4.1. Summary of findings and implications
The goal of the present study was to extend recent research (MacLean & Magid, submitted for publication
) by differentiating the mechanisms of risk for alcohol involvement associated with sensation seeking and impulsivity. In doing so, the study also served as a partial replication of some previous research (Cooper et al., 1995
; Read et al., 2003
; Simons et al., 2005
) by demonstrating the link between disinhibition personality traits, drinking motives, and alcohol-related outcomes. The present study extended the past findings by considering impulsivity and sensation seeking as separate traits assessed by validated scales (MacLean & Magid, submitted for publication
; Schalling, 1978
) and by considering all four drinking motives (Cooper, 1994
). Furthermore, the study provided a formal test of the hypothesized mediational chains using confidence intervals obtained via the bias-corrected bootstrap procedure in order to provide a formal test of the mediational paths (MacKinnon et al., 2004
). Finally, the moderating effects of gender on the proposed model were examined.
Consistent with the hypotheses, findings from the current study demonstrated differential pathways by which impulsivity and sensation seeking are linked to alcohol involvement. Specifically, most (79%) of the effect of sensation seeking on alcohol use was mediated by enhancement motives and the remainder was a direct effect. This is consistent with the theory of optimal level of arousal (Zuckerman, 1994
) and past research (Cooper et al., 1995
; Read et al., 2003
; Simons et al., 2005
). Individuals elevated on the trait of sensation seeking experience low basal levels of arousal, and may be motivated to consume alcohol to achieve an optimal level of stimulation. Alcohol is known to increase positive arousal (Connors & Sobell, 1986
), and therefore, it is not surprising that we found enhancement motives were directly related to alcohol use.
Impulsivity, on the other hand, had no significant direct or indirect effects on alcohol use. Most of the influence of impulsivity on alcohol-related problems was mediated by coping motives (65%) and some of the effect was direct (35%). All of the effects of sensation seeking on alcohol-related problems were mediated by enhancement motives and alcohol use. Enhancement motives were previously found to mediate the relation between sensation seeking and alcohol-related outcomes (Cooper et al., 1995
; Simons et al., 2005
), which suggests that elevated levels of alcohol use will consequently lead to higher levels of alcohol-related problems among sensation seekers. Although, individuals high on the trait of sensation seeking may be motivated to engage in novel, intense, and stimulating experiences like alcohol use to increase arousal, their behavior does not necessarily reflect carelessness, lack of planning, and disregard for consequences, as does impulsivity. That is, sensation seekers may try to minimize negative consequences of their drinking (e.g., not drink before exams), and plan ahead (e.g., pre-arrange a ride home) to some degree. Therefore, very high levels of alcohol use may be necessary before individuals elevated on the trait of sensation seeking experience alcohol-related problems.
The direct and indirect mechanisms by which impulsivity influences alcohol-related outcomes are consistent with the hallmark of impulsivity, often viewed as a preference for quick action and disregard for the long-term negative consequences (Schalling, 1978
). Individuals high on impulsivity appear to rely on quick and easy ways of coping with distress, such as alcohol. Coping drinking motives, in turn, were demonstrated in the current study, as well as in the past research (Cooper et al., 1995
; Lecci et al., 2002
), to be directly associated with alcohol-related problems and to have a stronger effect on drinking problems than other motives. Moreover, the direct impact of impulsivity on alcohol-related problems could be explained by the tendency to disregard possible negative consequences of drinking (e.g., despite an exam the next day) and drinking in risky contexts (e.g., in public places, such as parks, where drinking alcohol is illegal) by those elevated on this trait. Furthermore, such individuals may not plan ahead as they engage in alcohol consumption (e.g., not arranging a ride home, which may result in driving while intoxicated). Finally, high levels of impulsivity may be exacerbated by the disinhibiting effects of alcohol, leading to even more difficulty in regulating impulses (e.g., initiating conflicts and fights). Thus, given a general proclivity toward impulsive behavior, it may not take much alcohol to increase the likelihood of alcohol-related problems, and consequently, levels of alcohol use, may be a less important antecedent of alcohol-related problems for individuals elevated on impulsivity.
The present study examined social and conformity motives as mediators between the personality traits and alcohol-related outcomes. Both impulsivity and sensation seeking were significantly related to social drinking motives. This finding may suggest that there may be limited utility in discerning between impulsivity and sensation seeking in predicting social drinking motives, which could be specific to college students, for whom social aspects of drinking may be particularly important. Social motives, however, were not significantly related to either alcohol use or problems. This may have been because the large amount of shared variance between enhancement and social motives (correlation of .74), left little unique variance to be explained by social motives. As predicted, neither sensation seeking nor impulsivity were significantly related to conformity motives. However, consistent with Cooper (1994)
, conformity motives were significantly related to alcohol problems. Future studies might consider relevant predictors of conformity motives (e.g., self-esteem, social anxiety). It is possible that disinhibited personality traits play a role in the development of conformity motives at younger ages when peer socialization is believed to be particularly strong (Kandel, 1985
). Disinhibited children may engage in drinking in order to conform to their deviant peers, which in turn may result in alcohol-related problems (Dishion, Capaldi, Spracklen, & Li, 1995
). Such a mechanism does not appear to be operating among college students. The utility of drinking motives as proximal predictors of alcohol outcomes was further demonstrated, suggesting that positive reinforcement motives may be better predictors of alcohol use, while negative reinforcement motives may be more important predictors of problematic drinking.
