University of California Irvine neurologist Dr. Steven Cramer did a study that showed that bad driving may have a genetic basis. People with a certain gene variant performed more than 20 percent worst in learning a new driving course in a simulator than person without the gene variant.
29 subjects was asked to learn a new driving course by being placed in a driving simulator and drive 15 laps consisting of difficult curves and turns. The subjects re-did the driving test 4 days later. Of the 29 subjects, 22 did not have the gene variant and 7 of them did. The subjects with the gene variant did worst in both tests. Dr. Cramer said “These people make more errors from the get-go, and they forget more of what they learned after time away.”
How a Particular Gene Variant Causes Bad Driving
BDNF is brain-derived neurotropic factor. This protein plays a role in memory and communication between cells. UC Irvine article says “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.”
When a person performs a motor-related task such as driving for example, BDNF is secreted to the relevant area of the brain for that activity.
However, people with this particular gene variant known as Val66Met does not secret as much BDNF. They make more errors in the initial learning and they retain less.
The study was published online in Cerebral Cortex on September 10, 2009 was titled “BDNF Val66Met Polymorphism Influences Motor System Function in the Human Brain”.
The study abstract says “A single nucleotide polymorphism for this growth factor, val66met, is common and associated with decreased activity-dependent BDNF release.”
It further says “subjects with the polymorphism showed smaller activation volume within several brain regions as compared with subjects without the polymorphism.” The conclusion is that “subjects with the polymorphism showed greater error during short-term learning and poorer retention over 4 days, relative to subjects without the polymorphism.”
How common is this gene variant? Almost 30% of American have this gene variant. At the time of the study, there are no commercial test for this gene. So it is hard to say who has it.
Limitation of the Study
It is important to note that the study has only a sample size of 29. And the study involves motor-learning skills in driving a new course in simulator. It does not take into account driving experience and attention to driving in real-world automobiles and roads.
In fact Cramer says “I’d be curious to know the genetics of people who get into car crashes … I wonder if the accident rate is higher for drivers with the variant.”
 University of California Irvine: “Bad Driving may have genetic basis“
 CNN: “Blame genetics for bad driving“
 Cerebral Cortex: “BDNF Val66Met Polymorphism Influences Motor System Function in the Human Brain“