Noteworthy News Articles on Mental Health Topics, April 10-14, 2007

Everybody with a pair of currently or formerly active gonads knows about sexual desire. It is a near-universal experience, the invisible clause on one’s birth certificate stipulating that one will, upon reaching maturity, feel the urge to engage in activities often associated with the issuance of more birth certificates.

Yet universal does not mean uniform, and the definitions of sexual desire can be as quirky and personalized as the very chromosomal combinations that sexual reproduction will yield. Ask an assortment of men and women, “What is sexual desire, and how do you know you’re feeling it?” and after some initial embarrassed mutterings and demands for anonymity, they answer as follows:

“There’s a little bit of adrenaline, a puffing of the chest, a bit of anticipatory tongue motion,” said a divorced lawyer in his late 40s.

“I feel relaxed, warm and comfortable,” said a designer in her 30s.

“A yearning to kiss or grab someone who might respond,” said a male filmmaker, 50. “Or if I’m alone, to call up exes.”

“Listening to Noam Chomsky,” said a psychologist in her 50s, “always turns me on.”

For researchers in the field of human sexuality, the wide variance in how people characterize sexual desire and describe its most salient features is a source of challenge and opportunity, pleasure and pain. “We throw around the term ‘sexual desire’ as though we’re all sure we’re talking about the same thing,” said Lisa M. Diamond, an associate professor of psychology at the University of Utah. “But it’s clear from the research that people have very different operational definitions about what desire is.”

At the same time, the researchers said, it is precisely the complexity of sexual desire, the depth, richness and tangled spangle of its weave, that call out to be understood.

An understanding could hardly come too soon. In an era when the rates of sexually transmitted diseases continue to climb; when schools and parent groups spar bitterly over curriculums for sex education classes; when the Food and Drug Administration angers both religious conservatives and women’s groups by approving the sale of the morning-after pill over the counter but then limiting those sales to women 18 years or older; and when deviations from the putative norm of monogamous heterosexuality are presented as threats to the social fabric — at such a time, scientists argue that the clear-eyed study of sexual desire and its consequences is vital to public health, public sanity, public comity.

“Sexual desire may be complicated, but that doesn’t mean it’s chaotic,” said Julia R. Heiman, director of the Kinsey Institute for Research in Sex, Gender and Reproduction in Bloomington, Ind. “We can make an honest attempt to understand what sexual desire is and what it is not, and that it is important to do so.”

Meredith L. Chivers, a researcher at the Center for Addiction and Mental Health in Toronto, concurs. “Sexuality is such a huge part of who we are. How could we not want to understand it?”

Unabashed about acting on their academic appetites, sexologists have gained a wealth of new and often surprising insights into the nature and architecture of sexual desire. They are tracing how men and women diverge in their experience, and where they converge. They are learning how and why people pursue the erotic partners they do, and the circumstances under which those tastes are either fixed or fluid.

Some researchers are delving into the neural, anatomical and emotional mechanisms that modulate and micromanage sexual desire and sexual arousal; others are exploring the role that culture plays in plucking or muffling the strings of desire. The pragmatists in sexology’s ranks are seeking better bedside medicines — new ways to help people who feel they suffer from an excess or deficit of sexual desire.

One recent standout discovery upends the canonical model of how the typical sex act unfolds, particularly for women but very likely for men as well.

According to the sequence put forward in the mid-20th century by the pioneering sex researchers William H. Masters, Virginia E. Johnson and Helen Singer Kaplan, a sexual encounter begins with desire, a craving for sex that arises of its own accord and prods a person to seek a partner. That encounter then leads to sexual arousal, followed by sexual excitement, a desperate fumbling with buttons and related clothing fasteners, a lot of funny noises, climax and resolution (I will never drink Southern Comfort at the company barbecue again).

A plethora of new findings, however, suggest that the experience of desire may be less a forerunner to sex than an afterthought, the cognitive overlay that the brain gives to the sensation of already having been aroused by some sort of physical or subliminal stimulus — a brush on the back of the neck, say, or the sight of a ripe apple, or wearing a hard hat on a construction site and being surrounded by other men in similar haberdashery.

