The science of (mostly) human sex

‘Satyress with a Putto’ by Giovanni Battista Tiepolo

It’s hard to believe the results of a questionnaire in which 34% of the respondents say they’ve had sex with animals. This study was done in Brazil, which leads one to wonder how much they have in common with Colombia, where it’s not uncommon for men to have had sex with donkeys (if this Vice video is to be believed — WARNING: man-on-donkey action in the last two minutes of the linked video).

Why does semen glow in the dark?” And could that trait somehow be used to stop sperm theft? “Mr. Pressil’s former girlfriend and domestic partner, Ms. Anetria Burnett, supposedly secreted Mr. Pressil’s used condoms to a fertility clinic, which then used Mr. Pressil’s sperm to inseminate Ms. Burnett.  Ms. Burnett subsequently gave birth to twins. Mr. Pressil took a DNA test that proved he was the father and then began paying child support of $800 per month.”

“Female ejaculation and squirting/gushing are two different phenomena. The organs and the mechanisms that produce them are bona fide different. The real female ejaculation is the release of a very scanty, thick, and whitish fluid from the female prostate, while the squirting is the expulsion of a diluted fluid from the urinary bladder.”

Controversial in that the thesis of [The Technology of Orgasm] has been almost universally accepted and embraced by the mainstream press and the sex toy industry, while at the same time being quite seriously critiqued by historians of sexuality. In her book Maines contends that the vibrator was regularly used by doctors to treat “hysteria” which they had previously been treating by manually stimulating women to orgasm.”

From the new movie “Hysteria” (based on Maines’ theory)

“In two experiments, we showed that memory in women is sensitive to male voice pitch, a sexually dimorphic cue important for mate choice because it not only serves as an indicator of genetic quality, but may also signal behavioural traits undesirable in a long-term partner.”

“John L. Locke … argues that men and women have radically different ways of speaking … because they have radically different evolutionary needs. Men, he argues, use antagonistic speech, or “duels,” to show off their strength and prove themselves to women. Women, meanwhile, use quieter speech patterns to bond with each other.

“Even girls who are having a one-night-stand want to cuddle and kiss and become anxious about what their male partner is thinking of them, or whether they still find them attractive. On the other hand, the interviewed men largely declared that they usually wanted to eat, urinate or sleep after sex.” Here’s a pdf of the cited paper, “Variation in Reproductive Strategies Influences Post-Coital Experiences With Partners”.

“”When a woman has an orgasm,” he explains, “the pH of her reproductive tract shifts in a way that favors sperm that enter her at that point.” Why is this so important? Sperm competition. In prehistoric times, according to Ryan, women had “multiple lovers at any given ovulatory cycle, even in any given sexual event”.

“[Terri Conley] disagrees with the various forms of scientific evidence indicating that men have a stronger, biologically-evolved sex drive than women. Her alternative explanation …  is that both men and women are motivated by an equally strong interest in the physical pleasures of sex. It is just that men anticipate that casual sex will usually be pleasurable, while women do not anticipate that casual sex will be physically pleasurable unless a number of conditions are met.” A critique.

“Studies have confirmed that women are overwhelmingly more likely to cheat on their partner during the two or three days of ovulation. … Here’s the rub: The idea of what constitutes “the best man” also changes during that time. The good news is that you’re pretty safe for about 27 days of most months. To be fair, if her body chemistry is artificially altered by birth control pills, this instinct may be tempered.

“In lab studies, women who are in fertile stages of their cycle are more likely to go for men who look healthy, self-confident, and masculine, which tend to be markers for good genes, but also for infidelity. … Women on the pill do indeed select men who look like they will be more reliable and steady. But outside the lab …. the team found that women who had met their partners while on the pill reported less sexual satisfaction but greater general satisfaction than women who had been off the pill. In other words, their partners were good fathers and good providers, but not necessarily on fire between the sheets.”

“Swami et al (2007) looked at WHR [waist-to-hip ratio] preferences among males in Spain, Portugal, and the UK.In all three countries BMI, not WHR, accounted for the most variance in perceived attractiveness. … This paper also has a great summary of methodological issues with prior WHR studies (e.g., the use of two dimensional line drawing, failing to control for BMI). Cornelissen et al (2009) looked at patterns of British male gaze fixation during attractiveness judgments of pictures of women. Men tended to look at the upper abdomen and face, not the hip or pelvic area.”

Sophia

“Each additional sexual partner increased the odds of infidelity by 7% while increasing years of education seem to decrease the risk by 10%. Very roughly speaking each addition partner negates the benefit of a year of education with regard to infidelity risk.

“Paternal grandmothers will therefore share more genes overall with granddaughters than with grandsons (the authors calculate an overall genetic relatedness of 31% with granddaughters but only 23% with grandsons). … The results of this study matched the predictions beautifully. In all seven populations grandsons survived better in the presence of maternal rather than paternal grandmothers (p = 0.0081) while granddaughters survived better in six of the seven populations when they received assistance from paternal instead of maternal grandmothers (p = 0.0046).”

