Minor stress may be useful for teenagers who learn to drive. In a new study, teens whose levels of the stress hormone cortisol increased more during times of stress got into fewer car crashes or near crashes in their first months of driving than their less-stress-responsive peers did, reports Fox News.

Automobile accidents are the No. 1 cause of death of teenagers in the United States, according to the Centers for Disease Control and Prevention. Car crashes also kill more 15- to 29-year-olds globally than any other cause, according to the World Health Organization. 

For the study, Marie Claude Ouimet, a professor of community health at the University of Sherbrooke in Quebec, and her colleagues recruited 42 teens in Virginia, and fitted their cars with video cameras, accelerometers, GPS and mileage recorders to record the teens' crashes and near misses during their first 18 months of driving.

The results revealed that the more responsive a teen's cortisol levels were to stress, the fewer crashes and near misses they experienced.

The findings suggest teens' stress responses are linked with their risk of getting into accidents, wrote Dr. Dennis R. Durbin, of the Center for Injury Research and Prevention at The Children's Hospital of Philadelphia, and colleagues in an editorial accompanying the study.