SEXY SCIENCE LESSONS

There's something to be said for the idea that sex should be a mystery. But the trouble with that is you can't possibly get the best out of something you don't understand. You wouldn't shop for the finest ingredients then take a wild guess at how to cook them. In the same way, having sex without understanding what's going on in your body means you're missing out. By gaining an insight into the science of sex you can ensure a major boost to your enjoyment. So here are all your questions answered – and remember, the best thing about this kind of science lesson is the practical test at the end.
1. “Why does he want sex so much more often than I do?”

Basically, because he's awash with the hormone testosterone and you're not. Women have it, but not nearly as much as men. Testosterone is largely responsible for lust, anger and increased physical strength. Ceren Altin, of online science magazine Kingdom Robertea, explains: “As you get older, the level of testosterone decreases in both sexes and causes a decrease in libido.”
On the upside, what women lack in testosterone they make up for in sensitivity. Women respond better to touch than men, whose testosterone levels mean their skin is thicker and thus less responsive.
Researchers are currently investigating the possibility of producing a testosterone-based pill for women, because women with greater levels of testosterone have a higher sex drive. Currently there are no female equivalents of Viagra that have been medically approved, although various sensitising creams that draw blood to the genitals do exist. Alternatively, some herbal pharmacists suggest small doses of damiana, which stimulates the urinary tract and thus feelings of sexual excitement, or herbal supplements such as ArginMax, which helps the body develop nitric oxide and leads to arousal.
2. “Why do women orgasm?”

This is a hot topic in sex circles because, unlike men, women don't need to orgasm to ensure conception. US anthropologist Donald Symons suggest women share men's basic neurological mechanisms, which is nature's way of simplifying the genetic human blueprint, In this way, the clitoris is simply an undeveloped version of the penis, serving no biological purpose – just as men have nipples but can't breastfeed.
Undeveloped it may be, but the clitoris is extremely sensitive. And although many women don't orgasm through intercourse, clitoral orgasms are much simpler to achieve (and many hours of fretting could be avoided if most women – and men – realised that). If he can rub your clitoris while inside you – the best position for this is you on top – you, too can come during intercourse, without worrying about where your G-spot is.

According to Dr Glen wilson, co-author of The Science of Love, “Impressive confirmation of Symons theory of female orgasm comes from the discovery that male hormones increase a woman's sexual responsiveness.”
If you are still pursuing the big O, Wilson's advice is not to give up. “Fingers haven't yet evolved for playing the piano,” he explains. “However, many of us have learned to do so, thereby giving ourselves – and other people - a great deal of pleasure. Likewise, many women who have not experienced an orgasm can learn the skill and their partners can be taught to assist.”
3. “What actually happens during an orgasm?”
Sex research pioneers Masters and Johnson tabulated 10,000 episodes of sexual activity in more than 600 women (and men). They found that the human sexual response cycle consists of four stages: excitement, plateau, orgasm and resolution. During orgasm men and women report very similar feelings. For men, direct genital stimulation usually causes an erection in seconds. Also, the testicles are pulled closer to the body, the scrotum tenses, muscles clench and blood pressure increases. For women, the excitement stage is characterised by the onset of vaginal lubrication, clitoral erection, changes in the size and shape of the labia, nipple erection and swelling of the breasts. At this stage, symptoms increase in intensity. Orgasm, for men, involves emission (when semen gathers in the upper part of the urethra, leading to a three-second sensation of “ejaculatory inevitability”, according to Masters and Johnson) and expulsion (four to five rhythmic contractions at the base of the penis, forcing semen out).
Orgasm in women involves rhythmic contractions of the uterus and the muscles round the vagina. Women normally experience three to 10 very strong contractions, also at 0.8 second intervals. In both sexes, oxytocin is released, which strengthens contractions.
Best of all, while he only gets one orgasm per session, you are ready to go again from standing start.
4. “Yes, OK, but how do I get one?”
If you've never experienced an orgasm you're not alone: it's a sad fact that three quarters of women don't orgasm through intercourse – but you can change your fortunes.
Firstly, you have to prepare your body for sex. The vaginal lubrication, clitoral erection, changes in the size and shape of the labia, nipple erection and swelling of the breasts are all the basic ingredients to get you to the finishing line. Unless all these changes happen, you're unlikely to come – so if he's bashing away and you're getting nowhere, he needs to pay more attention to your clitoris and breasts until you reach the plateau stage. Then, he needs to take a bit more time out from his side of things to make sure he's reaching all the right places.
Dr Barbara Keesling, author of The Good Girls Guide To Bad Girl Sex, says “Some intercourse positions are more likely to offer the stimulation a woman needs to have an orgasm.
“The one I recommend is the position in which the woman lies on her back with her legs in the air and knees bent and her partner kneels between her legs. This stimulates the pubococcygus (PC) muscle (also known as the pelvic floor muscle, which you use to hold back urine), the cervix and the G-spot and allows her partner to easily withdraw his penis to stimulate the clitoris.
“Some orgasms may include only PC muscle spasms and a mild, good feeling – others may be strong they cause your body to arch of the bed,” Now you know the theory behind it, it's a case of practise, pratise, practise.
5. “Can he tell if I fake an orgasm?”
Not necessarily, but some signs can be harder to emulate than others. As well as the flushing and screaming, real orgasm cause your toes to clench, so it you are faking it, don't forget to get your tootsies involved. Internally, the only certain physical changes are the contractions of your vagina – and they can easily be faked, as women have strong muscles in that area. In fact, doing so may be very worth while as it can encourage a real orgasm.
But instead of faking it, why not try to get into it. Make sure you allow yourself to relax; stress lowers your libido by inducing the hormone prolactin, which reduces sexual arousal. Pour yourself a glass of wine, have a massage and let your mind wander into the play zone.

