Bad Driving Might be Genetic

The next time you see a bad driver on the road, you could blame genetics, recent research suggests.

Neuroscientists at UC Irvine found that people with a particular gene variant performed more than 20% worse on a driving test than people without it, according to the results published on the university’s Web site. While the sample was small, a follow-up study confirmed the first results.

If the variant really does cause bad driving, it would affect almost a third of Americans. About 30% of Americans have the variant, which limits the availability of a protein called brain-derived neurotrophic factor (BDNF) during activity. BDNF keeps memory strong by supporting communication among brain cells and keeping them functioning optimally. When a person is engaged in a particular task, BDNF is secreted in the brain area connected with that activity to help the body respond, according to the research.

People with the variant “make more errors from the get-go, and they forget more of what they learned after time away,” according to Steven Cramer, neurology associate professor and senior author of the study published recently in the journal Cerebral Cortex.

Previous studies found that, in people with the variant, a smaller portion of the brain is stimulated when doing a task. The researchers wondered whether the variant could affect a common activity such as driving.

The driving test was taken by 29 people (22 without the gene variant and seven with it). They were asked to drive 15 laps on a simulator that required them to learn the nuances of a track programmed to have difficult curves and turns. Researchers recorded how well they stayed on the course over time. Four days later, the test was repeated.

Results showed that people with the variant did worse on both tests than the other participants, and they remembered less the second time. “Behavior derives from dozens and dozens of neurophysiologic events, so it’s somewhat surprising this exercise bore fruit,” Cramer said.

A test to determine whether someone has the gene variant is not commercially available, according to the research.

“I’d be curious to know the genetics of people who get into car crashes,” Cramer added. “I wonder if the accident rate is higher for drivers with the variant.”