Tag: sex

“Cheating gene” mouth swab test available

Posted in news by jenapincott on May 8, 2010


In BLONDES and in this post I write about the so-called “cheating gene.”

Not long ago, Hasse Walum, a handsome post-graduate at the Karolinska Institute in Sweden, decided to study the association between a particular gene for what is called a vasopressin receptor and relationship stability. He analyzed the responses of over 550 twins and their partners to questions, some of them intrusive, about their relationships: How often do you kiss your mate? “Have you ever regretted getting married/moving in?” “Have you discussed a divorce or separation with a close friend?” “Rate your degree of happiness in your relationship on a scale of 1-7.”

Walum then sampled the men’s DNA. Getting DNA from the men was simple. You don’t need blood to have access to another person’s genome, just saliva, which the men submitted in a mouth swab.

What Walum discovered was stunning. Focusing on one particular vasopressin receptor gene variant, allele 334, he found that the more copies of it a man had, the weaker his bond with his partner. Men who lacked the gene variant were generally happiest in their relationships — only 15 percent of them had a crisis. Men with one copy were slightly more likely to have marital problems. And men with two copies were, on average, twice as likely to have had a relationship crisis in the past year than men who didn’t have the variant — meaning that 34 percent of them, or one in three, were headed toward a break up. Their partners agreed. Women whose partners carried one or two copies of the allele 334 variant were generally less satisfied with their men, probably because they generally scored as less affectionate than other guys.

Walum also found that men with two copies of the variant were nearly twice as likely not to marry their partners and mothers of their children as men who had no copies of the variant. This suggests that there is something slightly different about the vasopressin receptors in the brains of men who struggle in their roles as partners and fathers. These men may have more difficulty bonding with other people, including their wives and kids.

I imagine that some of you are now scheming to get an allele 334 test for your man. Of the more than five hundred women who responded to my online poll on this topic, nearly 65 percent said they would test their man if given the option.

And now you can. Yes, you can order a saliva test for allele 334 of the AVPR1A gene for $99 from Genesis Biolabs. (I can’t vouch for the lab. I’m reporting for entertainment purposes.)

Ladies, there’s a caveat here, of course. Even if there’s a correlation between this particular gene variant and a man’s behavior, it doesn’t account for all men. Just as the “god gene” and “gay gene” are met with skepticism in the scientific community, so is the “cheating gene.” Even within Walum’s study, there were men with two allele 334 variants who were happy husbands and fathers, and there were men without the variant who were miserable in their relationships. The statistics apply to populations, not individuals, who are also influenced by a other factors — parental role models, partner choice, opportunity to cheat, past loves, age, life satisfaction, religion, hormone levels, and so on.

A two-allele man may become a number one husband under the right circumstances.

But it’s your call. Swab him and then decide?

A new theory on men’s penis shape?

Posted in news by jenapincott on April 27, 2010

Several months ago, I blogged about a new theory on why men love breasts. New theories pop up all the time, so it’s no surprise that there are new theories on male body parts, too. A recent issue of Archives of Sexual Behavior features an alternative explanation for the shape of the human penis.

As described in BLONDES, the prevailing theory on why the human penis has a distinctive head and corona (rounded projecting border) is that it can scoop out semen deposited in the vagina by a woman’s previous lovers, thus averting a pregnancy. This means the last lover, not the first, gets the head-start.

Not likely, says Dr. Edwin Bowman, in his letter to the editor.

Instead of scooping out other men’s semen, writes Bowman, the penile head and corona scoop out vaginal secretions. After collected, these fluids are then absorbed by the foreskin. The mucous membrane of the foreskin, it turns out, is like a sponge for the stuff.

Why would evolution select for men to absorb vaginal secretions?

Just as semen has “mind control properties,” so do vaginal fluids. When ovulating and most likely to conceive, these secretions contain neurohormones such as pitocin and vasopressin. The latter in particular has been associated with bonding and is thought to trigger protective behavior among males for their partners. Vasopressin, after all, is thought of as a male “love drug.” Flooded with bonding hormones, a guy may be more likely to stick around if he impregnates his partner.

Knowing this, will more men use condoms?

Why do women get physically aroused and not even know it?

