Wednesday, 3 February 2010

Why Do Women Have Erotic Rape Fantasies?

A recent analysis of 20 studies over the last 30 years indicates that between 31% and 57% of women have rape fantasies, and these fantasies are frequent or preferred in 9% to 17% of women. Considering that many people are ashamed to report rape fantasies, these stats are most likely lowball figures.

In my personal experience, most women really appreciate subtle to moderate domination in the bedroom?a little forceful restraint, a little pain?as long as they feel safe. I had one girlfriend who wanted me to call her a slut, but that was pushing my boundaries. Though I didn't mind calling her naughty, etc., for expressing pleasure at whatever I was doing to her. The whole "you shouldn't like this but I know you do" routine. She explained that sexuality was taboo in her household growing up. So pretending that she was being corrupted by someone else freed her to go along with the illicit activities and indulge in her repressed desires. Not all of our play followed this narrative, but when it did, the temperature rose.
Research into rape fantasies hasn't been particularly well publicized. Many people don't want to acknowledge that women have them, for fear that the news will incite or excuse real rape: "See? Women want it after all!" But I follow the Kinsey line that it's better to study the disturbing parts of human sexuality than to keep them in the dark.

So do Joseph Critella and Jenny Bivona, the researchers at the University of North Texas who published the meta-analysis mentioned above in the Journal of Sex Research in January. They combined 20 studies and a whole field of theory to evaluate eight potential explanations for women's rape fantasies. Some of the explanations overlap with each other, and others mutually contradict. Here's a summary:

?Masochism - The idea that women desire suffering. Women who engage in masochistic sex are more likely to have rape fantasies, but the great majority of women with rape fantasies do not want real rape. Accordingly, masochism may only apply to a small group of women.

?Sexual Blame Avoidance - (See my ex, above.) Women are socialized to not seek out sex lest they be considered tramps, but if they're having sex against their will they can avoid guilt. Studies comparing sexual repression to rape fantasies are mixed and overall don't support the explanation, but they may have been using wrong metrics; sexually repressed women have fewer fantasies overall but they might have a higher ratio of rape fantasies. In any case, this theory would only apply to some women.

?Openness to Sexual Experience - In some ways this is the opposite of the last one, and it doesn't explain rape fantasies so much as it describes the type of person to have them. If you're sexually open, you entertain a greater variety of fantasies. As one study described rape fantasy among these women, it's "just one more expression of a generally open, positive, unrestrictive, and relatively guilt-free expression of one's sexuality."

?Desirabilty - Many women like to believe that they're so attractive that men cannot resist the urge to overtake them. The evidence for this theory is suggestive but not yet conclusive. I did cover a study in Psychology Today last year indicating that women with attachment anxiety (neediness) have more sexual fantasies featuring submission.

?Male Rape Culture - Some have argued that women have been conditioned to buy into men's fantasies of domination. But the prevalence of rape fantasies has not changed much in recent decades, even as gender roles have.
?Biological Predisposition to Surrender - In many mammalian species, the male must pursue and subdue the female in order to mate. Women may be programmed to surrender to the successful dominant male. Just like many other theories in evolutionary psychology, this one makes sense but has not been tested empirically. (Writer Tracie Egan hints at this explanation in her essay entitled "One Rape Please (To Go)" about hiring a male prostitute to play-rape her (which I recently saw her read live): " a girl, my equipment can be trickier to manage, therefore I need to be a boss in the bedroom to ensure I get worked the right way. [But] it gets really tiresome always being the one in charge...")

?Sympathetic Activation - The sympathetic nervous system becomes engaged in times of stress or danger, activating a fight or flight response marked by increased heart rate, respiration, pupil dilation, and genital arousal. Just like on a roller coaster, fear and excitement go hand in hand.

?Adversary Transformation - In one survey of romance novels (which tend to be written by and for women), the lead female character was raped in 54%. The male heroes are usually rugged warrior types and these books may illustrate a desire to "conquer the heart of the rapist" and tame him for marriage.

