Neuropsychiatrist Dr Marcel Waldinger and Pharmacological Researcher Paddy Janssen came to this conclusion after studying 89 Dutch men with premature ejaculation. Their study also involved a control group of 92 men.
For a month, the female partners used a stopwatch at home to measure the time until ejaculation each time they had intercourse.
"This study applies to men who have always ejaculated prematurely from their first sexual contact onwards and not for men who started suffering from this later on in life," Science Daily quoted Waldinger as saying.
In men with the problem, the substance serotonin appears to be less active between the nerves in the section of the brain that controls the ejaculation.
The researchers say that due to low of serotonin, the transference of signals from one neuron to another does not occur properly in men with the primary form of premature ejaculation.
According to them, a gene called 5-HTTLPR seems to be responsible for the amount and activity of serotonin, which means that it controls the rapidity of ejaculation.
Three types of the gene exist, namely LL, SL and SS.
The researchers have observed that the LL type causes a more rapid ejaculation.
They say that men with LL, on average, ejaculate twice as quickly as men with SS, and also almost twice as quickly as men with SL.
They are trying to identify other genes that are involved in ejaculation.
As long ago as 1998, researcher Marcel Waldinger predicted that both the rapidity with which men ejaculate, and the primary form of premature ejaculation were genetically determined.
"This theory contradicts the idea, which has been common for years, that the primary form of premature ejaculation is a psychological disorder," said Waldinger.
"The results of our research confirm the genetic theory and may contribute to possible gene therapy against premature ejaculation," there searcher added.
The study has been published in the renowned International scientific journal the Journal of Sexual Medicine.