Various external factors have been attributed to premature ejaculation; peer pressure, intoxication, stress, nervousness, and lack of confidence. But increasingly the role of human genetics is being explored to explain why some men ejaculate early.
In 2008 a study by scientists from Utrecht University in the Netherlands linked premature ejaculation with a serotonin transporter gene. Serotonin is a neurotransmitter which regulates moods, sleep, appetite, and sexual activity. Researchers studied 89 men who suffered from the primary form of premature ejaculation, which means that have had the problem since their first sexual contact. They were compared with men who had no history of the condition. What they found was that in men who ejaculated prematurely the neurotransmitter was less active in the part of the brain that controls the physiological mechanism.
A previously discovered gene - 5-HTTLPR - had already been linked with the amount and activity of serotonin. There are three versions of the gene - SS, LL, and SL. The Utrecht study found that men with the LL genotype ejaculated twice as rapidly as those with the SS genotype.
Further support for the idea that premature ejaculation might be a genetic disorder came from a study by scientists in Turku, Finland in May 2009. It appeared in Journal of Sex and Marital Therapy. Scientists surveyed 3,000 males, all twins, and their older and younger brothers about the first time they had sex. The fact that so many men from such a large data sample reported problems with their first sexual encounter was seen as evidence of some kind of genetic link.