?Reaction to Trauma - This one is not mentioned in the paper, but Brett Kahr, a psychoanalyst who has conducted the largest survey of sexual fantasies ever, argues that most masturbatory fantasies are attempts to transform early difficult experiences into pleasure. So those who have been sexually abused may try to master their trauma by taming those experiences.
I asked Kahr whether it's unhealthy to entertain rape fantasies. "At one level, they pose little problem because they represent a highly normative part of female sexual fantasy," he said; many women have them, and most of these woman easily distinguish between reality and fantasy. But in some cases it may recapitulate forgotten abuse that hasn't been processed properly, or it may reflect masochistic tendencies. A woman should see a professional if she's troubled by her fantasies. Julie Shulman, a clinical psychology professor at Alliant International University who has studied rape fantasies [pdf] also told me "the sexual and emotional health of such engagement can differ greatly," and would like to see more research on the topic.

Should women share their rape fantasies with their partners? "Obviously, a loving, committed, sympathetic man would respond delicately and sensitively to such news," Kahr said, "but a more sadistic partner (with conscious or unconscious sadism towards a woman)" might use the information more destructively. "One must proceed cautiously."

I asked my friend Rachel Kramer Bussel, an editor at Penthouse who has written about rape fantasies for the Village Voice, whether she thought it was unhealthy to act them out with men. She said it's not unhealthy per se: "At the end of the day, the woman has control over it, and it can be hot to give yourself over completely to someone within that context knowing that you can trust them."

Rachel added that "it's probably a tricky fantasy for men, as that is something that's inculcated into them not to do." I covered a study supporting such inhibition in the April issue of Psychology Today; it showed that men are slower to recognize words associated with dominance (coerce, fierce, etc.) if they've been primed with sex-related words (climax, oral, etc.) Pretending to rape someone, Rachel says, is "a lot of responsibility to assume, and if you're dealing with a woman who does have a history of sexual abuse in her past, it's extra thorny."

Youngest prostitute

Child prostitution has always existed in history. Temple harlots were as young as six and seven; and in China boys as young as four years were trained "in the fine art of passive pederasty;" girl and boy brothels were common in the ancient world and in more modern times also. The Chinese boy prostitutes were sanctified by Tcheou-Wang, God of Sodomy. Without doubt the youngest prostitutes of all were the babies in the brothels of ancient Rome. It has been noted that "sucking babes" were introduced into the brothels. The Emperor Domitian was praised when he attempted to stamp out all forms of infant prostitution. In the Japanese Yoshiwara or Whores' Quarter, little girls were kept for fellatio. The high-status geishas, contrary to some imaginings, were only available for vaginal coitus.

Longest human clitoris

Clitoris size has only rarely been of importance in human society.
A few communities -- Ford and Beach mention the Easter Islanders -- have favoured the large clitoris and some natives have tried with varying degrees of success to enlarge this organ in their girls. For the most part however, with a prevailing indifference in the nineteenth-century and early part of the twentieth-century to sexual arousal in women, the clitoris has been neglected. Needless to say, it varies in size.
How big are the largest? Theo Lang in "The Difference Between a Man and a Woman" mentions one recorded instance of a woman having a clitoris 2 in. long, and 3 in. "when fully erect". Pomeroy has remarked that clitorises measuring more than 1 in. are very rare in whites, but may occur in 2 or 3 per cent of blacks "measurements of 3 in. and more were obtained from perhaps one out of 300 or 400 black women". Benjamin and Masters note in "The Prostitute in Society" that Parent-Duchalet came across a clitoris that measured 3.14 in.

The eighteenth-century Swiss biologist, Albrecht von Haller, is said to have come across a woman with a monstrous clitoris no less than 7 in. long. But the record clitoris is almost certainly the 12 in. specimen mentioned by various writers and quoted (without comment) by W. Francis Benedict in "The Sexual Anatomy of Women".

Largest human penis

We all know that men are supposed to worry endlessly about penis size. In popular mythology a small organ is still thought to signal a totally inadequate lover. All the best books tell us that this idea is absurd but nonetheless the notion persists.
What can we say of penis size? How big is the biggest? One problem is who is to do the measuring. If men measure their own organs they are likely to exaggerate the results: it is not an area in which there are abundant objective surveys. And women too may exaggerate the size of a particular penis in their acquaintance
Walter (of My Secret Life) demonstrated this clearly enough: a woman spoke of a penis as being 7-in. long or even more - yet the "very large penis" measured by Walter turned out to be significantly less than 7 in. According to Wardell B. Pomeroy, the Kinsey co-worker, the longest penis encountered was ten inches. This figure accords quite well with the results of the special Forum survey into penis size. In this careful and detailed survey, published in 1970, the largest penis was found to be 9? in. in erection, hardly able to compete with the vast organs of pornographic fiction.