“A kiss puts two people in very close proximity. Our sense of smell allows us to pick up subconscious clues about the other person’s DNA or reproductive status. Biologist Claus Wedekind found that women are most attracted to the scent of men who have a very different genetic code for their immune system in a region of DNA known as the major histocompatibility complex. Pairing off with a male who has a different set of genes for immunity can lead to children that will have a higher level of genetic diversity, making them healthier and more likely to survive.

We investigated salivary testosterone levels in men watching (n = 26) versus participating (n = 18) in sexual activity at a large U.S. sex club. Subjects averaged 40 years of age and participated between 11:00 pm and 2:10 am. Consistent with expectations, results revealed that testosterone levels increased 36% among men during a visit to the sex club, with the magnitude of testosterone change significantly greater among participants (72%) compared with observers (11%). Contrary to expectation, men’s testosterone changes were unrelated to their age.”

“Both men and women become more religious when seeing same sex competitors. We discuss several possible explanations for these effects. Most broadly, the findings contribute to an emerging literature on how cultural phenomena such as religiosity respond to ecological cues in potentially functional ways.”

“Assuming that these studies are correct (more on that in a minute), and that sex is good for your health, then the obvious next question would be, how should you arrange your sex life so as to maximize the health benefits?

“According to a case report from cardiologists Yarlioglues et al, a married couple deliberately ate some mad honey “for reasons of sexual performance”. … The toxin in mad honey is gryanotoxin. It acts by potentiating the opening of sodium channels, which are found both in the heart and the brain. This may be why it produces a combination of cardiovascular and psychoactive effects.”

Dancer Lisbeth Gruwez, choreographer Jan Fabre:

Concerned clerics, Swedish sex changes and more MRI sex

Observational study of ‘Bicyclist’s Vulva’

Norwegian sex priest suspended for his book on sex in the Bible, in which he wrote that it “reeks of horniness, lust and pleasure, and is an endlessly rich tale of sex that can stimulate people’s own sex lives.”

The strange, sad tale of the overstimulated Rector of Stiffkey, a “prostitutes’ padre” who tried to “save” wayward young women and who was killed by a lion

Thoughts of death led both men and women to say that they’d be more likely than controls to go ahead with the one-night stand, thus showing how a subtle change in sexual symbolism can alter the relationship between morbid thoughts and sexual desire.

“Two studies, including an ecologically valid study of online dating advertisements, provided evidence for men’s production and women’s evaluation of humor in romantic contexts. A third study revealed that women’s evaluations of potential mates’ humor are predictive of their romantic interest. Moreover, this article shows that preferences for and perceptions of humor are associated with preferences for and perceptions of intelligence and warmth.

Inclusive fitness and kin selection in an account of homosexuality’s survival value

The intelligent homosexual’s guide to natural selection

Just How Naughty was Berlin? The Geography of Prostitution and Female Sexuality in Curt Moreck’s Erotic Travel Guide

Anita Berber

Anne Tamar-Mattis argues that ‘intersex’ should be kept out of the DSM, which leads her to oppose expanding the concept of gender identity disorder.

In Sweden, opting for a sex change entails consenting to be sterilized, since “if a woman becomes a man, she should not be able to become pregnant as a woman.” Some are trying to change this law.

A stats professor has a “learning experience” occasioned by a transvestite cardinal (a bird, not a cleric).

While writing about The Story of O, Susan Sontag “compared the ratio of first-rate pornography to trashy books within the genre to “another somewhat shady subgenre with a few first-rate books to its credit, science fiction.” She also maintained that like science fiction, pornography was aimed at “disorientation, at psychic dislocation.””

From Just Jaeckin's film version of The Story of O

Naomi Wolf: “We now know that porn delivers rewards to the male brain in the form of a short-term dopamine boost, which, for an hour or two afterwards, lifts men’s mood and makes them feel good in general. The neural circuitry is identical to that for other addictive triggers, such as gambling or cocaine.” NOTE ADDED (July4): See the refutation at Mind Hacks.

Another orgasm in an MRI: “”This kind of research is incredibly useful,” says Heiman. “Orgasm is tied into the brain’s reward system and likely other important systems as well. There is much we can learn about the brain, about sensation, about how pleasure works and probably much more from this one physical response.”"

One interesting ability that Kamisaruk found … is that some women … were able to “think themselves” to orgasm. Without using any external stimulation, women closed their eyes and, using only sometimes erotic imagery but just as commonly very random and abstract thought processes, achieved an orgasm that was indistinguishable from orgasms achieved through self-stimulation.

Scicurious on rat studies that clarify how antidepressants interfere with ejaculation

Annie Sprinkle likes Chester Brown’s comic-strip memoir of being a john

Sacred prostitutes, sexy books and why sex is worth it

Charlotte Rampling

Another excellent treasure trove of Veruschka pics. An older Veruschka: “My eyes carry more than happiness.

Western Sexual Mysticism: “The vast range of possibilities for hidden, erotic mysticism demand a closer look.”

