Researchers in London have determined arousal and orgasm in women depends largely on genetic factors, the same as migraine and depression.
Professor Tim Spector of St Thomas' Hospital led the study of almost 1,400 pairs of female twins, and said the elusiveness of the female orgasm is evolved, probably because it confers a reproductive advantage that is triggered only with a particularly desirable partner.
The survey found while 14 percent of the women had an orgasm every time they had sex, 16 percent had never reached a climax this way and another 16 percent seldom did.
Genes were found to be responsible for 34 percent of this variation, indicating inheritance is the single most important factor in women's capacity to orgasm.
"What these results show ... is clear evidence that biology is an underlying influence here," Spector said.
The study was published Wednesday in the journal Biology Letters.
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