Loving Your Body 2011
Chemical Love Flash, Bang, Bam!
Sweat Your Butt Off Yoga at a cool 105 degrees
Diamond Dilemma Buy your baby an ethicalûValentines bauble
The Love Truffle And other sweets for your Valentines sweetie
Sledgehammer Love They laughed when I picked up my big tool
Flash, Bang, Bam!
by Shannon Finnell
They say love is all about chemistry — turns out, screwing is all about chemistry, too (and biology and psychology and even math). Modern technology is making it possible to understand more about the science of sex, which is hard to flesh out, even in many well-studied areas. EW talked to some scientists and surveyed the studies to find out more about whats going on while youre getting it on.û
|Photo by Trask Bedortha|
hot, wet and ready
Conventional wisdom (i.e., sexism) holds that men become aroused visually while women are only excited by romantic notions. Thats why chicks hate porn, right? That particular cultural myth has been proven false.
Women get wet for mating bonobos. Actually, pretty much watching anyone having sex instigates womens genital arousal, which is calculated by sticking a light-up device in a womans vagina and detecting the alternating current from the pressure changes in her vessels. Men are slightly more picky: Their genitals only rouse when they see sexual activity involving their preferred gender.
Meredith Chivers, a researcher who conducted these experiments, wrote in 2005 that for women, being able to get slippery without love or even attraction "may be an evolved protective mechanism." This automatic lubrication can protect women from friction-induced injury even when sex isn't the most fantastic experience.
While genital arousal makes the world go round, sex doesnt start to get exciting without the brain. Psychological arousal is vital for sex that's actually good, and the women who watched the bonobos in Chivers study didnt report feeling at all turned on.û
The hormone oxytocin starts mediating emotions during foreplay, and thats one of the things that can make people feel good, according to Sarina Rodrigues, an OSU psychology professor who studies neuroendocrinology. An almond-sized region of the brain, the hypothalamus, creates oxytocin (along with other hormones), then sends it to the pituitary gland. When things get sexy, oxytocin starts emerging. "It's released with skin to skin contact, like spooning, massage, kissing," Rodrigues says.
Oxytocin also plays roles in different processes like birth and bonding related to that feeling of wellbeing. "It seems that oxytocin decreases how much your emotional centers activate, especially your fear centers," Rodrigues says. "It also calms your heart and decreases cardio responses to stress."
So why is it so important to tamp down on stress and distraction during sex? Cant we still get the evolutionary job done while updating a mental to-do list?
Nope. Two Dutch sexologists (best job title ever) found that for both men and women, distractions are a total downer (and softener). Jacques van Lankveld directed a woman to distract men who were looking at breasts by reading pairs of random digits through a loudspeaker. Their penises shrunk, but they still felt horny.
Van Lankveld and Elske Salmink repeated the experiment for women with and without sexual problems, and found that distracted women reported significantly less sexual satisfaction after the test was over, even if they were both psychologically and physically aroused during the experiment. So, even if the women in the study got aroused, distraction kept them from reaping the post-coital benefits.
Oxytocin fosters a sense of well being, which allows the otherwise tense to get it on. Rodrigues explains that scientists have interpreted a lot about which hormones trigger which sexual feelings. "There are a lot of different hormones involved," she says. "We have dopamine, that rush we get with romance. Oxytocin is more of that kind of devotion feeling, and also that relaxation-fuzzy feeling we have."
Whatever does the trick, a common physiological factor in arousal is blood flow. Erections occur when blood starts flowing into the penis. If you could look at a cross-section of a penis, it would look like a clown wearing Aviators: a round mouth (the urethra) with large, adjacent eyes above it (the corpora cavernosa). The corpora cavernosa are spongy structures that fill up with blood, which makes the penis hard and erect.
Women have a similar blood flow theme in the clitoris, though it typically isnt a big visual show. Thats because most of the engorgement happens inside of the body, where about nine-tenths of the clitoris resides. Scientists confirmed this by getting women aroused inside MRI machines.
plateau-ver and over
Like any dependable scientific model, sexologists have a classic model of the sexual response cycle, which William Masters & Virginia Johnson introduced in 1966. The human sexual response cycle dictates that after the initial phase of arousal, a sexual plateau follows.û
The plateau is marked by increased heart rate and elevation of respiration. In men, the urethral sphincter (yes, you have one), the circular muscle group that controls urine flow, blocks pee from mixing with sperm. Both men and women become sensitive to touches around the anal sphincter, which for most people now contracts at the touch. (This is the sphincter people giggle about, but you have more than 50 sphincters including the microscopic ones.)
