Forty 18-year-old social drinkers will be selected from the sample tested in specific aim 1 ("Prospective Assessment of Adolescent Drinking Trajectories With Computer-Assisted Self-administration of Ethanol (CASE)"; ClinicalTrials.gov identifier: NCT01063166). The functional magnetic resonance imaging blood-oxygen-level-dependent (fMRI BOLD) activity related to disinhibition measured with the Stop Signal task will be assessed during a continuous infusion of alcohol, clamping the arterial Breath Alcohol Concentration (aBAC) at 60 mg% for approximately one hour. It will be examined whether this fMRI BOLD activity is associated with the initial drinking trajectories and the alcohol consumption at age 18 and at age 20 identified in specific aim 1. Furthermore, fMRI will be used with the Taylor Aggression Paradigm to determine which brain areas mediate increased physical aggression during the same continuous infusion of alcohol as described above. All participants will undergo an alcohol and a placebo fMRI session.