Sex in the Dionysian mysteries, and sex in the Orphic mysteries

From a journal on endocrinology and metabolism, “Baubo: a Case of Ambiguous Genitalia in the Eleusinian Mysteries

Sacred prostitution in Sir James Frazer’s Golden Bough

Sacred prostitution and Aphrodite

More about sacred prostitution, and still more

Michael Coogan on “God and Sex”

Sex and the Renaissance Nun: Why Venetian Nunneries Were Once Hotbeds of Passion

Dr. Debby Herbenick’s research interests range “from examining attitudes toward vibrator use to investigating the relationship between sexual lubricant and pleasure.”

The Veruschka segment from Blowup:

Rhesus Macaques “pay” for monkey porn (pdf)

Sex differences in relative foot length and perceived attractiveness of female feet

While outbreaks of koro (a culture-specific syndrome involving belief that the genitals are shrinking and retreating into the body) are most common in China and other parts of south-east Asia, sporadic cases have also been reported in other countries such as Thailand, India, and even western nations such as Canada.

Hooters opens in Japan

Two kinds of Persistent Genital Arousal Disorder

This mind trick – called the Belladonna effect – is helping the team’s research into attractiveness. Large pupils is [sic] a known signal of physiological arousal, say the authors, so they predicted that making the pupils seem dilated would make a face appear more attractive.

From almost five years ago, Susie Bright on Playboy‘s list of the 25 sexiest books. Adam Ross recommends James Salter’s A Sport and a Pastime.

Laura Miller against the Bad Sex in Fiction Award

Charlotte Rampling (1974)

In this review, we summarize neural regulation of sexual function and neurological causes of sexual dysfunction in women.

Dr Abecassis performs a “hymenoplasty” as it’s called, at least two to three times a week. Re-connecting the tissue of the hymen takes about 30 minutes under local anaesthetic. … With Chinese manufacturers leading the way, there are now non-surgical options on the market as well. One website sells artificial hymens for just £20 (23 euros). The Chinese hymen is made of elastic and filled with fake blood.

When it comes to the age at which boys and girls first have sex, boys are far more influenced by what their peers are doing and by the number of available sex partners than are girls.

Several standard sex differences replicated across cultures, including women’s greater valuation of social status and men’s greater valuation of physical attractiveness.

Hypothesis: “Sexual frequency would moderate the association between neuroticism and relationship satisfaction.

Sex costs much time and energy. Is it worth it?

Alla Nazimova

Additionally, the mating dance is another cost of sex. Individuals expend time and energy seeking out mates, and may have to compete and display for the attention of all. Why bother?

Men, they’ve found, are less likely to continue a relationship with an unfaithful partner who’s had a heterosexual affair, as opposed to a homosexual affair. For women, it’s the other way around – they’re more troubled by their male partner going off with another man.

Some historians have proclaimed that America’s first gay president was really … the now-obscure James Buchanan. (He was the 15th president, serving from 1857 to 1861). Buchanan is the only bachelor to ever have held America’s top office, and his private life raised many eyebrows while he was alive.

In Search of Looks, Status, or Something Else? Partner Preferences Among Butch and Femme Lesbians and Heterosexual Men and Women“: “Previous research posited that butch lesbians are physiologically similar to heterosexual men, and by implication, femme lesbians physiologically resemble heterosexual women. The current study sought to compare partner preferences among butch and femme lesbians, as well as heterosexual women and men.”

Schéhérazade, Sir Henry Head and the Ladybirds

Cover for an LP by Scheherazade

I wish I knew what artist made this cool cover for a recording by a Japanese band called Scheherazade. I hit upon it while looking for images of the ballet Scheherazade, based on Rimsky-Korsakov’s music. The choreographer was Michel Fokine. The ballet’s first performance starred Ida Rubinstein and Vaslav Nijinsky.

Findings from the National Survey of Sexual Health and Behavior (a 140-page pdf)

There has been a transition for women in direction towards a stereotypically ‘male’ personality profile, but not at the expense of traditionally socially important female traits. Comparisons in psychological profile subscales showed an increase in dominance, exhibition, aggression and achievement.

Using … data from a high-fertility polygynous human population of Senegal, we first show that extraversion, a personality dimension predicting men’s mating behavior in this population, is associated with inter-individual differences in testosterone profiles, with men in the top quartile of extraversion distribution having 29% higher testosterone levels.

This study conducts an exploratory investigation of various post-coital behaviors that the authors propose may reflect the divergent adaptive reproductive strategies of each sex as understood from an evolutionary perspective.

What the presence of attractive young women can do to men

The scientific case for masturbation — 4 theories about its adaptive function

The best cover for a Scheherazade LP or cd, c. 1963.

A recent study suggests that daily masturbation and ejaculation can reduce the amount of accumulated DNA damage in sperm by 12%.  Therefore wasting sperm into a sock can actually improve the mobility of sperm and increase fertility.Here’s the study

Some history of masturbation: “Freud famously concluded a 1912 symposium on masturbation for the Psychoanalytical Society in Vienna by saying, ‘I think the time has come to break off. For we are all agreed on one thing–that the subject of masturbation is quite inexhaustible.’