In a series of studies at the University of Amsterdam, Ellen Laan, Stephanie Both and Mark Spiering demonstrated that the body’s entire motor system is activated almost instantly by exposure to sexual images, and that the more intensely sexual the visuals, the stronger the electric signals emitted by the participants’ so-called spinal tendious reflexes. By the looks of it, Dr. Laan said, the body is primed for sex before the mind has had a moment to leer.

“We think that sexual desire emerges from sexual stimulation, the activation of one’s sexual system,” she said in a telephone interview.

Moreover, she said, arousal is not necessarily a conscious process. In other experiments, Dr. Spiering and his colleagues showed that when college students were exposed to sexual images too fleetingly for the subjects to report having noticed them, the participants were nevertheless much quicker to identify subsequent sexual images than were the control students who had been flashed with neutral images.

“Our sexual responsiveness can be activated or enhanced by stimuli we’re not even aware of,” Dr. Laan said.

By reordering the sexual timeline and placing desire after arousal, rather than vice versa, the new research fits into the pattern that neurobiologists have lately observed for other areas of life. Before we are conscious of wanting to do anything — wave at a friend, open a book — the brain regions needed to perform the activity are already ablaze. The notion that any of us is the Decider, the proactive plotter of our most lubricious desires, scientists say, may simply be a happy and perhaps necessary illusion.

The new findings also suggest that in some cases, the best approach for treating those who suffer from low sex drive may be to focus on enhancing arousability rather than desire — to forget about sexy thoughts and to emphasize sexy feelings, the physical cues or activities that arouse one’s sexual circuitry. The rest will unwind from there, with the ease of a weighted shade.

Researchers have also gathered considerable evidence that the sensations of sexual arousal, desire and excitement are governed by two basic and distinctively operating pathways in the brain — one that promotes sexual enthusiasm, another that inhibits it. An originator of this novel concept, Erick Janssen of the Kinsey Institute, compares these mechanisms to the pedals of a car.

“If you let go of the gas pedal, you’ll slow down,” he said, “but that’s not the same as stepping on the brakes.”

In any given individual, each pedal may be easier or harder to press. One person may be quick to become aroused, but equally quick to stifle that response at the slightest distraction. Another may be tough to get started, but once galvanized “will not lose sexual arousal even if the ceiling comes down,” Dr. Janssen said. Still another may be saddled with both a feeble sexual accelerator and an overzealous sexual inhibitor, an unenviable pairing most likely correlated with a taste for beige pantsuits and the music of Loggins and Messina.

Dr. Janssen and his colleagues have developed extensive questionnaires to measure individual differences in sexual excitability and inhibition, asking participants how strongly they agree or disagree with statements like “When I am taking a shower or a bath, I easily become sexually aroused” and “If there is a risk of unwanted pregnancy, I am unlikely to get sexually aroused.”

The researchers have also explored the physiological, emotional and cognitive underpinnings associated with high scores and low. In one recent study, they recruited 40 male undergraduates and determined by questionnaire the subjects’ relative degree of sexual excitability and inhibition. Each participant was then ushered into a plush, private room with low lighting, a comfortable recliner and a television monitor and instructed in how to place the aptly named Rigiscan device on his genitals.

Thus outfitted, the student s watched a series of erotic film clips, some classified as “nonthreatening” and depicting couples engaged in mutually animated consensual sex, others of a “threatening” variety featuring coercive, violent sex.

Analyzing the excitability and inhibition variables separately, the researchers found that the men who had scored high on the questionnaire in sexual excitability showed, on average, a swifter and more robust penile response to all the erotic films than did the low scorers, regardless of the comparative violence or charm of the material viewed.

More intriguing still were the divergent sexual responses between men who ranked high on the inhibition scale and those who scored low. Whereas both groups reacted to the nonthreatening sex scenes with an equivalently hearty degree of tumescence, only the low scorers — those whose answers to the questionnaire indicated they had scant sexual inhibition — maintained an enthusiastic physiological response when confronted with film clips of sexual brutality.