As the cycle progresses, women produce more vaginal fluid and men produce pre-ejaculatory fluid. They are fairly similar, based mostly on sweat and some small organic molecules. Contrary to popular belief, pre-ejaculatory fluid, more famous as pre-cum, contains little to no semen (but stay safe, kids).
This plateau is when some people get loud, encouraging their partner, making nondescript sexy noises or shouting curse words. While these vocalizations have traditionally been considered involuntary, new evidence strongly suggests thats not true. Last year in England, researchers studying women having sex with men found that in women, these vocalizations arent correlated with their own orgasm, but with the sexual response of their partner. And 80 percent of women reported being entirely aware of it; they made noise because they liked making their partners feel good.
The study suggests that because (heterosexual) mens sexual response course is propelled forward by female vocalizations, women have some evolutionary protection. Vocalizations can help women become inseminated or help them end sex if theyre no longer enjoying it or just want to do something else.
Tierney Lorenz of the Sexual Psychophysiology Lab at University of Texas at Austin says that much of the belief that sexual vocalizations are involuntary relates to studies of animal sexual vocalizations. "There are studies of monkeys," Lorenz says, "in which their vocalizations are much more stereotyped and standard across species, more reflexive. Exactly the same sound is made in exactly the same way. Humans have more variation."
The musculature that controls human vocal cords is voluntary musculature, and Lorenz says "to a certain extent it would have to be voluntary control." Still, she says that some vocalizations might not feel voluntary. "It's as if you're in a passionate argument," she says. "It's as voluntary as if someone smacked you in the face and you raised your hand to defend yourself."
Orgasm is tougher to define than one might think. In both sexes, the norepinephrine spikes in the brain; one measure of male norepinephrine found levels up to 12 times higher than levels outside of sexual activity. Cindy Meston of the UT Austin Sexual Psychology Lab found that it promotes orgasm. But due to the anatomical differences, orgasms in men and women are very, very different.
A guys orgasm is easier to explain. Its also the shorter and usually non-repeatable version. The average male orgasm lasts for a few seconds, long enough for sperm to spew. However, ejaculation and orgasm are not synonymous, and sometimes some men experience dry, ejaculation-free orgasms.
Researchers have discovered that mens orgasms are most frequently triggered by firm, repetitive strokes of the penis, which cause the muscles of the pelvic floor to contract. Yet, many men and women can achieve orgasm from anal sex. In men, stimulation of the prostate, the walnut-sized gland wedged amongst the rectum, penis and bladder is what makes it happen; in women its pressure and friction on clitoral tissue thats inside the pelvis.
While scientists spent decades arguing about womens ability to orgasm, women were getting off two different ways: by clitoral and vaginal orgasms.
ûMost women are able to experience clitoral orgasm by masturbation, partner manual stimulation or through the friction of rubbing against a partners vulva or pubic bone. The fact that these types of orgasms result from different physical stimuli (inside and outside) has been known since Sigmund Freud, aka Clitoral Enemy Number One, pronounced that clitoral orgasms were infantile and adult female orgasms should center around the vagina (and therefore the penis).
Fewer women, only about 30 percent, experience vaginal or øg-spot" orgasms. The g-spot is an area on the inner front of the vagina that in some women is very sensitive and causes orgasm, but in others its not, and clitoral stimulation before/during/after sex is their pleasure prompt.û
Women who climax vaginally generally report that its all about the angles when they have sex with men. If woman on top is one of the best ways to make it happen, then missionary is the worst. Thats because a woman on top has more control and can adjust the frequency of penetration, as well as the angle of her body, so that the penis pushes, right th-, that's it — yeah!
viva la resolution
Post coitus, the pituitary gland releases more oxytocin (at least in men, more studies are pending in women), leaving people less stressed and with a sense of well being. In people who experience a "refractory period," sexual processes are shut down and additional sexual activity might be painful. More men than women experience the refractory period, but those of both sexes who dont can sometimes experience multiple orgasms.û
Blood pressure and respiration drop almost immediately in the resolution phase, and physiology goes back to normal € or almost normal. Unless the rest of a relationship or non-relationship BRING's with it unhealthy baggage, sex has significant positive benefits. The elevation of heart rate is good for cardiovascular health, and sex releases a lot of stress. One Australian study found that men who ejaculate more frequently in their 20s have lower rates of prostate cancer later in life.
If advances in the science of sex keep giving us more good news, soon everybody will be doing it!û û û û û û û û