Are Peer Influences During Early and Mid-Adolescence Correlated with Different Latent Classes During Emerging Adulthood?

BACKGROUND AND PURPOSE:   The purpose of the study is to explore how peer influences during middle and late adolescence affect patterns of property offenses, violent offenses, and substance use as emerging adults (18-25 years old). 

Negative peer influences have been associated with increased illegal behaviors since the earliest studies of delinquency (Shaw & McKay, 1969; Short Jr., 1957).  However, a limitation of the extant literature is that most studies regarding illegal behaviors have either focused on one type of behavior, such as violent or property-related offenses, or have created a scale that fails to capture the interrelationships of problematic behaviors. This gap in the literature hinders the development of effective prevention and intervention strategies.

This study’s research question is: Are peer influences during early and mid-adolescence correlated with different latent classes during emerging adulthood?

METHODS: The sample included 8276 participants (18-25 years old) from Wave III (2002) of the National Longitudinal Study of Adolescent Health (Add Health). Illegal and substance use behavior measures included five questions regarding property offenses, six questions regarding violent offenses, and 12 questions regarding substance use and abuse ranging from tobacco use to cocaine use. Covariates included gender, race, age, neighborhood safety, gang involvement, peer smoking, peer drinking, peer marijuana use, and unstructured time spent with peers. Latent class analysis (LCA) is a person-centered analytic approach that generates empirically based typologies by generalizing information to persons instead of variables. Following the LCA variables were regressed onto the latent classes. MPLUS 6.1 was used for analyses.

RESULTS: Four classes resulted: illegal behaviors (13.65%), substance abuse (31.10%), substance use, (16.97%) and normative behaviors (38.29%).  Illegal behavior class members were 7.43 (p<0.001) times more likely to be male, and 33% (p<0.05) less likely to be African American/black than the normative class.  Unstructured time with friends during Wave II (late adolescence) increased the risk of illegal behavior class membership. For each SD increase in unstructured time with friends during Wave II, the odds of illegal behavior class membership, as compared to the normative class, increased by 31% (p<0.001).  For each SD increase in friends who drank during Waves I and II, the likelihood of illegal behavior class membership, compared to the normative class, increased by 22% (p<0.05) and 47% (p<0.001) respectively. Substance abuse class members were more likely to be younger (20%, p<0.001), and less likely to be African American/black than the normative class.  Living in a low crime neighborhood raised the risk of problematic substance abuse class membership by 46% (p<0.001).  For each SD increase in unstructured time with friends during Wave II, substance use class membership, compared to the normative class, increased by 25%.   Finally, each SD increase in friends who use marijuana during Waves I and II increased the likelihood of being in the substance use class by 29% (p<0.01) and 33% (p<0.001) respectively.

STUDY IMPACT: Study results underscore the importance of peer relationships during adolescence, as well as the need for effective intervention strategies to prevent illegal and substance abuse behaviors during emerging adulthood.