The test of gender moderation revealed only two paths that differed between males and females. Specifically, a path from enhancement motives to alcohol use was stronger for males and the path from alcohol use to alcohol-related problems was stronger for females. Furthermore, it was demonstrated that enhancement motives play an important role in mediating the relation between sensation seeking and alcohol use for males, but not females. Enhancement motives and subsequently alcohol use mediated the relation between sensation seeking and alcohol-related problems for females only. For males, on the other hand, sensation seeking did not play a role in influencing alcohol problems directly or indirectly. These gender differences are partly consistent with the findings of Cooper et al. (1995)
, who reported stronger effects of enhancement motives on alcohol use for males as compared to females. In contrast with Cooper et al. (1995)
, the present study demonstrated the relation between coping motives and alcohol-related problems to be invariant across gender. Cooper et al. (1995)
, however, reported only a difference in magnitude, not in significance or direction of this effect between genders.
4.2. Conclusions and intervention implications
The patterns of findings suggest that narrow constructs of sensation seeking and impulsivity are differentially related to alcohol use and alcohol-related problems, such that impulsivity is more strongly related to alcohol problems, whereas sensation seeking is more strongly related to alcohol use. These results suggest that the prevention and intervention programs may benefit from including different strategies for individuals high on the trait of impulsivity versus sensation seeking based on their respective proximal risk factors for alcohol involvement. Alternative strategies for coping with stress, as well as self-regulation training, might be most helpful for the individuals elevated on impulsivity. In contrast, individuals high on sensation seeking might benefit from learning alternative strategies for increasing positive arousal. Finally, unlike for males, alcohol-related problems for females are more strongly linked to the levels of alcohol use. Therefore, amount of alcohol problems experienced by college females may be more significantly reduced just by monitoring and reducing the amount of alcohol consumption.
4.3. Limitations and directions for future research
The results of the present study should be considered in light of several methodological limitations, such as the reliance upon cross-sectional, self-report data. Although most of the hypothesized relationships are unlikely to be causally reversed, appropriate caution should be exercised in drawing causal inferences from the data. For example, alcohol motives and alcohol outcomes may be reciprocally related (e.g., Stacy, Leigh, & Weingardt, 1994
; Aas, Leigh, Andersen, & Jakobsen, 1998
). In future research, it will be important to replicate the current findings by testing the mediational model in a longitudinal sample to establish temporal precedence.
Additionally, the current sample consisted of predominantly Caucasian (90%) participants, thus restricting the generalizability of the results. It is also important to note that “non-drinkers” were deleted from the analyses based on reported alcohol use in the past 30 days. This criterion may have omitted a small number of participants who were light drinkers and consumed alcohol less than once a month. Thus, the current findings cannot be generalized to these drinkers. Moreover, no information was collected with respect to the diagnostic criteria for alcohol disorders in the current sample. Future studies may want to examine the role of assessments of sensation seeking and impulsivity in diagnosis and treatment planning for individuals meeting criteria for alcohol-related disorders.
It should also be noted that the timeframes provided for alcohol use and alcohol-related problems were different. A three-year timeline was used to assess alcohol-related problems to avoid restricted range of responses because a number of items tend to occur at a low base rate in non-clinical samples. Despite the timeline discrepancy, the obtained correlation of .43 between these two measures is consistent with the moderate association usually found in the literature for adolescents and college students (e.g., correlation of .49 in Cooper et al., 1995
Finally, it should be noted that, guided by the study goals, we chose one of the many definitions of impulsivity that exist in the literature. It is possible that the use of other narrow definitions, such as cognitive impulsivity (Patton, Stanford, & Barrat, 1995
), may result in a different pattern of findings. Even though the present study focused on a more common conceptualization of impulsivity, future research might examine the mechanisms by which other narrow conceptualizations of impulsivity may lead to alcohol involvement.
These limitations notwithstanding, the results of the current study indicate that sensation seeking and impulsivity differentially impact alcohol use and alcohol-related problems and they do so via different pathways (i.e., drinking motives), thus underscoring the importance of distinguishing between the traits of sensation seeking and impulsivity in predicting alcohol-related outcomes among college students. Moreover, the study demonstrated robustness of the results across gender, with only two relationships differing between males and females.