Mind Hacks posted on erotic asphyxia. Here’s a review of the literature on autoerotic deaths between 1954 and 2004. Here’s a pdf of the first paper that I could find on this topic (in the British Medical Journal, 1960). After a gruesome description of the circumstances in which four men had died, the authors venture a Freudian hypothesis — somehow, the men wrapped themselves in plastic in order to simulate a return to the womb. (!) Then the authors make a more sensible claim: “A much less elegant and more superficial explanation is that these people were trying to achieve some undifferentiated thrill or excitement from partial suffocation or anoxia. This factor may have existed but it does not explain the transvestism, sexual arousal, or complete enclosure of the body. It is an interesting reflection that the sexual impulse in man is so protean in its manifestations that a technical advance resulting in a new packaging material can result in a new perverse manifestation.”

Here are some more recent (but equally sad) cases involving less typical autoerotic causes of death: “These modalities include ligature around the thorax or abdomen, plastic bags covering the face, electrical current, inhalation of a toxic gas or chemicals, or partial or total submersion, known as aquaerotic asphyxiation. This study highlights 11 cases of atypical autoerotic death, including asphyxia with a plastic bag, electrocution, and inhalation of butane and nitrous oxide (N2O).” Two more atypical cases: “We here report the case of a 34-year-old man who died due to asphyxia, secondary to body wrapping in the largest and most complex plastic bag ever involved in a published case of autoerotic death“; and “Unusual death of a 24-year-old man, involving propane inhalation and plastic bag suffocation, is described.

Back to a less depressing topic: You get a sense of the erotic nature of Scheherazade from this review of a perfomance by Anna Kisselgoff in the NY Times (Jan. 18, 1981). Kisselgoff summarizes part of the narrative as follows: “The wives bribe the chief eunuch to release the slaves who spring out to make love to the women. The leader of the orgy is Zobeide’s ‘golden slave’ …. It is common to think of ‘Scheherazade,’ with its frank acknowledgement of sexual passions, as an early expression of Freud’s century. To most Anglo-Saxon audiences at the time, it was inconceivable that a powerful queen would bother with a black slave. Russians brought up on tales of Tartar harems and white princesses had no trouble with the idea.” Here’s Yvonne de Carlo as she appeared in a 1947 movie called Song of Scheherazade.

Yvonne de Carlo in Song of Scheherazade (1947)

Based on the results of my study, there is a percentage of women (just over 30 percent) who feel powerful when performing fellatio. Apparently some women find it empowering and believe that it can wield a lot of power.

Sir Henry Head’s self-experimentation: “We then discovered that the glans penis responded to cutaneous stimuli in that peculiar manner with which we were already familiar from our study of the first stage of recovery after nerve division. … When … [the tip] was dipped into water at 40° C, no sensation of heat was produced, but [Head] experienced an unusually disagreeable sensation of pain. … But, as soon as the water covered the corona without reaching the foreskin, both cold and pain disappeared, giving place to an exquisitely pleasant sensation of heat.

For women not using hormonal birth control, it would appear that some information regarding female fertility appears to be encoded in gait.

Women with higher estradiol levels in the peri-ovulatory and luteal phase of the menstrual cycle were correlated with higher senses of desirability and a lower relationship commitment in women.” But SciCurious has objections.

Yvonne de Carlo in her most famous role as Lily Munster

In a study of 443 women, a pair of British researchers discovered that women were more likely to make impulsive purchases during the weeks between ovulation and menstruation, known as the luteal phase of the menstrual cycle.Here’s the study

Now let’s look a little deeper into the action of those neurotransmitters [dopamine and oxytocin] and how we can manipulate their action to extend the neurological orgasm for as long as possible.

A device for accurate breast volume measurements

William Saletan on anal sex

Angus McLaren, an academic explorer of the history of sexuality

A woman’s race/ethnicity and socioeconomic status impact whether health care providers recommend one of the most highly effective forms of contraception.

On Carl Djerassi, inventor of the pill

Vogue‘s first celebrity models

Alexander Lee’s ‘Short History of Desire

A list of abortions in literature

More about the trial of Lady Chatterley’s Lover

Depicting the harem as a home rather than as a sexual prison, books written by women from the progressive elite of late Ottoman society challenged the prevailing stereotype of harem women as ignorant, indolent odalisques whiling away their days awaiting their lord and master.

Ida Rubinstein in Scheherazade (1910) .jpeg by M. Evans & Theatrex

Male bonobos need their mommies to help them hook up with female bonobos

The male [chimpanzee] will pluck a leaf, or a set of leaves, and sit so the female can see him. He spreads his legs so the female sees the erection, and he tears the leaf bit by bit … dropping the pieces as he detaches them. Sometimes he’ll do half a dozen leaves until she notices. … [S]he sees the erection and puts two and two together, and if she’s interested, she’ll typically approach and present her back side, and then they’ll mate.

Exposure to a chemical found in food packaging and other plastics, BPA, can reduce the quality of men’s semenMore here

A non-stick coating for a substance found in semen dramatically lowers the rate of infection of immune cells by HIV

Female boa constrictors can reproduce without mating: “Large litters of all-female babies produced by the “super mom” boa constrictor show absolutely no male influence — no genetic fingerprint that a male was involved in the reproductive process.

