Some people argue that the female orgasm in humans is vestigial, a leftover，belonging more to the other sex – in much the same way nipples on male chests ostensibly serve no biological purpose.

Dr. Elizabeth A. Llyod, for instance, professor of biology at Indiana University, in her book “The Case of the Female Orgasm – Bias in the Science of Evolution” argues this very point. She concludes that it is the expectations of male researchers in the evolutionary field that distorts conclusions on female sexuality, and that the female orgasm is a male leftover that is somewhat meaningless and basically still there ‘just for fun’.

A conclusion such as this couched in this manner is tenuous at best。Aside from the supposition that nature, under the pressure-cooker selectivity of an African setting, had the luxury of dabbling in ‘fun’， if the female orgasm exists ‘just for fun’ then it is still there for a reason (that reason being to cause fun) – and therefore must have evolved to be there。It is an inescapable loop of logic, and besides, if we accept natural selection on one level then we have to accept it on all levels – the female orgasm was either selected or it wasn’t。

The vestigial example nominated by Lloyd (male nipples）is a bad choice – when stimulated, male nipples often produce strong sexual arousal in men, encouraging them to seek sex – another left-over ‘accident’ of nature? The only thing that is obvious is that we evolved to have fun when having sex – intercourse in humans is definitely recreational as well as functional。

Pekka Santtila of the Abo Akedemi University，Finland, and Australian geneticist Brendan Zietsch， undertook an exhaustive study using 1,803 pairs of opposite sex twins and 2,287 pairs of same sex twins，asking all subjects to report upon their frequency of orgasms。Their conclusion？“The evolutionary basis of female orgasm is both important and unknown。Much more work needs to be done。”

Of course we could just ask men why they feel that giving a woman an orgasm during intercourse is important – that it makes them feel far more connected to their mate – i.e. that it may be all about pair bonding，might be too simplistic。That men instinctively derive pleasure from a female climaxing and that it is often the subject of pleasurable male to male sexual discussions, might also seem too obvious。That our bonobo cousins (our nearest primate relative) and highly social，large-brained dolphins are the only other animals known to have evolved female orgasm，animals that depend heavily on pair bonding for the care and protection of ‘learning’ offspring with extended infancies, might also be just too in-your-face obvious。

On the other hand, and as we all know, orgasm does not occur every time a woman has intercourse and around 10% of women never experience it during their lifetime. So the question – why does female orgasm exist? is valid, not because it occurs, but because it does not occur uniformly as in men and that it sometimes does not occur at all.

Christopher Ryan, a psychologist and the author of the ground-breaking work，“Sex at Dawn” points out that there is far more happening both physically and mentally during intercourse than meets the eye. Ryan proposes that, just like our bonobo cousins female humans in their natural environment mate with numerous members of the opposite sex. Rather than always having intense physical battles over females，males also adapted to ‘duke it out’ using their sperm.

In the book “Sperm Wars: Infidelity, Sexual Conflict, and Other Bedroom Battles” Robin Baker points out that around 83% of sperm are killers, which attack and destroy the sperm belonging to other males within the female. Blocker sperm make up around 16%, and try to block entrance to the female egg from other sperm, while the remaining 1% of sperm are egg getters, the ones that actually do the fertilizing.

Ryan also points out that it is not just to do with warring sperm, but that the female anatomy also plays a key role in selecting which particular sperm gets through. When a woman orgasms it creates a change in the ph level within the uterus, thereby making the path to the egg far more ‘friendly’ for sperm erupting from the male she is having intercourse with at the time.

Ryan further stipulates that regardless of any lingering sperm from another male, the egg can still help select one sperm over another. How it does this is still somewhat of a mystery, but it is clear that preference for one particular sperm can be ‘encouraged ’ (not to be confused with ‘chosen’）by the egg.

So one might reasonably ask, why would nature have evolved such a complex selective process? The obvious answer is that it is in order to produce the best possible outcome. But what is that outcome?

Asexual reproduction is a female giving birth to another female。Sex was invented in order to keep up with the phenomenal reproduction rate，and therefore mutation rate，of single cell invader organisms。 As multi-celled animals are far larger and more complex they cannot hope to match the reproduction/mutation rate of single cell organisms。Sex，however，between a male and female， provides a 100% mutation in only one generation。That，plus an immune system，is how multi-celled animals matched the mutation rate of single cell invaders。

Logically，it is in the best interests of the DNA residing in the egg to be choosy about which (invading）DNA it encourages to penetrate to the inner sanctum. It will be looking to mix with the DNA which is most unlike itself, and in that way it can give the next generation the widest genetic variation possible, thereby making it more adaptable to ever-changing environments and conditions.

So why do women only have orgasms sometimes? For a start, although helpful, a female orgasm is not vital to the reproductive process, whereas male orgasm is – no sperm，no baby. Secondly, the female may not be all that enamored with the male she is mating with at the time. He may not smell right (detecting pheromones is the body’s first way of identifying DNA variance and women are highly sensitive to it, consciously and subliminally) or he may not be acting in a manner which suggests he would make a good long-term father to offspring. The emotional ingredient is not present and the woman is not in the right frame of mind to experience an orgasm.

Overt emphasis on monogamy in Western cultures does not help. It means the stimulation of mating with numerous males，and thereby getting the widest choice of available DNA，is absent and there is a certain predictability and often tedious repetition within the sexual act itself – the location is usually the same, same house, same room, same bed，same person，same procedure. Then there is the need to keep the (totally artificial）nuclear family intact by ensuring dad does not sleep with anyone other than mum and vice versa。

How to improve sexual enjoyment for women given these culturally imposed restrictions？Well we can all learn something from the lama farmers of South America。Lama breeders became alarmed as they noticed fertility rates in their domestic herds were progressively dropping。 After numerous experiments failed they hit upon the solution of separating males from females and keeping them apart until the females were on-heat。This worked a treat。When the sex-starved males and the on-heat females were reunited their sexual need for each other seemed to know no bounds。

We all remember how great sex used to be with our partner before we started living together。Then every encounter was wonderfully lustful and emotionally fulfilling。But familiarity，especially sexual familiarity，definitely does breed contempt。So one has to use one’s imagination and also be prepared to be a little untraditional。Sleeping separately does not mean your relationship is a failure，especially if you both agree to do it in order to enhance your sex life – and besides, you get a better night’s sleep。

Timing sex to ovulation is also ideal。 Although women are technically on heat 24/7 there is an appreciable rise in sexual interest when she becomes fertile – we are different from most of the animal kingdom，but not that different。Given that women are generally inaccessible sexually during menstruation，and mixed with a sensible routine of voluntary abstention，reigniting the flame and rediscovering orgasms is entirely plausible。

There is one other ingredient that is absolutely critical。Foreplay。As far as women are concerned，extended foreplay is a must，whether mental or physical, sex without quality foreplay is highly unlikely to result in a female orgasm (although it should not be interpreted that foreplay for men is not vital also）。

Foreplay is not just preparation for physical sex – the largest sexual organ in the human body is the brain – it is a behavioral modification process that announces very clearly to the female that she is secure in her relationship，that her mate is prepared to spend time and effort ensuring she is happy and cared for。It is a strong confirmation of the pair bond，as is any female orgasm resulting from intercourse (and perhaps the reason men enjoy seeing their lover climax。）When it comes to satisfying sex for women, the golden rule is quality, not quantity.

Further reading:

http://www.sciencedirect.com/science/article/pii/S0003347211003435