Posted in news by jenapincott on February 7, 2010

Some women seem to get turned on by almost anything man-on-women action, man-on-man, woman-on-woman, animal-on-animal, and so on. This is what sex researchers find when studying sexual arousal. When female volunteers are asked to watch erotic movies while outfitted with a plethysmograph, an instrument for measuring blood flow to the vagina, they often get very hot and bothered “down there.” Problem is, when many of those same women are asked to report how aroused they actually feel “up there” they often say they’re not turned on at all. Sometimes they even say they’re repulsed.

So what’s going on? Do women even know what turns them on?

Such is the puzzle that has plagued sex researchers for decades. And it’s a topic clinical psychologist Meredith Chivers and her colleagues address in a recent study, a meta-analysis of 132 papers on the genital measures of sexual arousal.

Why don’t women’s genital and subjective responses always agree? Here are a few theories the researchers present:

Women’s genital responses are hidden from view and produce less prominent somatosensory cues. While men may get turned on by feeling themselves get erect, women do not. However, [studies have found that] even when women received feedback about their level of vaginal engorgement, correlations (between genital and subjective arousal) were low and statistically nonsignificant. [Being told we’re getting turned on doesn’t necessarily turn us on.]

Women may edit their self-report of feeling sexually aroused because of socially desirable responding. Positive affect directs attention to erotic stimuli, thereby increasing sexual response, whereas negative affect interferes in the processing of sexual cues, resulting in lower sexual response. Lower concordance among women may reflect their experience of negative affect while watching the
conventional, commercially available erotica that is primarily produced for men.

Interestingly, the authors suggest that genital response to sexual stimuli may be an evolved self-protection mechanism:

Female genital response is an automatic reflex that is elicited by sexual stimuli and produces vaginal lubrication, even if the woman does not subjectively feel sexually aroused… Female genital response entails increased genital vasocongestion, necessary for the production of vaginal lubrication, and can, in turn, reduce discomfort and the possibility of injury during vaginal penetration. Ancestral women who did not show an automatic vaginal response to sexual cues may have been more likely to experience injuries that resulted in illness, infertility, or even death subsequent to unexpected or unwanted vaginal penetration, and thus would be less likely to have passed on this trait to their offspring….Reports of women’s genital response and orgasm during sexual assaults suggests that genital responses do occur in women under conditions of sexual threat. That women can experience genital response during unwanted sex or when viewing depictions of sexual assault suggests that women’s vasocongestion response is automatically initiated by exposure to sexual stimuli, whether or not these stimuli are preferred, and without subjective appraisal of these stimuli as sexually arousing or desired.

During processing of sexual stimuli, brain areas associated with emotional inhibition are activated among women… Genital responses are not affected by involuntary inhibition involving the anterior cingulate cortex, but subjective responses are. [Incidentally, women’s anterior cingulate cortex is most active when we’re ovulating and attracted to macho, high-testosterone men. The ACC is activated when you’re in conflict about something. Is this also a self-protection mechanism warning us to proceed with caution?]

Bottom line: Physical arousal is no proof a woman is really turned on. To really get a woman hot and bothered, you have to start from the top.

Rechanneling sexual arousal?

Posted in news by jenapincott on August 10, 2009

0_d321_3d4c4b52_XLScientists know exactly how to mediate sexual attraction between mice. Introduce males to females, and the brain region known as the anterior cingulate cortex (ACC) is activated. A new study has found that he neurons in the ACC are “fed” by a fusion of glutamate when a mouse is sexually aroused. Shut down the ACC with a sly drug and the result is a sudden loss of sexual interest. The drug used in the study was muscimol, the major psychoactive ingredient in some mushrooms such as Altamaria, and in mice it reduced sexual attraction within ten minutes of injection and lasted for about a half hour.

This is interesting because human attraction is also mediated by the ACC (as I describe in a previous post and in BLONDES). Researchers speculate the the ACC is involved in feelings of pain and pleasure and the evaluation of risk and reward. ACC activation affects our emotional state, leading to sexual behavior.

Is it possible to shut down our ACC with a drug such as muscimol (or a different drug without psychoactive side effects), and would it also temporarily make us asexual?

