This prospective study showed that, compared to non-early maturers, early maturers were twice as likely to try cigarettes and were three-and-a-half times as likely to try alcohol. We tested models to explain the relation between pubertal timing and trying cigarettes and alcohol for both boys and girls. For boys, parental monitoring, pubertal timing, and affiliation with deviant peers were independent predictors of trying cigarettes. For girls, the effect of pubertal timing on trying cigarettes was partially mediated by affiliation with deviant peers, and parental monitoring was an independent predictor. For boys, parental monitoring moderated the relation between pubertal timing and trying alcohol, and affiliation with deviant peers was an independent predictor. For girls, the model was similar to that of boys, but affiliation with deviant peers was also a partial mediator of the link between pubertal timing and trying alcohol.
Our findings support previous research on the protective effect of parental monitoring on adolescent substance use, which has been shown to impact substance initiation and use both directly [23
] and indirectly by limiting exposure to deviant peers [21
]. We extended these findings by showing that parental monitoring moderated the effect of early maturation on alcohol use for both boys and girls, such that among early maturers, poorly monitored children were more likely to try alcohol. For cigarettes we found a direct effect of monitoring; for all children, the more they were monitored, the less likely they were to try cigarettes. The protective aspect of parental monitoring may be due at least in part to children who are more willing to open up to parents about their daily activities having a better overall parent-child relationship [15
]. Further examination of monitoring that includes family functioning may disentangle this construct.
We also supported previous research on the association between pubertal timing and affiliation with deviant peers for girls, as early maturing girls were more likely to affiliate with deviant peers compared to non-early peers [6
]. Early maturing girls may be more likely to affiliate with deviant peers because they seek out older peers and boyfriends, as they are more physically advanced than most peers their own age. For boys, affiliation with deviant peers did not vary as a function of their timing, in contrast to findings from some previous studies [25
]. Those studies were on different populations than the present study; specifically on urban, minority children, in contrast to our more rural, Caucasian sample. The impact of early maturation may differ in various social settings.
Girls were more likely to have tried both cigarettes and alcohol by the 8th
grade, and our results show different pathways to cigarette and alcohol use. Early maturing girls were more likely to affiliate with deviant peers than were early maturing boys. Conversely, early maturing boys may achieve a higher status within their current peer group due to their advanced physical maturity and athletic ability [9
]. Early maturing boys may experiment with substances, especially alcohol, as a result of being popular peer group members and leaders; alcohol use tends to occur in groups as a social activity. Although both early maturing boys and girls were more likely to use alcohol and cigarettes, early maturing girls in particular used cigarettes at a much higher rate, and this relation was only partially mediated by affiliation with deviant peers. This high use of cigarettes may be related to body image concerns related to early pubertal onset, as girls may utilize cigarettes as diet aids [35
]. Our disparate findings for boys and girls underscore the need to examine gender and substances separately, as they appear to have distinct initiation and use processes and patterns. In addition, pubertal timing, parental monitoring, and affiliation with deviant peers all had effects on trying substances that were not explained by mediation or moderation, so further exploration of these and other variables is warranted.
There were several strengths of this study. First, the prospective, cohort-sequential study design, beginning at a young age, enabled us to predict trying substances from risk factors measured at a younger age. Second, the stratified random sampling of participants from multiple schools increases the generalizability of our findings. Third, we obtained information from multiple sources (children, parents, and teachers). Fourth, the inclusion of boys and girls allows us to examine gender differences in the early maturation hypothesis. This study also had several limitations. First, although our sample was representative of the community in which it was gathered, participants were primarily Caucasian, limiting the generalizability of the findings to this racial/ethnic group. Second, our measure of pubertal timing was completed by parents, so we assessed the perception of pubertal development rather than actual pubertal development. However, the PDS is widely used, and for these particular research questions the perception of puberty may be more relevant than actual pubertal timing [36
]. Third, our substance use measures were self-report only, and it is possible that participants over- or underreported their use. However, report of lifetime use was consistent across assessments [2
], and participants were assured of their confidentiality. Finally, we may have underestimated parental monitoring by averaging parent reports when they were available from two parents, when one parent may be largely responsible for monitoring the child in each household (i.e., we did not account for family structure which could be related to monitoring). We averaged parent reports for two reasons. First, using two measures increases reliability, and second, in the case of divorced parents, children split their time between two households (and we often have reports from both parents).
Our findings indicate that intervention programs may be especially effective if they are targeted at and designed for early maturing children. Delaying initiation of substances can potentially change an individual’s substance use trajectory over the life span [37
]. Recognizing that early pubertal maturation can place both boys and girls at increased risk for early substance use may be useful for researchers, parents, and teachers, reminding them to pay special attention to early maturers. Further research is necessary to understand the processes leading early maturing girls to affiliate with deviant peers, and to explain the relation between pubertal timing and cigarette use and alcohol use, particularly for boys.