In an earlier inter-racial survey, Dr. Jacobus's 1935 publication - "L'Ethnologie du Sens Genitale", larger dimensions were recorded. In this survey, organs nearly 12 in. in length are reported. Of all penis sizes quoted in the literature the largest is unquestionably the 14 in. erect organ mentioned by Dr. David Reuben in "Everything You Always Wanted to Know About Sex". But as no source is quoted perhaps we should not take too much notice of this figure. The largest well attested penises would seem to be between ten and twelve inches in the erect state.

The Perfect Penis Size According To Women

If you have questioned the phrase ?Does size matter?? then you may have wondered if you are of adequate size. The fact is size DOES matter when it comes to the size of your penis and how women feel about it.

The size of the average penis is about 6 inches which may make you happy or depressed depending on how you measure up. Most women are very content with the 6 inch penis because typically it is not always the length that is as important. Many women say that it doesn?t always matter what the length is, because the girth is just as important. Many women feel generally that 6 to 7 inches is very normal for men and that it does provide enjoyment and pleasure in sex. However, women are much more thrilled when they see a penis that is at least 5 inches in girth.

Most women squeal with delight if the girth is about 6 inches, and although it is a bit above the norm, it is not unusual to find. That one inch makes an incredible difference when it comes to the overall enjoyment while having sex. If you aren?t quite that large in diameter it doesn?t mean that you should forego sex for the rest of your life. The fact that you know what women want now is just the beginning.

There are many things you can do to enhance the girth of your penis. There are many supplements that you can take that will give you the bigger penis that you want, often in less time then even the product tells you. For a hassle free way to get a larger penis there are Extenze pills. In just a matter of weeks you will have a bigger penis to satisfy your partner. Another supplement that is making men and women very happy are Semenax Pills. This will give you a much harder erection which will make for some out of this world orgasms for both you and your partner. Lastly, you have the small patch that you can wear anywhere you go. You merely place it on your body so that it is hidden under your clothes where it slowly pumps a unique blend of herbs into your body that helps to increase the size of your penis.

You no longer have to be content with a smaller penis size. Even by doing penis exercises you can gain more inches in the girth of your penis as well as better control. With these exercises you can have better erections that you have more power over. The next time you have sexual intercourse you will not only please your partner, but you will have the benefit of more pleasure yourself.

To further explore the area of penis enlargement and male orgasm enhancement, you may visit two sites that we recommend: Semenax and Extenze, both of which have substantial positive track records of success.

How to Tell If Your Vagina is Perfect - The Ideal Vagina Has to Be This?

What gives me the impression that your here because you are concerned you may have an abnormal vagina or you know someone that has (girlfriend.) Before going further let`s put you out of your misery. There is no such thing as an abnormal vagina. Abnormal is a word which refers to something that is not considered "usual", see the way I evaded the word "normal" and used usual because the same applies. What is meant here is the vagina may look different (not abnormal) that`s all. So no you don`t have an abnormal vagina but maybe one that is different.

What should be your concern is having a healthy vagina. Think about it; look at the women with different shaped faces, body size and hair color, which of these are considered normal "none" because this is how we were all born with differences. Nevertheless if you`re not swayed by the facts and still worry then let us explain using the words normal and abnormal.

Unless your vagina turns penis then this is not accepted as normal. What is normal anymore when you see some people changing their gender choosing the penis over the vagina? How can the vagina ever be perfect with foreskin.

The odds of your vagina being different to that of the next woman`s is very slim. Differences only occur if the pubic hair is colored styled or shaved. Keep your vagina healthy to have peace of mind. Poor genital hygiene causes other vaginal issues. Overall health of the entire body will contribute greatly towards keeping the vagina in good shape. Bathing is important to tackle build up of sweat and greasy skin oils round the genitals which can lead to vaginal infections and odors. Some women find this advice somewhat misleading as to what is the best solution because, too much bathing is not good, and to less is not good either. Only you know when water and soap is needed. No need for harsh elbow grease because the vagina is a self cleaning organ and is also odorless. If your vagina smells then it is caused by something other than the vagina itself. More women think they are doing themselves a favor by douching, well you`re not. While a douche removes "little" bad bacteria, it at the same time takes more good bacteria away. Douching can cause inflammation (vaginitis).

