Early puberty in girls could trigger problem-child behavior, according to a recent study.
Researchers at the University of Alabama at Birmingham found adolescent girls who experience their first menstrual cycle before the age 11 reported more delinquent and physically aggressive behavior. Based on the study, by the age 16, the effect of early puberty on physical aggression disappeared, but these girls still reported more delinquent behavior than those who did not experience early puberty.
"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," the study's lead author Dr. Sylvie Mrug, associate professor in the UAB Department of Psychology, said in a statement. "Thus it is important to understand how these problem behaviors develop and how pubertal timing and friends' behavior -- among other variables -- contribute to them."
For the study, Mrug and her colleagues interviewed and followed more than 2,600 girls and their parents. They interviewed them three times while they aged from 11 to 16 to examine how early puberty onset and best friends' problem behavior, like talking back to adults, lying, cheating and not being nice, contributed to delinquency and different types of aggression over time, according to a press release.
They found that girls who had a best friend with a problem behavior tended to be more delinquent and aggressive behavior at age 11, but these effects mostly dissipated by age 16
"This suggests that negative peer influences from best friends at age 11 are short-lived, perhaps because best friends change as children enter middle school," Mrug said. "The most interesting finding was that girls who experienced early puberty reported more delinquent behavior if their best friend was more deviant."
The results from this study suggest that girls who mature earlier are more vulnerable to negative peer influences.
"It is important for parents and other adults to monitor who the friends are and what the girls do with their friends," Mrug said. "Of course this is important for all children and adolescents, but it may be even more critical for girls who mature early, as they are more vulnerable."
In a press release, Mrug said 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.
