The effects of alcohol expectancies on drinking behaviour in peer groups: observations in a naturalistic setting.

AIMS To study the functionality of alcohol expectancies in predicting drinking behaviour in existing peer groups of young adults in a 'naturalistic' setting. DESIGN AND SETTING Young adults were invited to join an experiment with their peer group in a bar annex laboratory. During a 'break' of 50 minutes in this experiment, their activities, social behaviour and drinking behaviour were observed with digital video and audio equipment. PARTICIPANTS Twenty-eight peer groups were involved in this study. A peer group consisted of seven to nine people, with relationships ranging from intimate relations and close friendships to being acquaintances. A total of 238 participants were involved. Measurements Information of the drinking behaviour from observations and questionnaire data on alcohol expectancies provide the opportunity to look at how and which expectancies are related to actual drinking patterns. Multiple regression and multi-level analyses were applied. FINDINGS Expectancies on the positive and arousing effects of alcohol consumption were related to alcohol consumption in a naturalistic, social drinking situation, in addition to group effects of drinking. Expectancies on the negative and sedative effects of drinking, however, were not related to drinking. CONCLUSIONS The findings indicate that among young adults observed in a peer group and naturalistic drinking setting, positive expectancies about the effects of alcohol and expectancies about the effects of alcohol on arousal are related positively to drinking level.