Impulsive in nature? Parents to be blamed

If your child is impulsive, do not blame him or her. It is something that may have been inherited from you as new research has linked such behaviour with "impulsivity" genes.

"Delay discounting" is the tendency strongly influenced by our genetic makeup.

It gradually improves as teenagers get older and when given the choice, to take a smaller reward that is available immediately, instead of a larger reward that will be delivered in the future.

Identifying the "delay discounting" genes are important for understanding the basis of psychiatric disorders, especially addictions and other disorders that involve impulsive decision-making.

For this, Andrey Anokhin and his colleagues from the Washington University's school of medicine did a study of 602 twins.

The results suggest that "delay discounting" gradually improves as teenagers get older -- such that 18 year-olds have a greater ability or tendency to wait for the larger delayed reward, as compared to younger teenagers.

Apart from age, genes accounted for about half of the difference among individuals in their level of delay discounting.

Many genes are likely to influence "delay discounting" and the data suggest that these "impulsivity genes" may include genes coding for enzymes that synthesise the neurotransmitter serotonin and receptors where serotonin binds in the brain.

"While it is tantalising to speculate that the associations between delay discounting and serotonin-related genes may ultimately point the way to new treatments for addictions and other disorders involving impulsive choice," Anokhin said.

The report was presented at the American College of Neuropsychopharmacology annual meeting in Hollywood, Florida this week.