6. “What's the most pleasurable time of the month to have the best sex?”
Women become more sexually promiscuous during the middle of their cycle, which is your body's way of encouraging you to get pregnant. The female fertility hormone, oestrogen, is released in greater quantities mid-cycle to prepare you for pregnancy. Also women who have regular sex have higher levels of oestrogen, making them more fertile (and more keen!).
As well as this oestrogen surge, there's another factor contributing to your increased sex drive mid-cycle – your sense of smell.
Scientists of the Research Group for Sexology at the University of Cantania, Italy, studied 60 women, aged 18 to 40, none of whom were taking the pill. Each was exposed to a range of common smells – aniseed, musk, clove, citrus and ammonia – at various times during a single reproductive cycle. The researchers found that a woman's sense of smell is strongly linked to sex drive and may give women the ability to detect pheromones in a man (sex chemicals that send subliminal messages to those around you), thus helping them find a sexual partner.
Backing this up, a University of Northumbria study conducted this year asked women to rate men's attractiveness from photos. When the experiment was repeated with the volunteers secretly exposed to male pheromones, all rated the men as more attractive.
7. “Why are some areas of my body more erogenous than others?”
Erogenous zones tend to be areas with the thinnest skin and the greatest concentration of nerve endings. They include the sides of the neck, breasts, inner arms and thighs and obviously genitals. The thinnest skin on the body, however, is on the eyelids.
Women may be more interested in having their erogenous zones explored than men are, as guys are already blessed with the ultimate in thin-skinned erogeny in the form of a penis. As for where's best, well, if it feels good, do it.
The ancient Greeks believed that the most erogenous part of the body was the philtrum – the indentation above the lip. Whatever area flips your switch, it's worth paying attention to it – stroking and licking erotic zones sends signals straight to the penis or clitoris.
Focusing on the erogenous zones is the essence of foreplay, but sex counsellor and author Susan Quilliam issues a word of caution. “Penetrative acts are the way men most easily get aroused and climax.” she states. So whereas 34 per cent of women think foreplay is more important than intercourse, only 14 per cent of men agree. Men value foreplay simply because it gives pleasure to women.” Make sure he knows how vital it is for your pleasure.
8. “Is 'not tonight, I've got a headache' a valid excuse for not having sex?”
No. In fact, sex can cure a headache faster than Nurofen. This is because of the dopamine produced by the body during sex. Christophe Maquestiaux, a neuroscience expert based at the California Institute of Technology, explains, “Scientists have determined that, at its maximum, the pain relief offered by dopamine release is as potent as a high dose of morphine, making you feel better and letting you forget your worries as long as the stimulus is present.” Dopamine is the chemical that floods the brain when cocaine is taken, deadening pain. So if you've got a headache, you know what to do...
9. “When I fell in love with my partner, I wanted sex all the time. Four years on, I can't be bothered more than once a fortnight – why is this?”
When you're first attracted to someone, the hormone phenyulethylamine (PEA, which is also found in tiny quantities of chocolate) increases feelings of infatuation. And it's joined by a cocktail of equally strong chemicals, including norephinephrine, which makes you energetic and attentive, and dopamine, which floods you with happiness and desire.
The bad news is that after four years of neurotransmitter bombardment, your responses dull. You lose your sensitivity to chemicals responsible for that furious sex drive that you had when you first fell in love. Instead, other endorphins – including the “mothering” oxytocin – prevail, keeping you together but not necessarily desperate to spend all your time in bed.
So, what can you do about it? Research shows that dangerous situations increase production of adrenalin and in turn boost sex drive, because the body, having just averted death, wants to procreate. In an experiment in 1974, US psychologists found that when volunteers crossed a rickety rope-bridge, they were far more likely than volunteers who'd done nothing dangerous to rate pictures of the opposite sex as “very attractive”. So, to rejuvenate your flagging sex life, take up dangerous sports together. Or failing that, just watch a scary movie.
10. “Is monogamy a realistic hope – or are we genetically hard-wired to sleep around?”
There may be little scientific truth in the old ditty, “Hogamous higamous, man is polygamous; higamous, hogamous, women is monogamous.” In fact, it's a far more equal world.
Sexual attraction is activated in the brain by a variety of endorphins, including phenyulethylamine (Pea). This in turn releases a chemical called vasopressin, also known as the monogamy hormone, as it urges a man to make sure his mate doesn't go off with anyone else. One plus is that it means he has to stick around, too.
Women also have a monogamy drug. During physical intimacy – touching, stroking and sex – women produe the hormone oxytocin. As well as engaging the mothering instinct, it also helps you bond with your partner. (Men respond less hormonally to touch, which is why cuddling is often less important to them).
However, this doesn't mean it's monogamy all the way. While men may have a biological urge to “spread their seed”, women are just as likely to keep their options open. Dr Robin Baker, author of Sperm Wars, claims that during ovulation women are programmed to seek out the best sperm to impregnate them, even if that means having sex with two men in the same day during their monthly window of fertility. But, girls, if you do take advantage of your naturally sexy times of the month, remember: that handsome stranger might not seem quite so appealing in a few days time.