[Paleopsych] NS: Genes blamed for fickle female orgasm
checker at panix.com
Fri Jul 1 01:32:31 UTC 2005
Genes blamed for fickle female orgasm
* 11 June 2005
* Rowan Hooper
IS THIS the ultimate excuse for poor performance in bed? "Sorry,
darling," the man says, just before falling asleep. "It's your genes."
According to a study published this week, up to 45 per cent of the
differences between women in their ability to reach orgasm can be
explained by their genes. Despite decades of surveys and conjecture
about the role of culture, upbringing and biology in female sexual
function, from Freud in 1905 to the Hite report in 1976, this is the
first study of the role of a woman's genes.
Its findings suggest there is an underlying biological basis to a
woman's ability to achieve orgasm. Whether that basis is anatomical,
physiological or psychological remains uncertain, says Tim Spector of
the twin research unit at St Thomas' Hospital in London, who carried
out the study. "But it is saying that it is not purely cultural, or
due to peer pressure, or to differences in upbringing or religion," he
says. "There are wide differences between women and a lot of these
differences are due to genes."
Spector's team asked more than 6000 female twins to fill out a
confidential questionnaire about how often they achieved orgasm during
intercourse and masturbation. They received 4037 complete replies,
which included answers from 683 pairs of non-identical twins and 714
pairs of identical twins. The women's ages ranged from 19 to 83, and
about 3 per cent were lesbian or bisexual.
Only 14 per cent of the women reported always experiencing orgasm
during intercourse. Another 32 per cent of the women reported that
they were unable to achieve orgasm more than a quarter of the time,
while 16 per cent never achieved it at all. Comparing the results from
identical and non-identical twins suggests that 34 per cent of this
variation in ability to orgasm during intercourse is genetic.
The idea behind twin studies is that pairs of twins grow up in similar
environments. So if identical twins are more similar in some way than
non-identical twins, then that similarity must be down to their
identical genes rather than the environment.
Unsurprisingly, more women were able to achieve orgasm through
masturbation, with 34 per cent saying they could always do so.
However, the figure for those who could never achieve it was only
slightly lower, at 14 per cent. The analysis suggests that 45 per cent
of this variation is genetic (Biology Letters, DOI:
Spector says he was surprised by the similarity in the numbers of
women unable to experience orgasm either through intercourse or
masturbation. "With masturbation there are fewer external factors -
i.e. men," he says. "So the higher heritability value for masturbation
gives us a clearer picture of what's going on."
The discovery of a genetic basis for the ability of women to orgasm
raises questions about its evolution. One theory is that it is a tool
for mate selection, the idea being that males best able to bring
females to orgasm are also the best males to help raise children.
Another is that the female orgasm produces movements that increase
sperm uptake, and therefore fertility.
But studies of other primates suggest otherwise. Female stump-tailed
macaques have orgasms too - but mainly during female-female mountings,
which hardly supports the fertility or mate-selection idea.
Bonobos engage in highly promiscuous sex and mutual masturbation,
complete with orgasms, a practice that is thought to promote group
cohesion. This supports yet another theory: that orgasm is important
But even if orgasm does play this role, it cannot be crucial in
humans. The finding that many women cannot achieve orgasm because they
do not have the genes for it shows that the ability to orgasm is not a
trait for which there has been strong evolutionary selection, says
Elisabeth Lloyd of Indiana University in Bloomington, author of The
Case of the Female Orgasm. This supports her theory that as far as
orgasms are concerned, women have been riding on the genetic
coat-tails of male evolution, and that the female orgasm is merely an
accidental echo of the male one, the equivalent of male nipples.
Lloyd says the findings also challenge the notion that the failure to
achieve orgasm represents "female sexual dysfunction", an idea popular
with companies keen to sell to remedies for this so-called disorder.
"What definition of 'normal' could possibly justify labelling a third
of women as 'abnormal'?" she asks.
Even if struggling to achieve orgasm is nothing unusual, Spector says
it might be possible to find ways to make it easier. Though hundreds
of genes could be involved, "that doesn't mean we couldn't find the
genes and pathways, if this was taken more seriously as a problem", he
More information about the paleopsych