The results suggest that having a good set of sexual brakes not only dampens the willingness to commit rape or sexual abuse, but the desire as well, giving the lie to notions that “all men are the same” and would be likely to rape their way through the local maiden population if they thought they could get away with it.

The researchers have also found a link between sexual inhibition and sexual risk-taking: men who are low in inhibition do not necessarily engage in more or kinkier sex than do their high-inhibition counterparts, but the odds are greater that they will forgo condoms if they indulge.

Most of the studies on the autonomy of sexual brakes and accelerators have been done on men, but scientists lately have begun applying the dual-control model to their studies of female sexuality as well. At first they used a slightly modified version of the excitement/inhibition questionnaire that had proved valuable for assessing men, but they soon realized that their menu of sex situations and checklist of physical arousal cues might be missing large swaths of a woman’s sexual persona.

What was the feminine equivalent of an erection anyway? Was it vaginal swelling and lubrication, or something else entirely? Women are generally smaller and less muscular than men. What might the feeling of being physically threatened do to enhance or hamper a woman’s sexual appetite?

“We started putting together focus groups, asking women to tell us the various things that might turn them on and turn them off sexually, and how they know when they’re sexually aroused,” said Stephanie A. Sanders of the Kinsey Institute and Indiana University. “They mentioned a heightened sense of awareness, genital tingling, butterflies in the stomach, increased heart rate and skin sensitivity, muscle tightness. Then we asked them if they thought the female parallel to an erection is genital lubrication, and they said no, no, you can get wet when you’re not aroused, it changes with the menstrual cycle, it’s not a meaningful measure.”

Through the focus groups, Dr. Sanders and her colleagues compiled a new, female-friendly but admittedly cumbersome draft questionnaire that they whittled down into a useful research tool. They asked 655 women, ages 18 to 81, to complete the draft survey and scrutinized the results in search of areas of concurrence and variability.

The researchers have identified a number of dimensions on which their beta testers agreed. For example, 93 to 96 percent of the 655 respondents strongly endorsed statements that linked sexual arousal to “feeling connected to” or “loved by” a partner, and to the belief that the partner is “really interested in me as a person”; they also concurred that they have trouble getting excited when they are “feeling unattractive.”

But women’s tastes varied widely in many of the finer details of seduction and setting. “Some women say they find the male body odor attractive, others repulsive,” Dr. Sanders said. “Some women are turned on by the idea of having sex in an unusual or unconcealed place where they may be caught in the act, while others have a hard time getting aroused if they think others may hear them, or the kids will walk in.”

Conventional wisdom has it that a woman’s libido is stifled by unhappiness, anxiety or anger, but the survey showed that about 25 percent of women used sex to lift them out of a bad mood or to resolve a marital spat.

Women also differed in the importance they accorded a man’s physical appearance, with many expressing a comparatively greater likelihood of being aroused by evidence of talent or intelligence — say, while watching a man deliver a great speech.

The researchers are now trying to correlate women’s sexual inhibition and excitement ratings to their sexual behavior and sexual self-image— whether they are likely to engage in risky sex, dissatisfying sex or no sex at all.

Other scientists have devised surveys of their own to plumb the depths and contours of sexual desire. Richard A. Lippa, a professor of psychology at California State University in Fullerton, for months invited anybody with the time and interest to take his online survey, in which he asked people to rate their reactions to statements like “I frequently think about sex,” “It doesn’t take much to get me sexually excited,” “I fantasize about having sex with men,” “I think a woman’s body is sexy” and “If I were looking through a catalog with sexy swimsuits, I’d spend more time looking at the men in the pictures than the women.” Dr. Lippa has collected responses from more than 200,000 people around the world, and, though he has yet to complete his analysis of the data, a number of salient findings shine through. Whether the test-takers live in North America, Latin America, Britain, Western Europe or Japan, he said, men on average report having a higher sex drive than women, and women prove comparatively more variable in their sex drive.

“Men have a consistently high sex drive,” he said, “while in women you see more low sex drive and more high sex drive.”

Women’s sexual fluidity extends beyond the strength of desire, he said, to encompass the objects of that desire. In his survey, heterosexual women who rated their sex drive as high turned out to have an increased attraction to women as well as to men.

