Small Girl Sleeping According to a new study, a preference for nighttime over daytime activities may be associated with anti-social behavior in adolescences, even in children as young as eight years old.

Those who prefer later bedtimes appear to exhibit more antisocial behavior than those who like to wake up early and participate in daytime recreational activities.

Study co-authors Elizabeth J Susman, of Pennsylvania State University said that staying up late “contributes to lack of sleep and this, in turn causes problems such as lack of control and attention regulation, which are associated with antisocial behavior and substance use.”

Susman and her team investigated the relationship between a preference for morning versus evening activities and antisocial behavior in 111 subjects between 8- to 13-years-old. They also correlated morning to afternoon cortisol levels with behavior and noted the age at which the subjects reached puberty.

The researchers found a number of factors were related to antisocial behaviors in the study group, particularly in the boys who tended to exhibit more rule-breaking behaviors than did their peers. The findings are published in the Developmental Psychology journal.

In the case of girls, a preference for evening activities was associated with a higher incidence of relational aggression or aggressive behavior towards their peers.

Boys who experienced prolonged high levels of cortisol- smaller decreases in cortisol levels from time of awakening until 4pm- tended to have more behavior problems than did their peers. However, this was not true for girls.

Normally, levels of cortisol, the stress hormone associated with circadian rhythms, peak in the morning upon awakening and plateau during the afternoon and evening hours.

Boys who hit puberty at earlier ages tended to also engage in more rule-breaking and attention behavior problems than did other boys, according to parent reports, and they self-reported more symptoms of conduct disorder. Girls who were younger at puberty reported more relational aggression compared with their peers, study findings indicate.

Overall, the findings imply that “caregivers should be vigilant to bedtime activities of children and young adolescents,” Susman said.