This study examined attitudes and practices in two risk-taking areas of behavior while under the influence of alcohol--driving and sexuality--within important campus peer subcultures defined by class level and residency associations. Data were drawn from a research project to explore these and other related variables in a major northeastern University. Subjects (N=240), randomly selected from each of seven campus subpopulations (the four undergraduate levels, graduate students, faculty, and staff) were mailed survey questionnaires that assessed: (1) potentially predisposing risk factors, such as demographics, alcohol knowledge, peer usage and pressure, alcohol and drug availability, motivations for drinking, mood, and place of residence; (2) level of respondent's alcohol use; (3) type and frequency of respondent's drug use; and (4) high risk behavior associated with substance use, including driving under the influence and unprotected sexual intercourse. Results, summarized and tabulated, suggest that alcohol and drug use, and associated risk-taking behaviors, vary considerably with both age and social environment, suggesting the influence of campus peer subcultures. Thus it might be productive to concentrate prevention and intervention efforts on identified high-risk peer subcultures, involving peer leaders and peer counseling programs in efforts to modify peer group norms. (Nine references, 5 tables and 12 figures are included.) (TE)