The reason why some women have problems reaching orgasm might be down to their genes, say UK scientists.
By studying 4,000 twins, Keele and London researchers found female orgasm is not all psycho-social as some claim.
This variability might even be beneficial and have evolved to help women find the best male to mate with, they told a Royal Society journal.
Knowing which genes are important could potentially pave the way to drugs to help women orgasm.
The findings also suggest that women who orgasm easily may be satisfied with mates who are less skilled in bed.
Professor Tim Spector and colleagues carried out DNA tests on more than 4,000 women aged 19-83, half of whom were identical and half of whom were non-identical twins.
More : http://news.bbc.co.uk/2/hi/health/4616899.stm