“This is not to say that all women are bisexual,” Dr. Lippa said. “Most of the heterosexual women would still describe themselves as more attracted to men than to women.” Still, the mere presence of a hearty sexual appetite seemed to expand a heterosexual woman’s appreciation of her fellow women’s forms. By contrast, the men were more black-and-white in their predilections. If they were straight and had an especially high sex drive, that concupiscence applied only to women; if gay, to other men.

Dr. Diamond of the University of Utah also has evidence that women’s sexual attractions are, as she put it, “more nonexclusive than men’s.”

One factor that may contribute to women’s sexual ambidextrousness, some researchers suggest, is the intriguing and poorly understood nonspecificity of women’s physical reactions to sexual stimuli. As Dr. Chivers of the Center for Addiction and Mental Health and other researchers have found, women and men show very divergent patterns of genital arousal while viewing material with sexual content.

For men, there is a strong concordance between their physiological and psychological states. If they are looking at images that they describe as sexually arousing, they get erections. When the images are not to their expressed taste or sexual orientation, however, their genitals remain unmoved.

For women, the correlation between pelvic and psychic excitement is virtually nil. Women’s genitals, it seems, respond to all sex, all the time. Show a woman scenes of a man and a woman having sex, or two women having sex, or two men, or even two bonobos, Dr. Chivers said, and as a rule her genitals will become measurably congested and lubricated, although in many cases she may not be aware of the response.

Ask her what she thinks of the material viewed, however, and she will firmly declare that she liked this scene, found that one repellent, and, frankly, the chimpanzee bit didn’t do it for her at all. Regardless of declared sexual orientation, Dr. Chivers said, “with women, there’s a discrepancy between stated preference and physiological arousal, and this discrepancy has been seen consistently across studies.”

Again, the why of it remains a mystery. Dr. Chivers and others have hypothesized that the mechanism is protective. Women are ever in danger of being raped, they said, and by automatically lubricating at the mere hint of sex, they may avoid damage during forced intercourse to that evolutionarily all-important reproductive tract.

Regardless of gender or relative genital congestion, people attend almost reflexively to sexual imagery. In an effort to trace that response back to the body’s premier sex organ, Kim Wallen and his colleagues at Emory University in Atlanta have performed brain scans on volunteers as the subjects viewed a series of sexually explicit photographs. The researchers discovered that men’s and women’s brains reacted differently to the images. Most notably, men showed far more activity than women did in the amygdala, the almond-contoured brain sector long associated with powerful emotions like fear and anger rather than with anything erotic.

Heather Rupp, a graduate student in Dr. Wallen’s lab, tried to determine whether the divergent brain responses were a result of divergent appraisals, of men and women focusing on different parts of the same photographs. “We hypothesized, based on common lore, that women would look at faces, and men at genitals,” Dr. Wallen said. But on tracking the eye movements of study participants as they sized up erotic photographs, Ms. Rupp dashed those prior assumptions. “The big surprise was that men looked at the faces much more than women did,” Dr. Wallen said, “and both looked at the genitals comparably.”

The researchers had also predicted that men would be more drawn than women to close-up views of genitalia, but it turned out that everybody flipped past them as quickly as possible. Women lingered longer and with greater stated enjoyment than did their male counterparts on photographs of men performing oral sex on women; and they noticed more fashion details. “We got spontaneous reports from the women that we never got from the males, comments like ‘I would have liked the photos better if the people didn’t have those ridiculous ‘70s hairstyles,’ ” Dr. Wallen said.

He proposes that one reason men would scrutinize faces in pornographic imagery is that a man often looks to a woman’s face for cues to her level of sexual arousal, since her body, unlike a man’s, does not give her away.

Some researchers say that on average, male sexual desire is not only stronger than women’s, but also more constant from hour to hour, day to day. They point to a significant body of research suggesting a certain cyclic nature to female desire, and some say women only begin to attain masculine heights of lustiness during the few days of the month that they are fertile.

