The present study sought to provide a better understanding of Black/White differences in growth trajectories for alcohol use. Consistent with past research (Johnston et al., 2006
), Black students were less likely to drink alcohol and consumed less alcohol than their White counterparts. These differences appear to be driven primarily by the initial differences that are present upon entry into high school as the growth rates for alcohol use or amount of consumption throughout high school were not different between these two ethnic groups. Also consistent with our hypotheses, Black students reported fewer close friends who drank alcohol during seventh grade and exhibited a smaller increase in such friends during middle school. Although Black and White students had relatively equal perceptions of the percentage of alcohol consuming peers (GPN) during seventh grade, GPN increased at a faster rate for White students. Replicating findings from other studies (Page et al., 2002
), both groups seemed to overestimate the actual percentage of peers who drink alcohol based on national estimates (Johnston et al., 2006
). To the extent that racial segregation exists for these adolescents, Black and White adolescents may reference different peer groups that might be defined, predominantly, along racial/ethnic lines. Future research is needed to test, for example, whether Blacks attending schools with a greater percentage of White adolescents report higher GPN.
This study provides mixed evidence for our hypotheses that peer norms for alcohol use are not equally salient predictors of alcohol use for Black and White adolescents. The only statistical difference observed between Black and White students was the relation between seventh grade ANF and ninth grade propensity to drink, which, contrary to our expectation, was stronger for Black adolescents. Because having close friends who drink alcohol during seventh grade is less normative for Black adolescents relative to Whites, Black seventh graders who have more close friends who drink may constitute a particularly at-risk group for later alcohol use. Although only one relationship was statistically different for Black and White students, patterns of significance differed between these groups where some relations for peer norms and alcohol use were significant only among White adolescents. Statistically, our findings are generally inconsistent with the theoretical prediction that associations between peer norms and alcohol use would be weaker for Black adolescents made by Wallace (1999)
and with the empirical findings by Newcomb and Bentler (1986)
and by Unger et al. (2001)
. Notably, these studies included larger samples but were not longitudinal, and the study by Unger et al. (2001)
focused on adolescent smoking. Perhaps the effects of peer norms on alcohol use, as well as Black/White differences in these effects, are weaker over wider time intervals.
The strengths of this study notwithstanding, results of this study should be interpreted with some caution given its limitations. First, although the longitudinal design is a strength, this study was correlational (i.e. not experimental), thereby limiting causal inferences. Secondly, all data were based on adolescents' self-reports, which may be subject to inaccuracies—although researchers using self-report, substance use measures have found them to be valid (Newcomb and Bentler, 1986
; Ellickson and Morton, 1999
). A third limitation is that measurement of our key constructs was limited to single-item measures. However, we are minimally concerned by this given that our constructs are sufficiently narrow in scope as to be adequately captured by a single item, though we encourage future research to examine the sensitivity of this study's findings to different operationalizations of peer norms and alcohol use, as well as to different reliability estimates. Additionally, latent growth models account for time-specific measurement error by incorporating error into the residuals. Fourthly, the modest sample size for the Black group might have resulted in insufficient statistical power to detect group differences and was insufficient to test whether gender moderates any of the pathways.
Using a cross-ethnic comparative framework to better understand Black/White differences in adolescent alcohol use is valuable for several reasons (Barrera et al., 1999
). First, it facilitates tests of the cross-cultural universality of theoretical relationships. This study provides mixed support for the notion that peer determinants of adolescent alcohol use for White adolescents are not equally salient for Black adolescents. Secondly, comparative studies can inform policy decisions for resource allocation and prevention targets. Some policy-makers might conclude from this and past studies that alcohol consumption among Black high school students is less problematic relative to their White counterparts and, therefore, requires less attention and resources. However, we believe that this conclusion would be a mistake given that: (a) a substantial portion of Black adolescents do engage in underage drinking, (b) the difference in alcohol use prevalence rates between Black and White groups narrows in young adulthood and (c) Blacks may be more vulnerable to the consequences of alcohol use (e.g. cirrhosis; NIAAA, 2002
). This latter point has especially important public health implications for understanding alcohol-related health disparities. The commonly observed aggregation and interaction of disease in vulnerable and under-served populations, when linked to ‘excess burden of disease in a population’, has been termed syndemic by public health researchers (Singer and Clair, 2003
). Black youth engaged in underage alcohol consumption represent a non-normative subpopulation of Black youth that might experience heightened exposure and enhanced vulnerability to risk factors for alcohol use and/or the relative absence of protective factors relative to their non-using Black counterparts. Given the well-established literature documenting the environmental and socio-economic disparities between Blacks and Whites, it should not be surprising then that this subpopulation of Black youth would experience more severe health and other consequences from their illicit alcohol use. Wallace (1999)
has developed a conceptual framework, premised on the notion that American society is a racialized social system, that might be particularly useful in guiding future such research. Thirdly, it can inform preventive intervention development in whether to be cultural specific or more universal. Our results suggest that preventive interventions that contain social norms education component could effectively reduce underage alcohol consumption for youth in both ethnic groups. Effect sizes may, however, differ between Black and White adolescents and depend on timing and whether the focus is on GPN or ANF. Black adolescents may be on a delayed path to alcohol use development relative to White adolescents, including a lagged path of peer norm influences on alcohol use, perhaps reflecting cultural differences in developmental norms and expectations for substance use. Therefore, in addition to universal social norms-based prevention in middle school, Black adolescents might benefit from additional norms-based prevention later on in middle to later high school, when these influences may be increasing. The notion of developmental sequencing of prevention intervention components may have particular relevance for taking into consideration ethnic and cultural differences in substance use trajectories. Future research should study the socio-cultural mechanisms for which dynamic ethnic/racial categories, such as ‘Black’ and ‘White,’ often serve as a proxy. It is among these mechanisms that we will likely find our strongest explanations for developmental differences in underage drinking between Black and White youth, and most improve our preventive interventions for use with Black youth.