The literature both supports and challenges the notion that adult children of alcoholics are a distinct and homogenous group. College students (n = 200) were placed into one of four categories: Adult Children of Alcoholics, Adverse Childhood Event Group, Alcohol and Adverse Childhood Event Group, and the No Adverse Event Group. Participating college students then completed instruments that measured drug and alcohol use, adult children of alcoholics traits, defensiveness, impulsivity, and resistance to change. Differences surfaced on two instruments, the Drug Abuse Screening Inventory and the Children of Alcoholics Scale. Adult children of alcoholics were overrepresented as CAST+ and underrepresented as CAST-. The Alcohol and Adverse Event groups were underrepresented in the DAST+ category. (Contains 1 table.)