DRINKING BEHAVIOUR AND DRINKING MOTIVATIONS IN EMERGING ADULTHOOD: HOW DO OUR ROMANTIC RELATIONSHIPS AND FRIENDSHIPS AFFECT OUR ALCOHOL USE?

Abstract

In my dissertation, I sought to better understand how social influence and drinking motivations impact drinking behaviour within close interpersonal relationships. I focused on the developmental period of emerging adulthood as this developmental phase is associated with increased risk of alcohol misuse. Moreover, I focused on two important close interpersonal relationships during this developmental period: romantic couples and drinking buddies (i.e., an individual someone chooses to drink with). The five-factor model of drinking motivations suggests individuals drink to achieve desired outcomes from their drinking. Each motive is associated with different alcohol use patterns: enhancement (to experience pleasure), social (to increase social affiliation), conformity (to reduce negative peer pressure), coping-anxiety (to reduce anxiety) and coping-depression (to reduce negative affect). While drinking motives have been investigated extensively among individuals, no research had investigated drinking motives within these important close relationships. Study 1 expanded the extant literature by evaluating whether drinking motives as well as drinking behaviours were similar among members of N = 203 romantic couples. Couples were found to be similar in both their drinking motives and drinking behaviours and drinking behaviour similarity was related to how often the couples spent time drinking together as well as how often they spent face-to-face time together. Study 2 expanded Study 1 by investigating the degree to which romantic couples influence one another’s drinking behaviour via drinking motives. Utilizing the same four-wave, four-week data collected in Study 1, multilevel Actor-Partner Interdependence Models (APIMs) were utilized in Study 2 to investigate the influence drinking motives had on partner drinking both over time and when averaged across time. Partner positive reinforcement motives (enhancement and social) as well as coping-anxiety motives, positively predicted individual drinking quantity both over time and when averaged across time. This finding suggested that romantic partners’ drinking motives conferred influence on the drinking of individuals. Moreover, this influence was mediated by change in individual drinking motives. That is, if a partner drank for social motives, that influenced the individual to drink for social reasons, which in turn influenced the individual’s drinking quantity. Study 3 contained a different dyadic sample and was novel in its investigation of drinking motives within drinking buddy relationships (N = 174 dyads). Utilizing a four-wave, four-month design, multilevel APIMs were utilized to investigate drinking buddy influence and to replicate and extend findings from Study 2 into another important dyadic relationship. Partially replicating Study 2, partner positive reinforcement motives and coping-anxiety motives predicted individual drinking frequency over time. Social motives also mediated partner influence. Supplemental analyses showed that along with romantic couples, drinking buddies were also similar in their drinking motives and drinking behaviours. Taken together, my studies suggest that drinking motives exert influence on alcohol use not just within individuals, but between individuals in close relationships (romantic or friendships). This social influence may result in increased drinking behaviour over time, and therefore suggests that drinking motives may be important targets for both individual alcohol use treatment and for couples or network therapy.