Genetic and environmental contributions to individual differences in alcohol expectancies

One hundred and seventy-six pairs of adult twins (115 MZ pairs, 61 same-sex DZ pairs) completed the Alcohol Effects Questionnaire: a 42-item measure of how people expect to feel following alcohol consumption (e.g. tense/relaxed, clumsy/coordinated, daring/cautious). Item factor analysis yielded nine factors, accounting for 60% of the variance, which were interpreted as representing the expectancies: impaired, happy/secure, sociable, restless, antisocial, aggressive, sensation-seeking, emotional and fearless. A three-factor solution was also fitted to the data, yielding factors interpreted as happy/secure, impaired and activated. Univariate genetic analyses revealed that all but the impairment factors had a significant, though moderate, genetic component. The remaining non-genetic variance for all but one factor was entirely attributable to nonshared environmental factors. The results support previous studies in the area of alcohol use, indicating that some proportion (up to 45%) of the variance in several expectancies concerning alcohol use is attributable to genetic factors.