Richard J. Rose1, J. Kapio2,3, L. Pulkkinen4, R .J. Viken1, M. Koskenvuo5
Genetic and environmental influences on behavioral precursors of alcoholism are studied in two ongoing, longitudinal studies of Finnish twins and their parents. FinnTwin16 has baseline data on 2,810 16 year-old twin pairs; questionnaire baseline assessments of FinnTwin12, in progress, are complete for >2,000 twins, and school-based assessments, including peer-nominations for eight dimensions of social behavior, are available for 413 pairs of known zygosity. Abstinence rates at age 16 are influenced by socio-regional variation, sibling interaction effects, and parental drinking patterns, with influences of both sibs and parents greater in some regional environments than others. Among non-abstinent twins at age 16, genetic effects influence frequency of consumption and, among those who intoxicate, of frequency of intoxication. These genetic effects are sex-limited and increase with age. Personality scales predictive of adolescent alcohol use (e.g., MMPI Pd), in between-family analyses of twin individuals, directionally predict differences within highly-discordant MZ twin pairs, inviting a search for environmental sources of personality-discordance. Identified from their parents' screening questionnaires, 11-12 year-old twins at elevated familial risk of alcoholism are rated by teachers and peers as more aggressive and less complaint; at age 14, they report that more of their peers use tobacco and alcohol, and they more likely report drinking to intoxication. Such risk-relevant behavioral differences invite genetic analyses as possible precursors of alcohol abuse/dependency.
Address: Department of Psychology, Indiana University, Bloomington, IN, 47405-1301; 812-855-8779, (ph) 812-855-4691 (fax); rose@indiana.edu
1Department of Psychology, Indiana University, Bloomington, Indiana 2Department of Public Health, University of Helsinki, Finland 3Department of Mental Health and Alcohol Research, National Public Health Institute, Helsinki 4Department of Psychology, University of Jyväskylä, Finland 5Department of Public Health, University of Turku, Finland 6Supported by NIAAA (AA 08315, AA 09203, and AA 00145)