If you are sexually active then use condoms because these too help keep the vagina clean. Condom use is needed for preventing an unwanted pregnancy or sexually transmitted disease. If you have genital discomfort go commando if possible (knicker-less) if this suggestion unnerves you then avoid nylon material, no matter how sexy the thong or other, opt for cotton briefs. The vagina/anus needs room to breathe, so let it. Women experience vaginal odor at the time of menstruation, the solution is to remove sanitary protection regular (tampons and pads.)

There is much debate over what is the "perfect vagina?" and the argument is normally fought among women themselves. In my opinion a perfect vagina is a healthy one. Every woman differentiates greatly i.e. shape and size and because of this the vagina is affected, meaning, if you `re fat then the vagina looks spaced out and wide too but this does not insinuate the vaginal entrance is big. In fact the big woman`s vagina may be tighter that the skinny woman`s.

A healthy vagina is as clean and pure as a carton of yoghurt says Dr Hillier from the Magee-Woman`s hospital in Pittsburgh. The vagina is by no means dirty as some would have it. A healthy vagina is a self regulating system and would you believe is cleaner than the mouth and bum. The vaginal ecosystem is a jointly beneficial partnership between the vagina itself and the micro-organisms that exist here. The vagina is filled with bacteria, however all good and destroys the bad bacteria out of the reproductive system. The good bacteria known as lactobacilli are the same organisms contained in yoghurt. In a healthy vagina these lactobacilli maintain an acidic environment - around 3.8 - 4.5 pH.

Vaginal mucus is not a very nice word but one used and appropriate to help with vaginal explanations. Vaginal mucus is "made up and akin to the things found in blood serum, the lucid, thin, sticky fluid that stays behind when the solid components of blood, like clot issues, are separated away. Vaginal discharge consists of water, albumin - the most copious protein in the human body - a few lost white blood cells, and mucin, the oily matter that gives the vagina and cervix their greasy sheen. Discharge is not a toxic waste product of the body in the sense of urine and faeces.

Is the vagina abnormal because it smells, certainly not? A healthy vagina will however have a "slight" odor but nevertheless if "slight" turns strong (fishy odour) then this is usually a sign that the delicate balance has been upset and the Lactobacilli is not doing the job it should..

If the balance in the vagina is upset it can cause the vaginal infection "bacterial vaginosis."

Sufficient bathing for the vagina`s outer part "labia," should be done twice a day with cold water. Cold is best because the genitals is already moist and warm which is a problem for allowing bacteria to grow. Scented products can cause vaginal thrush. Pelvic Infections can lead to vaginosis. Candida is a condition where the vagina becomes too alkaline, primarily brought about by diet, oral contraceptives even stress. Pregnancy and the resultant change in your hormone levels can cause thrush. Antibiotics although given for curing and healing along with oral contraceptives and can lead to vaginosis. Low levels of lactobacilli leave particular women more susceptible to infections because they may have fewer robust lactobacilli. How to maintain a healthy Vagina

Forget cleaning the inside of the vagina, it is not necessary. Your vagina will be no less healthy from not doing this. The vagina regularly flushes itself out. Avoid particular soaps because they can upset the natural balance of substances. You are at risk of developing a vaginal infection through specific product misuse. Do not douche. The only exception to this rule which may be acceptable for douching is if you`re trying to conceive or trying to alter your vaginas pH for a greater good. Do it as little as possible and increase the number of lactobacilli in your diet. Add yoghurt to your daily diet or take acidophilus tablets. Consult with your doctor over issues about pregnancy and suggested medicines.

Use condoms to keep the vagina clean and healthy and for protecting against unwanted pregnancies or STDs.

Wear cotton underwear - to allow good air flow.

Avoid using perfumes/sprays round the genitals.

The way to avoid excess bacteria developing round the vagina/urethra is change motion when cleaning after bowel movement Clean from the front towards the back. Clean the anus last as contamination can spread doing otherwise. Vaginal discharge is a necessary part of the body's regular function, however if it shows different have yourself checked over. Should the change in discharge be caused by infection then soap and water will not cure it, it will need antibiotics. Vaginal discharge is normally clear to white; changes in consistency and color are signs to say to call on your GP. Swap tissue to clean the vagina after urinating with a damp cloth. Using tissue has one tend to give a quick wipe, whereas with a cloth it urges the person to wash.