Bear in mind that what works in mice might backfire in humans. We may find that desire can overpower an addled ACC — there’s more than way to turn us on. For instance, sexual arousal of sorts is known to occur in a muscimol-induced dream state — although it often translates into a sort of cosmic awe. Some people apparently can have sex on psychedelics (although most popular ones are psylocybin-based, not muscimol); many can not. (Annie Sprinkle says that when she takes mushrooms (psylocybin) she doesn’t want to make love in a traditional sense, but found they can “deepen a relationship/”). It’s out-of-body sex. It transcends sexual arousal.

To get a real sense of the complexity of human sexual arousal we’d need human subjects — but even if volunteers are willing, certain experiments are unlikely to fly with ethics boards. Which brings us back to muscimolized mice, who, unbeknownst to us, may also be experiencing a sort of transcendental erotic phantasmagoria.

But a mouse couldn’t describe it as Annie Sprinkle does:

[Sex on psychedelics] was not about bodies coming together for physical sex, but about circulating sexual energy, which was everywhere and available just for the asking. I could tap into it just by tuning in and saying “yes.” I realized that everything was sexual/ sensual–that even all my little cells were all having sex. Sex was both microscopic and enormous.

Do beauties inspire higher sperm counts?

Posted in news by jenapincott on July 24, 2009

HughHefner Not all orgasms are created equal. For instance, intercourse orgasms are known to trump masturbatory ones, as evidenced by the amount of dopamine and prolactin produced. For men, sexual excitement produces higher sperm counts. As I recount in BLONDES, men who felt jealous or threatened by the possibility of a cheating partner had higher sperm counts than men who did not. The same is also true of male porn-watchers masturbating to a threesome. When guys watched two men attending to one woman, they had higher sperm counts than when watching one-on-one sex.

Sperm competition is the reason, according to the notorious British biologists Baker & Bellis. Men produce more copious, higher quality semen in situations in which those sperm might compete with rival sperm from other males.

And now there’s more — speculation that beautiful women also inspire men to have better quality sperm.

Female beauty has been found to enhance male sperm quality in other species. The latest evidence comes from a study led by Oxford biologist Charlie Cornwallis on Gallus gallus, a species of bird. Cornwallis and his colleagues discovered that the comelier the chick — e.g., plump with an elaborate comb — the better the quality her partner’s sperm (more motile, higher velocity, with a higher sperm count). Interestingly, this was true of dominant males but not subordinate ones, who appeared to put everything they had into every copulation. From Cornwallis’ perspective, the most fit males invest their best loads in the most reproductively fit females.

No study has yet proven that the same is true in humans — it’s not exactly ethical to recruit a guy to have sex with both a beauty and a plain Jane and then compare the aftermath. A beauty bias that affects sperm count may be true only in a wildly polygamous species, which humans are not.

Even so, this theory applied to humans doesn’t sound so controversial if you think about it — after all, sperm counts in men are associated with sexual excitement. Beauty can spark frisson. Even more exciting to ponder is how in practice an alpha male would make a larger reproductive investment in the most desirable mate. How does a Hugh Hefner decide? And wouldn’t it be ironic if this were true?

Nocturnal orgasms — women have them too

Posted in news, Polls and Surveys by jenapincott on June 25, 2009

For the 40 percent of women who’ve had one, an orgasm in a dream is often more intense that one in real life. And it’s not just a dream — a nocturnal orgasm is a real physiological phenomenon. The dreamer awakens to the same pulsing sensations she’d have during an orgasm from masturbation or sex. Her heart rate surges, her breathing deepens, her vaginal blood flow increases. Her orgasm might even be so fierce that she cramps up as she transitions from dream to reality.

Why?

A few studies shed some light:

1. During REM, the relative pulse pressure in the vagina increases. This also happens to a man’s penis, resulting in nocturnal emissions and morning erections. The content of the dream doesn’t appear to affect genital pulse — after all, it increases every time you sleep — but the physical sensation may influence your dreams (no one knows for sure). At the same time, the parts of the brain that inhibit orgasm, particularity the prefrontal cortex and amygdala, are offline when you’re asleep. (Readers of BLONDES might recall that the left amygdala, associated with anxiety, and the prefrontal correct are quiet during orgasm.)