Studies have indicated, for example, that women are likelier to fantasize about sex, masturbate, initiate sex with their mates, wear provocative clothing and frequent singles bars right around ovulation than at any other time of the month. Women obviously can, and do, have sex outside their window of reproductive opportunity, but it makes good Darwinian sense, Dr. Wallen said, for them to have some extra oomph while they are fertile.

Men, by contrast, are generally fecund all month long, and they are theoretically ever anxious to share that bounty with others, a state of perpetual readiness that Roy F. Baumeister, a psychology professor at Florida State University, described as “the tragedy of the male sex drive.”

Yet some experts argue that such absolutist formulas neglect the importance of age, experience, culture and circumstance in determining the strength of any individual’s sexual desire.

“Baumeister’s ideas may have some validity for people in nonmarried relationships who are under the age of 40,” said Barry W. McCarthy, a sex therapist in Washington and one of the venerable voices in the field. “But as men and women age, they become much more alike in so many ways, including in their sexual desire.”

For women, Dr. McCarthy said, “sex feels more in their control and safer for them,” while the aging man loses the need to imagine himself the “sexual master of the universe.”

As one married male photographer and editor in his mid-50s said, “Jeez, when I was 20, I couldn’t walk straight,” but now he is sexually much looser and “unconcerned.” And while he considers his libido to be of standard dimensions for men his age, he also said it “exactly matches that of my partner.” Together they walk the line.

Desire between the sexes is not a matter of choice. Straight men, it seems, have neural circuits that prompt them to seek out women; gay men have those prompting them to seek other men. Women’s brains may be organized to select men who seem likely to provide for them and their children. The deal is sealed with other neural programs that induce a burst of romantic love, followed by long-term attachment.

So much fuss, so intricate a dance, all to achieve success on the simple scale that is all evolution cares about, that of raisingthe greatest number of children to adulthood. Desire may seem the core of human sexual behavior, but it is just the central act in a long drama whose script is written quite substantially in the genes.

In the womb, the body of a developing fetus is female by default and becomes male if the male-determining gene known as SRY is present. This dominant gene, the Y chromosome’s proudest and almost only possession, sidetracks the reproductive tissue from its ovarian fate and switches it into becoming testes. Hormones from the testes, chiefly testosterone, mold the body into male form.

In puberty, the reproductive systems are primed for action by the brain. Amazing electrical machine that it may be, the brain can also behave like a humble gland. In the hypothalamus, at the central base of the brain, lie a cluster of about 2,000 neurons that ignite puberty when they start to secrete pulses of gonadotropin-releasing hormone, which sets off a cascade of other hormones.

The trigger that stirs these neurons is still unknown, but probably the brain monitors internal signals as to whether the body is ready to reproduce and external cues as to whether circumstances are propitious for yielding to desire.

Several advances in the last decade have underlined the bizarre fact that the brain is a full-fledged sexual organ, in that the two sexes have profoundly different versions of it. This is the handiwork of testosterone, which masculinizes the brain as thoroughly as it does the rest of the body.

It is a misconception that the differences between men’s and women’s brains are small or erratic or found only in a few extreme cases, Dr. Larry Cahill of the University of California, Irvine, wrote last year in Nature Reviews Neuroscience. Widespread regions of the cortex, the brain’s outer layer that performs much of its higher-level processing, are thicker in women. The hippocampus, where initial memories are formed, occupies a larger fraction of the female brain.

Techniques for imaging the brain have begun to show that men and women use their brains in different ways even when doing the same thing. In the case of the amygdala, a pair of organs that helps prioritize memories according to their emotional strength, women use the left amygdala for this purpose but men tend to use the right.

It is no surprise that the male and female versions of the human brain operate in distinct patterns, despite the heavy influence of culture. The male brain is sexually oriented toward women as an object of desire. The most direct evidence comes from a handful of cases, some of them circumcision accidents, in which boy babies have lost their penises and been reared as female. Despite every social inducement to the opposite, they grow up desiring women as partners, not men.

“If you can’t make a male attracted to other males by cutting off his penis, how strong could any psychosocial effect be?” said J. Michael Bailey, an expert on sexual orientation at Northwestern University.