Good cleansing will see less chance of urinary tract infections (UTI's) happening.

Wednesday, 20 January 2010

Secrets of the Phallus: Why Is the Penis Shaped Like That?

If you?ve ever had a good, long look at the human phallus, whether yours or someone else?s, you?ve probably scratched your head over such a peculiarly shaped device. Let?s face it?it?s not the most intuitively shaped appendage in all of evolution. But according to evolutionary psychologist Gordon Gallup of the State University of New York at Albany, the human penis is actually an impressive ?tool? in the truest sense of the word, one manufactured by nature over hundreds of thousands of years of human evolution. You may be surprised to discover just how highly specialized a tool it is. Furthermore, you?d be amazed at what its appearance can tell us about the nature of our sexuality.

The curious thing about the evolution of the human penis is that, for something that differs so obviously in shape and size from that of our closest living relatives, only in the past few years have researchers begun to study it in any detail. The reason for this neglect isn?t clear, though the most probable reason is because of its intrinsic snicker factor or, related to this, the likelihood of its stirring up uncomfortable puritanical sentiments. It takes a special type of psychological scientist to tell the little old lady sitting next to him on a flight to Denver that he studies how people use their penises when she asks what he does for a living. But I think labeling it as a ?crude? or ?disgusting? area of study reveals more about the critic than it does the researcher. And if you think there?s only one way to use your penis, that it?s merely an instrument of internal fertilization that doesn?t require further thought, or that size doesn?t matter, well, that just goes to show how much you can learn from Gallup?s research findings.

Gallup?s approach to studying the design of the human penis is a perfect example of of ?reverse-engineering? as it?s used in the field of evolutionary psychology. This is a logico-deductive investigative technique for uncovering the adaptive purpose or function of existing (or ?extant?) physical traits, psychological processes, or cognitive biases. That is to say, if you start with what you see today?in this case, the oddly shaped penis, with its bulbous glans (the ?head? in common parlance), its long, rigid shaft, and the coronal ridge that forms a sort of umbrella-lip between these two parts?and work your way backward regarding how it came to look like that, the reverse-engineer is able to posit a set of function-based hypotheses derived from evolutionary theory. In the present case, we?re talking about penises, but the logic of reverse-engineering can be applied to just about anything organic, from the shape of our incisors, to the opposability of our thumbs, to the arch of our eyebrows. For the evolutionary psychologist, the pressing questions are, essentially, ?why is it like that?? and ?what is that for?? The answer isn?t always that it?s a biological adaptation?that it solved some evolutionary problem and therefore gave our ancestors a competitive edge in terms of their reproductive success. Sometimes a trait is just a ?by-product? of other adaptations. Blood isn?t red, for example, because red worked better than green or yellow or blue, but only because it contains the red hemoglobin protein, which happens to be an excellent transporter of oxygen and carbon dioxide. But in the case of the human penis, it appears there?s a genuine adaptive reason that it looks the way it does.

If one were to examine the penis objectively?please don?t do this in a public place or without the other person?s permission?and compare the shape of this organ to the same organ in other species, they?d notice the following uniquely human characteristics. First, despite variation in size between individuals, the erect human penis is especially large compared to that of other primates, measuring on average between five and six inches in length and averaging about five inches in circumference. (Often in this column I?ll relate the science at hand to my own experiences, but perhaps this particular piece is best written without my normally generous use of anecdotes.) Even the most well-endowed chimpanzee, the species that is our closest living relative, doesn?t come anywhere near this. Rather, even after correcting for overall mass and body size, their penises are about half the size of human penises in both length and circumference. I?m afraid that I?m a more reliable source on this than most. Having spent the first five years of my academic life studying great ape social cognition, I?ve seen more simian penises than I care to mention. I once spent a summer with a 450-pound silverback gorilla that was hung like a wasp (great guy, though) and baby-sat a lascivious young orangutan that liked to insert his penis in just about anything with a hole, which unfortunately one day included my ear.