But there is an interesting property of sea squirt pornography and local oceanography that may have consequences in the debates surrounding marine reserve design.

The Ladybirds: the world’s first and only all-girl topless band‘; more here.

Ladies in red, scary mothers, more sex cannibals and cabaret

When a lady wears red it prompts men to ask her more intimate questions and to sit closer to her.”

A percentage-point increase in the male-to-female ratio of a man’s graduation class led to a percentage-point increase in his likelihood of dying before the age of 65.”

Following all three election cycles, individuals located in states voting for the winning political party tended to search for pornography keywords relatively more often than individuals residing in states voting for the losing political party.”

A review of porn.com, an edited collection that examines porn as a driving force behind tech (esp. internet) innovations

The Old Pornographers: Richard Nash and Mike Edison on Banned Books

Fifty of those women … were randomly chosen to receive a placebo instead of a drug treatment for low sexual arousal. … The findings … show that on average, one in three of the women who took a placebo showed an overall improvement.”

Bayer’s new vaginal atrophy drug

A skeptical challenge of the notion of a porn-addicted brain

A skeptical challenge directed at recent waist-to-hip ratio research

Twiggy

A neat post about Twiggy, the too-thin, not-very-curvaceous 1960′s super-model

According to the researchers, reduced contraceptive use is most likely the result of a decade of abstinence-only sex education.”

Psychologists at Temple University find “no evidence that the initiation of sexual intercourse is hastened by exposure to sexy media.”

Lindsay Beyerstein rounds up some sex ed links and takes a recent study to show that “nearly half of teenagers are already having sex, and many others are doing their best to get in on the action. It’s hard to imagine a more perfect audience for comprehensive sex ed.”

Simon Baron-Cohen wrote of the autistic mind as an “extreme male brain,” and now Mark Brosnan et al ask, “Can an ‘Extreme Female Brain’ be characterised in terms of psychosis?”

These researchers went looking for male-female brain differences but found none in the ‘resting’ state, using fMRI

Canada tosses most of its laws restricting prostitution: “Judge Himel found that laws set up to protect prostitutes actually endanger their safety, forcing them to furtively engage in hasty transactions conducted in shady locations.”

The well-known eastern Munich bordello told Bavarian daily tz on Thursday that taxi drivers are paid up to €120 for every ‘John’ they bring to their rivals during the annual autumn beer festival, when hundreds of thousands of visitors are in town for a good time.”

Matt Ridley on hard-wired sex differences: “In virtually every mammal and nearly all birds, males are more aggressive, females more nurturing. It is a distinction that goes right back to active sperm competing for stationary eggs. … Wombs are worth fighting over—and granting to favored applicants only.”

Females produce only a few, large gametes while males produce a greater number of small gametes. Because females invest more, and because their productivity is not usually limited by the availability of male gametes, females should be the choosy sex. … There are only a few examples of organisms that have reversed the usual relationship, and the [seahorses and pipefish] are one such group.”

Jacobus Boomsma … has argued that strict monogamous behavior, such as an ant queen mating for life, spurred the evolution of cooperative breeding in some social insects. Monogamy helps fulfill Hamilton’s conditions, because all siblings are equally related to each other and to each parent. Promiscuity, on the other hand, leads to many half-siblings and lowers the relatedness of individuals in a group.”

We hypothesized that men’s relationship satisfaction and investment would predict interest in their partner’s copulatory orgasm, and that sperm competition risk would moderate the association between relationship satisfaction and interest in partner’s copulatory orgasm.”

The 2011 German farm-girl calendar is out

This study clarifies the adaptive significance of infertile sperm castes, which has remained elusive in Drosophila. … We suggest that spermicide and male countermeasures against it are more common than is appreciated and discuss how spermicide could drive the evolution of several key male traits, including sperm size and number.”

By varying the adult sex ratio of populations of the Indian meal moth … we altered the frequency of male and female copulations, and thus the level of sperm competition experienced by males. As predicted by theory, males evolving under higher levels of sperm competition increased investment in sperm production and differed in their sperm allocation patterns across matings.”

We assess this key assumption in seed beetles where genital spines in males physically injure females. We demonstrate that male spine length is positively correlated with harm to females during mating but also that males with longer spines are more successful in sperm competition.”

Otto Dix's painting of Anita Berber

On sexual cannibalism in black widows, red-back spiders, etc.: “Why not eat him; he’s not much use later anyway. Mating success is so variable among males, there’s no guarantee that living another day will pay off for him.  Most males fail to mate at all and some research suggests that males become functionally sterile after mating. So, why not?

Penis captivus describes an event that occurs in rare instances during heterosexual intercourse when the muscles in the vagina clamp down on the penis much more firmly than usual (a form of vaginismus), making it impossible for the penis to withdraw from the vagina.”

Information from species in which females remain in their natal group … shows the importance of kin support, especially from mothers, on the reproductive success of their daughters. Therefore, one might expect a similar effect on sons in species in which males remain in their natal group like bonobos.”

Bare naked 1960′s psychotherapy: “Perhaps most notable was an exercise called “crotch eyeballing”, designed to dispel guilt about the body, in which participants were instructed to look at each others genitals and disclose the sexual experiences they felt most guilty about while lying naked in a circle with their legs in the air.”

