Though unmanned technology may soon solve the problem of reckless and dangerous driving, scientists continue to glean new physiological insights into the human animal behind the wheel.

In studying teenage drivers, investigators at the University of Sherbrooke in Quebec find that kids with a higher response to stress experienced fewer crashes and mishaps on the roads and highways. Previous research had implicated certain neurobiological processes in risk-taking behavior, investigator Marie Claude Ouimet says. Now, new data shows the body’s response to the stress hormone cortisol may greatly influence driving behavior among adolescents and young adults.

"This study found that cortisol, a neurobiological marker, was associated with teenaged driving risk [and that] teenagers with lower response to stress were at higher risk for [crashes and reckless driving charges],” Ouimet said in a statement. “As in other problem-behavior fields, identification of an objective marker of a specific pathway to teenaged driving risk promises the development of more personalized intervention approaches."

As “unmanned” technology builds in today’s new cars, scientists and engineers hope to find increasingly more synergy between man and machine moving forward. Crash fatalities are the leading cause of death worldwide for young people ages 15 to 29, with the first few months after licensure a particularly dangerous time for new drivers.

Ouimet and her colleagues tested the link between cortisol response and dangerous driving under laboratory conditions with a “stress-inducing” task — math problems — to measure levels of the hormone. They then compared that cortisol data to rates of reckless driving charges incurred by a sampling of 40 newly licensed drivers, including 19 boys and 21 girls who were all age 16 at the time.

Over time, the researchers measured cortisol levels by taking saliva samples from study participants on a periodic basis, while observing the drivers behind the wheel with cameras and sensors installed in their cars. Perhaps not surprisingly, kids with a higher response to cortisol — those cooler under pressure — experienced fewer crashes or reckless driving charges. Those results held evenly for boys and girls.

Co-investigator Dennis R. Durbin, a doctor at the Children’s Hospital in Philadelphia, said the study findings demonstrate the need for continued research on the effects of cortisol on teenage driving behavior.

"The most immediate implication of the findings of the Ouimet et al study is for continued research to better characterize the relationship between cortisol reactivity in response to stressors and crash risk in the general population of healthy teens and among those teens who might be at higher crash risk owing to preexisting conditions or history of risky behaviors," he said in the statement.

In the meantime, parents of teenage drivers should consider driving as a health-related behavior, given the significant risk of death and injury to adolescents.

 

Source: Ouimet MC, Brown TG, Durbin DR, et. al. Higher Crash and Near-Crash Rates in Teenaged Drivers With Lower Cortisol ResponseAn 18-Month Longitudinal, Naturalistic Study. JAMA Pediatrics. 2014.