Presumably the masculinization of the brain shapes some neural circuit that makes women desirable. If so, this circuitry is wired differently in gay men. In experiments in which subjects are shown photographs of desirable men or women, straight men are aroused by women, gay men by men.

Such experiments do not show the same clear divide with women. Whether women describe themselves as straight or lesbian, “Their sexual arousal seems to be relatively indiscriminate — they get aroused by both male and female images,” Dr. Bailey said. “I’m not even sure females have a sexual orientation. But they have sexual preferences. Women are very picky, and most choose to have sex with men.”

Dr. Bailey believes that the systems for sexual orientation and arousal make men go out and find people to have sex with, whereas women are more focused on accepting or rejecting those who seek sex with them.

Similar differences between the sexes are seen by Marc Breedlove, a neuroscientist at Michigan State University. “Most males are quite stubborn in their ideas about which sex they want to pursue, while women seem more flexible,” he said.

Sexual orientation, at least for men, seems to be settled before birth. “I think most of the scientists working on these questions are convinced that the antecedents of sexual orientation in males are happening early in life, probably before birth,” Dr. Breedlove said, “whereas for females, some are probably born to become gay, but clearly some get there quite late in life.”

Sexual behavior includes a lot more than sex. Helen Fisher, an anthropologist at Rutgers University, argues that three primary brain systems have evolved to direct reproductive behavior. One is the sex drive that motivates people to seek partners. A second is a program for romantic attraction that makes people fixate on specific partners. Third is a mechanism for long-term attachment that induces people to stay together long enough to complete their parental duties.

Romantic love, which in its intense early stage “can last 12-18 months,” is a universal human phenomenon, Dr. Fisher wrote last year in The Proceedings of the Royal Society, and is likely to be a built-in feature of the brain. Brain imaging studies show that a particular area of the brain, one associated with the reward system, is activated when subjects contemplate a photo of their lover.

The best evidence for a long-term attachment process in mammals comes from studies of voles, a small mouselike rodent. A hormone called vasopressin, which is active in the brain, leads some voles to stay pair-bonded for life. People possess the same hormone, suggesting a similar mechanism could be at work in humans, though this has yet to be proved.

Researchers have devoted considerable effort to understanding homosexuality in men and women, both for its intrinsic interest and for the light it could shed on the more usual channels of desire. Studies of twins show that homosexuality, especially among men, is quite heritable, meaning there is a genetic component to it. But since gay men have about one-fifth as many children as straight men, any gene favoring homosexuality should quickly disappear from the population.

Such genes could be retained if gay men were unusually effective protectors of their nephews and nieces, helping genes just like theirs get into future generations. But gay men make no better uncles than straight men, according to a study by Dr. Bailey. So that leaves the possibility that being gay is a byproduct of a gene that persists because it enhances fertility in other family members. Some studies have found that gay men have more relatives than straight men, particularly on their mother’s side.

But Dr. Bailey believes the effect, if real, would be more clear-cut. “Male homosexuality is evolutionarily maladaptive,” he said, noting that the phrase means only that genes favoring homosexuality cannot be favored by evolution if fewer such genes reach the next generation.

A somewhat more straightforward clue to the origin of homosexuality is the fraternal birth order effect. Two Canadian researchers, Ray Blanchard and Anthony F. Bogaert, have shown that having older brothers substantially increases the chances that a man will be gay. Older sisters don’t count, nor does it matter whether the brothers are in the house when the boy is reared.

The finding suggests that male homosexuality in these cases is caused by some event in the womb, such as “a maternal immune response to succeeding male pregnancies,” Dr. Bogaert wrote last year in the Proceedings of the National Academy of Sciences. Antimale antibodies could perhaps interfere with the usual masculinization of the brain that occurs before birth, though no such antibodies have yet been detected.

The fraternal birth order effect is quite substantial. Some 15 percent of gay men can attribute their homosexuality to it, based on the assumption that 1 percent to 4 percent of men are gay, and each additional older brother increases the odds of same-sex attraction by 33 percent.