Joey Heatherton

Humans in the highest economic bracket leave more grandchildren through sons than through daughters. Therefore, adaptive variation in sex ratios is expected, and human mothers in the highest economic bracket do give birth to more sons, suggesting similar sex ratio manipulation as seen in other mammals.”

Results showed (a) that greater maternal harshness at 54 months predicted earlier age of menarche [and] (b) that earlier age of menarche predicted greater sexual (but not other) risk taking

Piper Laurie plays the mother of Carrie (Sissy Spacek) in the 1976 movie Carrie

A talk with Museum of Sex curator Sarah Forbes

The Museum of Eroticism in Paris — 7 floors of erotic art inside an old cabaret

The strippers of Shoreditch

A neat blog: Cabaret Berlin — “exploring the entertainment of the Weimar era”

July roundup

Elliott Gould, Natalie Wood, Robert Kulp, & Dyan Cannon in Bob & Carol & Ted & Alice

A new book, Sex at Dawn, argues that  monogamy goes against our nature. The book is favorably reviewed here. However,  while agreeing with several of the authors’ main claims, Jessa Crispin didn’t like this book. Hopefully, the book’s main idea will, if it catches on, reduce the impulse for mate guarding.

In male rats, sex promotes neurogenesis and reduces anxiety. More discussion here.

Men are attracted to women with smaller feet

A review of Sexual Coercion in Primates. The reviewer says that it’s only in the human and other primate species that females are “regularly abused by males,” but apparently male dolphins can be very abusive, too.

A summary of numerous lesion studies indicates that different areas of the brain, including forebrain and midbrain structures, work together to produce the complex repertoire of female sexual behavior. In addition, by investigating the effects of commonly addictive drugs, we are beginning to elucidate the role of dopaminergic neurotransmission in female sexual motivation.

Salmon & Symons (2001) examined slash (the depiction of a romantic or sexual relationship between typically heterosexual male television protagonists, such as Kirk and Spock from Star Trek) as an erotic genre, placing it in the context of romance and female sexual psychology. The topic is revisited here with attention also being paid to slash between two female television characters.

A group of neurons, identified in the lumbar spinal cord, has been proposed to constitute a spinal ejaculation generator. … Moreover, the fact that dopaminergic pathways are involved in sexual behavior and that [dopamine] (DA) release in some brain regions is an important facilitator of male sexual behavior reinforces the crucial implication of DA.

http://community.livejournal.com/retro_dome/490634.html#cutid1

Lieutenant Uhura (from Sensen's Retro_Dome at Live Journal)

Men and women viewed lower pitched voices in the opposite sex as being better at acquiring resources (e.g. hunting and gathering). While men preferred higher pitched women’s voices as marriage partners, women … who were currently breastfeeding had stronger preferences for higher pitched male voices whereas women not currently breastfeeding preferred lower pitched voices.

The voice analysis provided just as much information about a [male] speaker’s strength as photographs.”

Cougar sex: ‘Ticking Biological Clock Increases Women’s Libido‘. (But here’s a good critique of the study.)

Anne Bancroft & Dustin Hoffman in The Graduate

So might coffee: “Although caffeine did not disrupt preference for a sexual partner, caffeine selectively increased visits to the male [rat] when physical contact was possible. Collectively, these results suggest that the effects of caffeine on female mating behavior may reflect an increase in both sexual motivation and locomotor activity.

Romantic love fosters creativity while sexual desire promotes analytic thought

Some theories about why we have orgasms

The representation of male genitals in prehistoric art

Total pubic hair removal in women is associated with “cunnilingus in the past month and more positive genital self-image and sexual function.”

“In one field investigation of women’s nonverbal courtship signals at singles bars, a university snack bar, library and Women‟s Center, Moore catalogued ‘flirting behavior’ and identified ‘parade’ as a distinct form of walking” (pdf)

To see whether estrus was really ‘lost’ during human evolution … we examined ovulatory cycle effects on tip earnings by professional lap dancers. … Normally cycling participants earned about US$335 per 5-h shift during estrus, US$260 per shift during the luteal phase, and US$185 per shift during menstruation.

The classification system suggested by the author attempts to put all different shades of necrophilia under 10 classes.

Homosexual necrophilia in the mallard duck

If only the duck had hands, but then “compulsive masturbation can cause isolation, anxiety, relationship problems, and even difficulty with concentration and memory

Baker & Bellis hypothesize that “because there is a ‘shelf-life’ for sperm cells – they remain viable for only 5-7 days after production – and because adult human males manufacture a whopping 3 million sperm per day, masturbation is an evolved strategy for shedding old sperm while making room for new, fitter sperm.”

Have the feds gone soft on porn? Obscenity charges against Stagliano dismissed. Complete coverage from Reason.com

‘Bone bunnies’: Eizo’s X-ray pin-up calendar for radiologists

The beautiful game

Strategy, dolls and other primates

Nusch Eluard

Nusch Éluard (aka Maria Benz) More photos of her here

About those lovely Taschen books

From AlterNet: Why women pay for sex, the best movies about sex work, and the quasi-respectability of BDSM.