In addition, only our species has such a distinctive mushroom-capped glans, which is connected to the shaft by a thin tissue of frenulum (the delicate tab of skin just beneath the urethra). Chimpanzees, gorillas and orangutans have a much less extravagant phallic design, more or less all shaft. It turns out that one of the most significant features of the human penis isn?t so much the glans per se, but rather the coronal ridge it forms underneath. The diameter of the glans where it meets the shaft is wider than the shaft itself. This results in the coronal ridge that runs around the circumference of the shaft?something Gallup, by using the logic of reverse-engineering, believed might be an important evolutionary clue to the origins of the strange sight of the human penis.

Now, the irony doesn?t escape me. But in spite of the fact that this particular evolutionary psychologist (yours truly) is gay, for the purposes of research we must consider the evolution of the human penis in relation to the human vagina. Magnetic imaging studies of heterosexual couples having sex reveal that, during coitus, the typical penis completely expands and occupies the vaginal tract, and with full penetration can even reach the woman?s cervix and lift her uterus. This combined with the fact that human ejaculate is expelled with great force and considerable distance (up to two feet if not contained), suggests that men are designed to release sperm into the uppermost portion of the vagina possible. Thus, in a theoretical paper published in the journal Evolutionary Psychology in 2004, Gallup and coauthor, Rebecca Burch, conjecture that, ?A longer penis would not only have been an advantage for leaving semen in a less accessible part of the vagina, but by filling and expanding the vagina it also would aid and abet the displacement of semen left by other males as a means of maximizing the likelihood of paternity.?

This ?semen displacement theory? is the most intriguing part of Gallup?s story. We may prefer to regard our species as being blissfully monogamous, but the truth is that, historically, at least some degree of fooling around has been our modus operandi for at least as long we?ve been on two legs. Since sperm cells can survive in a woman?s cervical mucus for up to several days, this means that if she has more than one male sexual partner over this period of time, say within 48 hours, then the sperm of these two men are competing for reproductive access to her ovum. According to Gallup and Burch, ?examples include, group sex, gang rape, promiscuity, prostitution, and resident male insistence on sex in response to suspected infidelity.? The authors also cite the well-documented cases of human heteroparity, where ?fraternal twins? are in fact sired by two different fathers who had sex with the mother within close succession to each other, as evidence of such sexual inclinations.

So how did natural selection equip men to solve the adaptive problem of other men impregnating their sexual partners? The answer, according to Gallup, is their penises were sculpted in such a way that the organ would effectively displace the semen of competitors from their partner?s vagina, a well-synchronized effect facilitated by the ?upsuck? of thrusting during intercourse. Specifically, the coronal ridge offers a special removal service by expunging foreign sperm. According to this analysis, the effect of thrusting would be to draw other men?s sperm away from the cervix and back around the glans, thus ?scooping out? the semen deposited by a sexual rival.

You might think that?s fine and dandy, but one couldn?t possibly prove such a thing. But you?d be underestimating Gallup, who in addition to being a brilliant evolutionary theorist, happens also to be a very talented experimental researcher (among other things, he?s also well-known for developing the famous mirror self-recognition test for use with chimpanzees back in the early 1970s). In a series of studies published in a 2003 issue of the journal Evolution & Human Behavior, Gallup and a team of his students put the ?semen displacement hypothesis? to the test using artificial genitalia of different shapes and sizes. They even concocted several batches of realistic seminal fluid. Findings from the study may not have ?proved? the semen displacement hypothesis, but it certainly confirmed its principal points and made a believer out of most readers.

Here?s how the basic study design worked. (And perhaps I ought to preempt the usual refrain by pointing out firstly that, yes, Gallup and his co-authors did receive full ethical approval from their university to conduct this study.) The researchers selected several sets of prosthetic genitals from erotic novelty stores, including a realistic latex vagina sold as a masturbation pal for lonely straight men and tied off at one end to prevent leakage, and three artificial phalluses. The first latex phallus was 6.1 inches long and 1.3 inches in diameter with a coronal ridge extending approximately 0.20 inch from the shaft. The second phallus was the same length, but its coronal ridge extended only 0.12 inch from the shaft. Finally, the third phallus matched the other two in length, but lacked a coronal ridge entirely. In other words, whereas the first two phalluses closely resembled an actual human penis, varying only in the coronal ridge properties, the third (the control phallus) was the bland and headless horseman of the bunch.

