Researchers believe that early or late timing of puberty in adolescents boys can trigger chemicals medically associated with anti-social behavior.
"Aggressive behavior can begin very early, even in pre-school, and might be related to poor impulse control, difficulties in the family or just overall general problem behavior," said Elizabeth J. Susman, the Jean Phillips Shibley professor of biobehavioral health, Penn State. "We wanted to find out if earlier or later timing of puberty in adolescents has any biological factors related to it."
To reach the conclusion, Susman and her colleagues looked at how the timing of puberty affects cortisol, a stress hormone, and salivary alpha amylase, an enzyme in saliva used as indicator of stress.
The findings appear in the May issue of Psychoneuroendocrinology.
The researchers found that lower levels of the alpha amylase in boys who experienced earlier maturity and higher levels of cortisol in boys who experienced later maturity are related to antisocial behavior. They found no similar correlation in girls.
"This is the first study to show that the timing of puberty moderates biological risks of antisocial behavior," said Susman. "The implication that parents should be especially sensitive to picking up signs of earlier or later puberty in their children. "Parents and healthcare providers should be aware of how puberty can be stressful -- behaviorally and biologically -- on the kids."
Why the findings are statistically significant for boys and not girls remains unclear.
"At puberty, boys produce a lot of testosterone and testosterone is a stress hormone as well," added Susman. "It may be that compared to girls, boys just have more biological hormone changes that may lead to antisocial behavior."