Teenagers who self-report feeling drowsy at mid-afternoon have been found more likely to behave anti-socially by lying, cheating, stealing and fighting. Further research from the University of Pennsylvania and the University of York in the United Kingdom found that those teens also are 4.5 times more likely to commit violent crimes as adults.

“It’s the first study to our knowledge to show that daytime sleepiness during teenage years [is] associated with criminal offending 14 years later,” said Adrian Raine, the Richard Perry University Professor with appointments in the departments of criminology and psychology in the School of Arts & Sciences and the department of psychiatry in Penn’s Perelman School of Medicine. 

Dr. Raine and Peter Venables, emeritus psychology professor at the University of York, published their findings in the Journal of Child Psychology and Psychiatry. 

The data for the study was collected by Dr. Raine as part of his PhD research 39 years ago, studying under Dr. Venables, but had never been analyzed. For this research, he tested 101 15-year-old boys from three secondary schools in the north of England. Participants underwent a lab session from 1-3 p.m. and then were asked to rate their degree of sleepiness on a 7-point scale, with 1 being “unusually alert” and 7 being “sleepy.” Dr. Raine also measured brain-wave activity and sweat-rate responses to stimuli, to determine brain-attentional function.

He then collected data about anti-social behavior, using self-reports from participants and reports from teachers who had worked with the teens for at least four years. 

Last, Dr. Raine conducted a computerized search at the Central Criminal Records Office in London to find out which of the original study participants had criminal records at age 29. The study excluded minor violations, focusing instead on violent crimes and property offenses and only those crimes for which participants were convicted. 

The results showed 17 percent of participants had committed a crime by that point in adulthood.

After considering study participants’ socioeconomic status, Dr. Raine found a connection. 

“Is it the case that low social class and early social adversity results in daytime drowsiness, which results in inattention or brain dysfunction, which results 14 years later in crime? The answer’s yes,” he said. “Think of a flow diagram from A to B to C to D. Think of a chain. There is a significant link.”

He further explained, “Daytime drowsiness is associated with poor attention. Take poor attention as a proxy for poor brain function. If you’ve got poor brain functioning, you’re more likely to be criminal.”

This knowledge could potentially help with a simple treatment plan for children with behavioral issues: Recommend they get more sleep at night.

“That could make a difference not just for anti-social behavior at school with these teenage kids but more importantly, with later serious criminal behavior,” Dr. Raine said. “More sleep won’t solve crime, but it might make a bit of a dent."