Methods: Data for this study come from the Project on Human Development in Chicago Neighborhoods (PHDCN), a longitudinal sample of youth conducted over a period of seven years. The PHDCN study randomly sampled participants within block groups from 80 neighborhoods in Chicago. This study includes interview data for a single cohort of youth interviewed at ages 12, 15, and 18 over three waves of the PHDCN (n =725). An ordinal-level measure of aggression based on counts of aggressive behavior and alcohol-use based on number of drinks consumed were used to estimate latent trajectory classes using these two growth process. Growth mixture models were estimated using two intercept and two slope factors and included sociodemographic covariates (race/ethnicity, income, gender and parental educational attainment) to test for differences in the composition of dual trajectory classes. Models also adjusted estimates for nesting of children within neighborhoods.
Results: Using comparative measures (AIC, BIC, ABIC, and entropy) as well as substantive theory, a three class model provided best fit. A normative class, Low Risk Development (LRD) (n=453) displayed low levels of heavy alcohol use and low levels of aggression at all time points based upon lower probability of endorsing higher levels of both aggression and alcohol use. A combined high risk (CHR) (n=79) group displayed higher levels of aggression and also higher alcohol use risk over time, and a third group, aggressive high risk (AHR) (n=193) displayed comparatively high risk of aggression, but lower risk of alcohol use. Boys were more likely to be in both of the high risk classes, CHR (OR=2.77; p=.001) and AHR (OR=3.91; p=.005) than in the low risk group. Black race was associated with much greater likelihood of being in the AHR group (OR=42.35; p=.005). Greater income was associated with greater odds of being in the CHR group (OR=2.05; p=.001).
Conclusions and Implications: Our findings suggest that heterogeneity in the process of development of alcohol and aggression during adolescence. Among Black adolescents, there may not be a link in the development of aggression and alcohol risk, while higher levels of income may be associated with a dual risk profile. Further research could consider the role of differing social norms among youth based on peer and neighborhood characteristics, with the goal of creating tailored intervention efforts.