The effect supports the idea that the levels of circulating testosterone before birth are critical in determining sexual orientation. But testosterone in the fetus cannot be measured, and as adults, gay and straight men have the same levels of the hormone, giving no clue to prenatal exposure. So the hypothesis, though plausible, has not been proved.

A significant recent advance in understanding the basis of sexuality and desire has been the discovery that genes may have a direct effect on the sexual differentiation of the brain. Researchers had long assumed that steroid hormones like testosterone and estrogen did all the heavy lifting of shaping the male and female brains. But Arthur Arnold of the University of California, Los Angeles, has found that male and female neurons behave somewhat differently when kept in laboratory glassware. And last year Eric Vilain, also of U.C.L.A., made the surprising finding that the SRY gene is active in certain cells of the brain, at least in mice. Its brain role is quite different from its testosterone-related activities, and women’s neurons presumably perform that role by other means.

It so happens that an unusually large number of brain-related genes are situated on the X chromosome. The sudden emergence of the X and Y chromosomes in brain function has caught the attention of evolutionary biologists. Since men have only one X chromosome, natural selection can speedily promote any advantageous mutation that arises in one of the X’s genes. So if those picky women should be looking for smartness in prospective male partners, that might explain why so many brain-related genes ended up on the X.

“It’s popular among male academics to say that females preferred smarter guys,” Dr. Arnold said. “Such genes will be quickly selected in males because new beneficial mutations will be quickly apparent.”

Several profound consequences follow from the fact that men have only one copy of the many X-related brain genes and women two. One is that many neurological diseases are more common in men because women are unlikely to suffer mutations in both copies of a gene.

Another is that men, as a group, “will have more variable brain phenotypes,” Dr. Arnold writes, because women’s second copy of every gene dampens the effects of mutations that arise in the other.

Greater male variance means that although average IQ is identical in men and women, there are fewer average men and more at both extremes. Women’s care in selecting mates, combined with the fast selection made possible by men’s lack of backup copies of X-related genes, may have driven the divergence between male and female brains. The same factors could explain, some researchers believe, why the human brain has tripled in volume over just the last 2.5 million years.

Who can doubt it? It is indeed desire that makes the world go round.

This June, Harper Collins will publish her latest work, a personal meditation about sex and aging, “Prime: Adventures and Advice on Sex, Love and the Sensual Years.”

If Dr. Schwartz, 61, is able to bridge the chasm between academe and the airport newsstand, that is because she specializes in a subject the entire world cares about. (Think Carrie Bradshaw with a doctorate.)

“I always wanted to study matters that were important to people in their everyday lives,” she said one recent morning, “and frankly, what’s more basic than sexuality?”

Q. How did you become a sociologist of sex?

A. I was a graduate student at Yale in the late 1960s, studying the sociology of law. At the time, women were not accepted as undergraduates. But in 1969, a decision was made to finally admit them. With such huge changes happening all around me, I found myself more drawn to the sociology of gender than law.

So I signed up to be a teaching assistant in a class on sexuality — one of the first offered to undergraduates since Kinsey’s time. Some of the reading assigned to the students made me nuts. There was all this double-standard stuff about “bad girls” and “good girls.”

When I scanned the professional literature for alternatives, I couldn’t find much. I thought: “I have to deal with this. This is an area I need to contribute to.”

Q. At the time, was the sociology of sex considered a serious area for study?

A. Not really. Many of the earlier sex researchers had been medical doctors. For the most part, they looked at sex from a biological standpoint. The other stream was the Kinsey thing, which was more an enumeration of sexual acts, but not necessarily meanings — as if all acts were the same as one another.

Two researchers I found inspiring were William Simon and John H. Gagnon. They were sociologists. And they believed that to understand sexuality you had to look at how institutions impacted it, that you couldn’t separate behavior from a cultural context. People now accept that. But those were new ideas then.

Q. How has your field changed over the decades?

A. For one thing, studying sexuality has become more acceptable. Back then, it was like if you studied sexuality, it meant you had a sexual problem. Everyone thought there’d have to be some bizarre reason why you’d studied it.