2. Female orgasm can result from brain activity alone — “no hands.” Evidence of this comes from the research of Beverley Whipple, who studied women who reach orgasm via “self-induced imagery” (i.e. fantasy) alone. Volunteers’ blood pressure, heart rate, pupil size, pain threshold, and so on increase as they reach climax, their hands nowhere near their genitals.

As speculated by Whipple ( see also her research on paralyzed women), a “hands-off” orgasm may channel the vagus nerve, which is like a livewire that extends from the brain to the cervix via the heart, lungs, and other organs. Not every orgasm strums it — but, like hitting the right chord, a vagus nerve climax is said to be richer and more fulfilling. Some women think they can even feel it surge through their bodies from their brainstems. (See previous blog about asphyxiophiliacs.) It’s interesting: Vagus nerve activity might be one reason why so many women say their nocturnal orgasms are so much stronger than their diurnal ones.

Only in their dreams….

Why do women say chocolate trumps sex?

Posted in news by jenapincott on January 29, 2009

chocolaterex_468x481Ask most people what they lust after and the likely answer is chocolate. Ravishing a candy bar or a cup of hot cocoa, chocoholics claim to have chocasms. Chocolate lust is so intense that informal surveys in Europe and the United States report that about half their female participants prefer chocolate to sex.

One good explanation for this is that chocolate consumption is so often compared to sexual consummation, or a precursor thereof. But here’s the rub: there’s no proof that chocolate will lift the libido. If it has any amorous properties, they’re limited and vary from person to person. As detailed in BLONDES, chocolate contains neurotransmitters that might have a minor effect on the brain, but the scant amount in chocolate is rapidly metabolized. Chocolate is also a minor stimulant due to a caffeine-like property, and it contains the anti-clotting agent flavanol. Yes, it may be good for your heart, but researchers found no difference in sexual arousal between women who eat three servings of daily and none at all.

So why do many women say they’d rather unwrap a candy bar than roll in the sheets? Chocolate never disappoints is a glib answer, but there is something to be said for reliable pick-me-ups. The addition of sugar and fat in chocolate bars can raise your serotonin and dopamine levels, which lift your mood and energy levels. The stuff hits the reward-and-addiction circuits of the brain in the way that sex and other rewarding experiences do.

But why are there more female than male chocoholics? One theory is that serotonin levels are low in premenstrual women, and chocolate is a sweet way to perk ourselves up. (In fact, women’s desire for chocolate does seem to follow menstrual patterns.) But if that were so, wouldn’t any carbohydrate do — why crave chocolate and not candy canes? The answer could be that chocolate is unique. It has an unrivaled texture, aroma, and mouth-feel. It’s silken, sinful, and indulgent. Aided and abetted by (the serotonin-enhancing) milk and butter, it’s also a tactile marvel — it literally melts to your touch. It’s rich, complex, and sensual.

Perhaps the proper question is not how chocolate compares to sex. Ask instead how your lovers could be more like chocolate.

POLL: Love blockers –would you take them?

Posted in news, Polls and Surveys by jenapincott on January 14, 2009


Is this the end of love as we know it — exasperating, unpredictable, uncontrollable, and full of rogue potential? Does the future offer sex without emotional mayhem? Fuss-free breakups?

“Love is dead.” “Anti-love drug may be ticket to bliss.” Such are today’s headlines trumpeting the research of neuroscientist Larry Young. Dr Young and his team at Yerkes Research Center are best known for their studies on the love lives of more-or-less monogamous prairie voles. (In BLONDES I describe their fascinating views on the genetic and hormonal basis of bonding and what it might mean for humans. On a related topic, check out my cheating gene post.) The first question inspired by this research is “Can a drug make you fall in love?” The flip side of this coin is just as rich: “Can a drug prevent you from falling in love?”

For now it’s all speculation, but many researchers, including Dr Young, believe the latter is possible. (Fewer care to speculate on the former. Given how difficult love is to define, it’s easier to say you can prevent it than invoke it.) The gist of the idea is that a drug could short-circuit the biochemical pathways that flood the “emotional bonding regions” of the brain with neurohormones such as oxytocin and vasopressin. Just as morning-after pills work by preventing fertilized eggs from implanting, so the “anti-love drug” — oxytocin or vasopressin blockers — would prevent emotional seeds from taking root. Female voles who are given anti-love drugs can mate with a male dozens of times and fail to exhibit any of their usual bonding tendencies, no matter how affectionate the males.

