"Delinquency and aggression put adolescents at risk for many negative outcomes in the future, including lower educational achievement, substance abuse, depression and problems in relationships," according to Dr. Sylvie Mrug, PhD, Associate Professor of Psychology at the University of Alabama at Birmingham and lead author of this current study.

Thus it is important to understand how these problem behaviors develop and how pubertal timing and friends' behavior, among other variables, contribute to them,” Dr. Mrug comments.

Dr. Mrug and colleagues conducted a longitudinal study to determine how puberty and peer deviance relate to trajectories of aggressive and delinquent behavior in early adolescence and whether these relationships differ by race/ethnicity.

For this study, 2607 girls from three metropolitan areas and their parents were interviewed at ages 11, 13, and 16 years. Girls reported the onset of their first menstrual cycle, best friend’s deviant behavior such as lying and talking back to adults, delinquency and physical and non-physical aggression. Parents provided information on family sociodemographic characteristics and girls’ race/ethnicity.

Among the girls, 16 percent reported early puberty as determined by onset of menarche before age 11 years.

Overall, relational and nonphysical aggression increased from age 11 to age 16, whereas delinquency and physical aggression remained stable.

Early puberty was linked with higher rates of delinquency and physical aggression at age 11. Over time physical aggression had decline but not delinquency.

Girls with a best friend with behavior problems were linked with higher levels of all problem behaviors, but the effect lessened over time for most outcomes.

Early puberty was linked to a stronger association between best friend’s negative behavior and delinquency. According to researchers this suggests an increased vulnerability to negative peer influences among girls with early puberty.

The results also showed that most of the relationships between early puberty, friends' behavior and aggression and delinquency are the same across race and ethnicity.

In their conclusion the researchers write, “Early puberty and friends’ deviance may increase the risk of problem behavior in young adolescent girls. Although many of these associations dissipate over time, early-maturing girls are at risk of persistently higher delinquency and stronger negative peer influences.”

According to Dr. Mrug, “These influences can be short-lived, and this may give hope to families dealing with such issues.”

It is important to have more studies that follow girls and boys from childhood through adolescence and into adulthood to see how much different risk factors matter in the long-term, says Dr. Mrug.

The team notes further study is needed to examine other relevant risk and protective factors such as social support or parenting influences.

This study appears in the journal Pediatrics.

Citation

Slideshow Problems of Early Puberty