The ‘Godfather of masochism’ (and source of that label): “Herr Leopold von Sacher-Masoch gives his word of honor to Frau [Fanny] Pistor [aka Baroness Bogdanoff] to become her slave and …” (More links about Sacher-Masoch are in this earlier post.)

Kink as a reproductive strategy: “Kinky quails fertilize more eggs.

Sexsomnia — sexual acts while asleep — may be more common that thought

Oral sex as reproductive strategy: “Does oral sex confer an evolutionary advantage? Evidence from bats.” (Speaking of bats, here’s the Batman XXX trailer.)

Deception as a reproductive strategy: “How male antelopes lie to get more sex: with false alarm calls

Amy Marsh on “‘objectophiles,’ people who experience emotional, romantic, affectionate and/or sexual relationships with objects”

Sex Doll image from TokyoTimes.org

History of the sex doll , inc. a blurb about the WWII German sex doll, Borghild, who (despite rumors) has not been proven to be an inspiration for Barbie, although another German doll was, and that German doll has her own prurient past

The Portrayal of Women’s External Genitalia and Physique Across Time and the Current Barbie Doll Ideals

Koro: “the panic anxiety state in which affected males believe that the penis is shrinking and/or retracting, and perhaps disappearing” (ht)

Male physical competition, not attraction, was central in winning mates among human ancestors, according to a Penn State anthropologist.

Who should really be suffering from koro: “The average erect gorilla penis is 3cm (1.25 inches) long.” There’s a conflict in this linked story with the Penn State anthropologist’s theory, since the claim is made that human male’s have larger penises due to the selective pressures exerted by female preference. But I guess there can be more than one male reproductive strategy. Sadly, whichever strategy males deploy, it’ll shorten their lives.

We’re totally built for sex: According to that previous link about gorillas, human males have bigger penises than any other primates. Also, human females have bigger breasts and rounder tushes than any other primate.

A clitoris study: “The female clitoris and the male penis are really quite similar in anatomy”. From the comments there, I found a link to this intriguing story about Princess Marie Bonaparte and her studies of the vulva (with a focus on the distance between the clitoris and the vagina).

Sex tourism and … rational choice theory.

British women’s breasts are getting bigger.

Susannah Breslin on the White House’s stance on obscenity, a letter from Max Hardcore’s wife, and The tragic story of Stephen Hill

The dark side of male pregnancy …. Male pipefish selectively abort embryos from less attractive females.” I wonder how they gauged the attractiveness of female pipefish?

The Erotic Awards 2010: “Writers included Ernesto the Naked Poet – the pen name of a Basque cognitive scientist who describes his insecurities about his penis and then recites his work, naked.”

Claire Finch was tried for running a brothel in a sleepy village in Bedfordshire.

Waist-hip ratios, Neanderthals & spider sex

Ratio unspecified

The NY Times on a study showing that blind men, like men generally, are more attracted to women with a lower waist-to-hip ratio, indicating that this preference is not a result of visual media images (ht Mind Hacks)

Rutgers lab uses brain imaging to study female orgasm: “Dr. Barry Komisaruk selects volunteers to self-stimulate inside an fMRI machine so he and his team can study which areas of the brain … are activated by arousal.”

Differences between male & female brains

Simon Baron-Cohen on why biological differences between the sexes don’t support sexist stereotyping

Oxytocin makes men more sensitive

A Connecticut obstetrician-gynecologist who specialized in fertility treatments, opted to inseminate a patient with his own sperm, unbeknownst to the woman or her husband

Finkel and Eastwick speculated that in speed dating, physically approaching someone might be enough to make the potential date more appealing romantically—and thus, because men usually approach women in such events, to make the men less choosy overall

Why humans have sex

Yoko Ogawa’s Hotel Iris reviewed

A classic about cougars: the re-issue of Stephen Vizinczey’s In Praise of Older Women


‘Paraphilias Across Modern Cultures’: “Cultures define and describe what is normal and what is deviant” [doesn't biology contribute something on that score?]

Modern humans got it on with Neanderthals (or did they?)

The evolution of Raquel Welch

Porn star with a heart of gold– Lupe Fuentes flies to US to testify in court on behalf of a fan

Virginie Despentes on the power of porn stars

Porn makers on the cutting edge of techy computer stuff

A new study [of] … the erotic photographic shoot has been completed by two Canadian researchers

From an exhibit in Hamburg called ‘Nude Visions — 150 Years of Nude Photography‘:

http://www.thelocal.de/gallery/culture/817/15/

'Pulling on stockings' ca. 1855

We hypothesized that female choice is largely based on a courtship duration threshold in the Australian redback spider (Latrodectus hasselti) because females kill males before copulation is complete (premature cannibalism) and reduce their paternity if courtship is brief.

How male wasp spiders try to avoid being devoured by their siblings

Mature Argiope bruennichi [a type of spider] females are always receptive and never attack or reject males before mating, although sexual cannibalism after mating occurs regularly. Still, males usually perform an energetic vibratory display prior to copulation.

