Teens drive irresponsibly — except when Mom is riding shotgun, study says

Posted at 4:21 PM, May 04, 2015
and last updated 2015-05-04 18:10:21-04

But ma, I wanted to run that light!

Teenagers are more likely to make irresponsible decisions behind the wheel – except when mom is riding shotgun, according to a new study on the teenage brain.

“Being risky, it appears, is no longer rewarding in the presence of mom,” said University of Illinois study author Eva Telzer in a statement.

Every day, seven teens die in a car crash in the United States, according to the Centers for Disease Control and Prevention. That’s 2,650 teens killed and almost 292,000 treated in the ER each year.

For the study, 14-year-olds rode a simulated driving course while their brains were scanned by a functional MRI, which shows which parts of the brain are active.

The faster the teens finished the course, the more money they got at the end of the experiment.

While driving alone, the teens were more likely to run a yellow light — a reckless decision that risked a simulated crash. Running the light activated a thrill-seeking, rewarding part of the brain called the ventral striatum.

But when their mothers were present, the teens drove more responsibly. The part of their brain involved in decision making and control — called the prefrontal cortex — became more active.

Instead of seeking a reward, the teens were thinking it through. Thanks, mom.

“A parent's presence is actually changing the way the adolescent is reasoning and thinking about risk — and this increases their safe behavior,” Telzier said.

Having a parental influence is essential for teens because they lack experience or a fully developed brain, said University of Michigan pediatric trauma surgeon Peter Ehrlich.

“The areas of the brain that continue to develop are those related to judgement and decision making,” Ehrlich said. “At 16 you know everything — at least you think you do.”

The brain fully matures at around age 27, he said. Until then, teens are susceptible to car crashes and other risky behavior.

“For adolescents, the number one reason they’re admitted to our hospitals is a car crash,” Ehrlich said, with about 30 to 40 percent linked to distracted driving, alcohol or substance abuse.

The risk goes down when children have good role models, he said. So while Mom or Dad may not always be in the driver’s seat, their behaviors might be.

“Parents should look at themselves in the mirror and see how much what they do will influence what their kid does in the car,” Ehrlich said. “[Teens] will look and see if they really have to do it.”

Gavin Stern is a national digital producer for the Scripps National Desk.