Next, the authors borrowed a recipe for simulated semen from another evolutionary psychologist, Todd Shackleford from Florida Atlantic University, and created several batches of seminal fluid. The recipe ?consisted of 0.08 cups of sifted, white, unbleached flour mixed with 1.06 cups of water. This mixture was brought to a boil, simmered for 15 minutes while being stirred, and allowed to cool.? In a controlled series of ?displacement trials,? the vagina was then loaded with semen, the phalluses were inserted at varying depths (to simulate thrusting) and removed, whereupon the latex orifice was examined to determine how much semen had been displaced from it. As predicted, the two phalluses with the coronal ridges displaced significantly more semen from the vagina (each removed 91 percent) than the ?headless? control (35.3 percent). Additionally, the further that the phalluses were inserted?that is to say, the deeper the thrust?the more semen was displaced. When the phallus with the more impressive coronal ridge was inserted three fourths of the way into the vagina, it removed only a third of the semen, whereas it removed nearly all of the semen when inserted completely. Shallow thrusting, simulated by the researchers inserting the artificial phallus halfway or less into the artificial vagina, failed to displace any semen at all. So if you want advice that?ll give you a leg up in the evolutionary arms race, don?t go West, young man?go deep.

In the second part of their study published in Evolution & Human Behavior, Gallup administered a series of survey questions to college-age students about their sexual history. These questions were meant to determine whether penile behavior (my term, not theirs) could be predicted based on the men?s suspicion of infidelity in their partners. In the first of these anonymous questionnaires, both men and women reported that, in the wake of allegations of female cheating, men thrust deeper and faster. Results from a second questionnaire revealed that, upon first being sexually reunited after time apart, couples engaged in more vigorous sex?namely, compared to baseline sexual activity where couples see other more regularly, vaginal intercourse following periods of separation involve deeper and quicker thrusting. Hopefully you?re thinking as an evolutionary psychologist at this point and can infer what these survey data mean: by using their penises proficiently as a semen displacement device, men are subconsciously (in some cases consciously) combating the possibility that their partners have had sex with another man in their absence. The really beautiful thing about evolutionary psychology is that you don?t have to believe it?s true for it to work precisely this way. Natural selection doesn?t much mind if you favor an alternative explanation for why you get so randy upon being reunited with your partner. Your penis will go about its business of displacing sperm regardless.

There are many other related hypotheses that can be derived from the semen displacement theory. In their 2004 Evolutionary Psychology piece, for example, Gallup and Burch expound on a number of fascinating spin-off ideas. For example, one obvious criticism of the semen displacement theory is that men would essentially disadvantage their own reproductive success by removing their own sperm cells from their sexual partner. However, in your own sex life, you?ve probably noticed the ?refractory period? immediately following ejaculation, during which males almost instantly lose their tumescence (the erection deflates to half its full size within 1 min of ejaculating), their penises become rather hypersensitive and further thrusting even turns somewhat unpleasant. In fact, for anywhere between 30 minutes to 24 hours, men are rendered temporarily impotent following ejaculation. According to Gallup and Burch, these post-ejaculatory features, in addition to the common ?sedation? effect of orgasm, may be adaptations to the problem of ?self-semen displacement.?

Gallup and Burch also leave us with a very intriguing hypothetical question. ?Is it possible (short of artificial insemination),? they ask, ?for a woman to become pregnant by a man she never had sex with? We think the answer is ?yes.?? It?s a tricky run to wrap your head around, but basically Gallup and Birch say that semen displacement theory predicts that this is possible in the following way. I?ve taken the liberty of editing this for clarity. Also note that the scenario is especially relevant to uncircumcised men.

If ?Josh? were to have sex with ?Kate? who recently had sex with ?Mike,? in the process of thrusting his penis back and forth in her vagina, some of Mike?s semen would be forced under Josh?s frenulum, collect behind his coronal ridge, and displaced from the area proximate to the cervix. After Josh ejaculates and substitutes his semen for that of the other male, as he withdraws from the vagina some of Mike?s semen will still be present on the shaft of his penis and behind his coronal ridge. As his erection subsides the glans will withdraw under the foreskin, raising the possibility that some of Mike?s semen could be captured underneath the foreskin and behind the coronal ridge in the process. Were Josh to then have sex with ?Amy? several hours later, it is possible that some of the displaced semen from Mike would still be present under his foreskin and thus may be unwittingly transmitted to Amy who, in turn, could then be impregnated by Mike?s sperm.