What good is an anti-love drug? The possibilities abound. A few nasal puffs and a woman may more easily have “sex like a man,” feeling pleasure but free of the morning-after anxiety of whether he’s “all that into her.” People in addictive, abusive relationships could just pick up and carry on. Couples may have open marriages without emotional messiness. There may be fewer midlife crises involving trophy wives and umbrella boys. Sex would be only sex. The anti-love drug could be a temporary fix of sanity.

But would you dare take it — even on a short-term basis? At risk of throwing the poll above, my vote is no. What sort of human beings would we be without a range and depth of emotional experience? The angst and anguish of lost love. The self-mending. Even the melancholic savor. What would we learn about ourselves without it? Even in the twenty-first century I’d say it’s better to love and lose than never to love at all.

Women’s scent has mind control properties

Posted in news by jenapincott on January 10, 2009

bxp68578I was shocked by the overwhelming response (nearly 60,000 views!) to my post, “Semen has mind control properties.” Many readers said they think it’s a fascinating idea — that there are proteins and/or hormones in semen that subtly affect a woman’s sexual behavior. But what “secret weapons” do women have to “control” men?

I have a few responses, which are detailed in my book.

1. Women are (generally) the choosier sex. From an evolutionary standpoint, we’re pickier about our sexual partners because we have more at stake in the event of a pregnancy. Everywhere around the world, even in the most egalitarian countries, women desire fewer lovers than men do. Although women make trade-offs depending on their circumstances, we’re more about quality (even for flings). This by default gives women a sort of upper hand.

Now the sexier stuff:

2. Chemicals released during sex affect men, too. When he orgasms, his body releases vasopressin, a neurohormone associated with bonding (and drowsiness — it’s one reason why men fall into contented postcoital slumbers). This means that sexual intimacy may make a guy more attached to his lover. How likely is this? Intriguingly, a lot may have to do with his particular vasopressin receptor genes.

3. A woman’s scent may have mind control properties. Guys tend to prefer a woman’s body odor around the time she’s most likely to conceive (as described in BLONDES). On a subconscious level, men have been found to behave differently around this time of a woman’s cycle. According to studies such as this one at UCLA, women report that their partners are more jealous, loving, possessive, and attentive when women have high levels of luteinzing hormone in their system, a sign of imminent ovulation. In the famous stripper study, johns were also much more generous — paying up to twice as much — when the strippers were fertile. Scientists speculate that men are unwittingly responding to estrogen-related properties in women’s sweat and other bodily fluids. Men, meanwhile, are oblivious to why they’re acting so servile.

Bottom line is that there are no doubt many hormonal signals that give either men or women the reproductive upper hand. We’re all either sperm-zombied or pussy-whipped — that’s what some readers have quipped. But a sweeter way of looking at it is that these neurohormones also help give rise to love and long-term attachment. Not to say that chemistry could or should ever define love, but it does help explain some bonds.

Santa makes people jump in the sack

Posted in news by jenapincott on December 23, 2008

santababy_000There’s upside in a down economy — if you’re in the condom business. According to an interview with the condom manufacturer Trojan , their sales peak is the week between Christmas and New Years. Come Santa season, everyone seems to jump in the sack. (Here’s further proof of the “Santa effect.”)

What is it about Christmas that revs up the sex drive? The increase in sexual activity at at the end of December harks back to Saturnalia, a pagan holiday when people feasted on boar flesh and indulged in a lot of prehibernatory sex. Disapproving early Christians coopted the sexfest and turned it into the celebration of Jesus’s birth. “Why either/or?” ask modern day revelers, and now many both celebrate the baby Jesus and also enjoy conceiving (or preventing the conception of) their own babies. It’s unsurprising that people have more sex during the weeklong holiday: we have time to relax, drink, and socialize more. And not everyone wears Trojans — the birthrate in the United States peaks in the summer and in September, nine months after the winter bacchanalia.

Even more interesting, there may be a biological reason why people’s sex lives heat up as the seasons cool down. In BLONDES I describe the connection between hormone levels and waning daylight hours in autumn. And we’re not alone: other animals in the northern hemisphere also have their rutting season in the late fall — including reindeer.

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