the animal model generalizes to the human model in terms of behavioral inhibition and activation. In addition the predictive power of behavioral inhibition and activation function on alcohol consumption will be examined in a F-2 generation of cross bred P rats and alcohol non-preferring (NP) rats and HAD and low-alcohol drinking (LAD) rats. The results of this project should yield data relevant to the prevention of alcohol abuse, especially in high-risk youth. In addition, the results may inform treatment efforts with populations where antisocial personality is co-morbid with alcohol dependence.