Recent (or not) sex news

Mata Hari

Mata Hari, who pioneered the ‘honey trap’ and Greta Garbo’s Mata Hari movie (1931), which is apparently hard to find in its uncensored form

Japan’s penis & vagina festivals: “These are folk rites going back at least 1,500 years, into Japan’s agricultural past. They’re held to ensure a good harvest and promote baby-making.”

Review of Oniroku Dan’s Season of Infedility

Sex toys from the 1700′s sold at auction: ‘Auctioneer Wendy Wood said: “You might laugh but it’s a good opportunity for investment. You won’t see another one in a long time.’”

The feminist porn awards, which were covered by Violet Blue

The plight of a feminist sex submissive

The maker of Baise-Moi, Virginie Despentes, is interviewed

An interview of the folks who made the MRI video of two people during sex:

‘Vacuum cleaner injury to penis’: “Five cases of significant penile trauma resulting from this form of masturbation are presented.” (ht NCBI)

More about sperm rivalry in insects and in voles

Angry Mouse’s righteous sex rant at Daily Kos

A catalogue of unconventional sex conventions

Disease-free society helps effeminate men attract women

Classic Spanish novel, La Celestina (1499): “Celestina is a procuress who restores hymens and sells the body of young maidens as virgins – over and over again.”

Mistresse Matisse on M. Febos’ Whip Smart

How Jewish editors helped shape Playboy‘s mind

An issue of Granta devoted to sex

On the pleasure of having naked women read to you

Shhh! A survey of librarians about sex

Formicophilia, “Fetish of having bugs crawl around on your genitalia

Olivia Judson on evolving sexual tensions (lots on sage-grouses)

Car crash leaves woman in a state of continual sexual arousal, or (to use the technical term), Persistent Sexual Arousal, which was covered by ABC News and is thought by some to be associated with increased soy intake. It’s been re-named Persistent Genital Arousal Disorder. Here’s another case, allegedly caused by a Wii Fit injury

Multiple Sclerosis can also cause hypersexuality

Sleeping Beauty Paraphilia — after head trauma, a man gets aroused by viewing sleeping women. “This case report highlights the potential link between paraphilia, deviant and aggressive sexual behaviour, neurological disturbance and self-representation.”

Epileptic seizures have been known to cause orgasms. In one case, the seizure-orgasm was triggered by toothbrushing

In the late 1890′s, half a century before Kinsey, Dr. Clelia Mosher surveyed women about their sexual practices

Mind Hacks on an article about heart attacks and sex: “All reported cardiac deaths surrounding sexual conduct involved extramarital sex, suggesting psychological stress as an added factor.”

The sad story of a sportswriter with gender dysphoria

The hijra of south Asia: “Asked whether the hijra family members were all congenital eunuchs and hermaphrodites, Nanni, 35, insisted that they were all born that way.” More on the hijra

Gandhi’s sex life

A book about the sexploits of Western men from Asia to North Africa over the past several centuries

Candy Barr was hot! And perky, very perky!

Hard-wired preferences, pelvic floor muscles & naked sled races

Sophia Loren

What distinguishes women with unusually high numbers of sex partners?

Which drugs are preferred by clubbers for sex?

The Rumpus visits the Adult Entertainment Expo in Vegas

How long should intercourse last?

Naked sled race draws 14000 in Germany

Bruno Schulz’s kinky drawings

France buys Casanova’s memoirs

While it is an accepted fact that suspension of the scrotum outside the abdominal cavity is paramount to the functional efficiency of testes in a preferred lower temperature – it still does not address the question – why hang at different levels?

As breast volume may be associated with heart cancer risk, we studied the relationship between breast volume, CYP1A2*1F and coffee intake.”

The reward centres of men’s brains fired up in response to the sight of naked women who’d chosen to have cosmetic surgery to accentuate the curviness of their figures. By contrast, a reduction in the women’s body mass index – increased slimness – had no such effect.”

Our concepts of physical beauty are rooted in our biology, shaped by natural selection, and not merely acquired tastes determined by culture and advertising” (ht IR)

Images with dark and medium areolar pigmentation were rated as more attractive than images with light areolae. However, variations in breast size had no significant effect on eye-tracking measures (initial visual fixations, number of fixations, and dwell times).”

Sophia Loren (from Blue Ruins tumblr)

Belarus declares Rammstein an enemy of the state due to its alleged promotion of ‘“violence, masochism, homosexuality and other perversions” that could “destroy the Belarusian state order.”’

Penile length was found to be statistically related to both body height and foot length, but with weak correlation coefficients. Height and foot size would not serve as practical estimators of penis length.”

Females of the bruchid beetle Callosobruchus maculatus are harmed by the spiny male genitalia during copulation but also appear to derive material benefits from the large ejaculates.”

The very long clitorises of cocksure hyenas

Potential evolutionary role for same-sex attraction

Evolution and romance novels

The authors of the study took a bunch of women, and checked the sexual function of women with strong pelvic floor muscles vs those with weak pelvic floor muscles. They assessed the strength of the pelvic floor by putting a finger in the vagina during the general exam, and asking the women to do a Kegel.”

Spencer Tunick — “documenting the live, nude figure in public”