Healthy individuals were recruited by advertisement and compensated for participating. One-hundred eighty participants completed at least one test day. Participants who completed a self-report measure of impulsiveness (n = 105) that was added after the beginning of the parent study comprise the sample for this report. Inclusion criteria were: (i) age 21-30 and (ii) medically and neurologically healthy based on history, physical examination, electrocardiogram, and screening laboratories. Exclusion criteria were: (i) for women: positive pregnancy test or intention to engage in sex without use of birth control; (ii) alcohol naïve; (iii) lifetime DSM-IV diagnosis of any psychiatric disorder including substance use disorders except non-treatment-seeking individuals with alcohol abuse; (iv) any history of counseling or psychotherapy except family therapy focused on relatives; (v) unwillingness to be alcohol free for 48 hours before each test day; (vi) positive urine drug toxicology on test days; (vii) adoptees with no contact with family members; and (viii) a history of maternal alcoholism.