Another thing: there’s more money for research now. Research into sexuality had been poorly funded. But in the 1980s with H.I.V./AIDS, there was, suddenly, money. Epidemiologists understood that you couldn’t contain AIDS without understanding why people engaged in certain practices, why they took risks.

What didn’t change much was the difficulty of finding governmental money to study pleasure. If you wanted to discover why some women didn’t have orgasms, for instance, you were likely to have a tough time finding funding.

Q. Is that still true?

A. Yes and no. There’s a lot of pharmaceutical money now in sex research. Viagra. Once Viagra earned millions of dollars, the pharmaceutical companies saw how sexual pleasure could be monetized. I think the industry discovered there was a longing for sexual performance throughout the culture.

Viagra could work for some men because, for them, the ability to have performance created desire. The companies wanted to find something similar for women. For most women, however, sex wasn’t a performance issue. Female sexuality is more complicated. So the drug companies funded many large studies into desire in both men and women. They’ve created much new literature and new professional societies to meet and discuss it.

And there’s a big debate right now in the research professions. Should we take pharmaceutical money? A lot of the companies will not let you publish negative findings. It’s not ideal research conditions to take money from someone who has a stake in the outcome.

Q. What’s your view?

A. That the drug companies have pumped a huge amount of money into questions not funded by the government. I can understand why a researcher might accept it.

Q. You are a co-author of the 1983 study “American Couples: Money, Work, Sex.” Why do proponents of same-sex marriage frequently cite it?

A. The late Philip Blumstein and I sampled 12,000 people. We compared intimacy in four types of couples: heterosexual marrieds, cohabitating heterosexuals, same-sex males and lesbians. The surprising thing we found was that the straight married couples and the gay and lesbian couples had far more in common with each other than the straight cohabitators.

We saw that the institutional power of marriage makes a big difference. From that, we recommended that gay people ought to have the right to be married.

Q. Today you teach a course for 700 undergraduates at the University of Washington — the sociology of sex. Are your students different from your college peers in the 1960s?

A. So different. They are sexually active and they are not as moralistic. To be a nonvirgin when I was starting out was suspect and usually stigmatized. To be a virgin now is suspect and stigmatized.

What I find telling is that about half my students had abstinence education in high school, and yet they are active. In class, they seem hungry for good information. They want to know about technique, about being good partners. The girls are out there as much as the boys. They ask forthright questions that would have embarrassed my peers. This openness is pleasing. It’s also something I couldn’t have imagined 40 years ago.

In fact, it is rarely age per se that accounts for declines in libido among those in the second half-century of life. Rather, it can be any of a dozen or more factors more common in older people that account for the changes. Many of these factors are subject to modification that can restore, if not the sexual energy of youth, at least the desire to seek and the ability to enjoy sex.

Nor is it just hormones. Addressing only the distaff half of the population, the Boston Women’s Health Book Collective, in its newest work, “Our Bodies, Ourselves: Menopause,” points out: “Our sexual desire and satisfaction may be influenced by our life circumstances, including the quality of our sexual relationships, our emotional and physical health, and our values and thoughts about sexuality, as well as by the aging process and the shifting hormone levels that occur during the menopause transition.”

The same, of course, is true of men. Difficult life circumstances can do much to dampen anyone’s libido. Stress at work or home, looming bankruptcy, impending divorce, serious illness, depression, a history of sexual abuse and a host of medications are among the many things that can put a big crimp in your desire for sex at any age.

Feel Attractive, Be Attractive

As people age, both physical and emotional changes occur that can influence libido. Wrinkles, hair loss, declining muscle mass and accumulation of body fat, among other age-related changes, can make men and women feel less attractive. And if you don’t see yourself as attractive, your brain may respond by dampening any impulse you might have to be intimate with someone.

I have no studies to corroborate this idea, but I strongly suspect that older people who stay in shape physically, keep their brains stimulated and remain interested in a variety of activities are likely to feel more attractive and be more attractive — and thus more libidinous — than those who let themselves go to pot, as it were. I’m not suggesting that people in their 60s and 70s start dressing and acting like 20-somethings, but there are any number of age-appropriate actions that can help people see themselves — and help others see them — as sexually desirable beings.

Of course, illness, both mental and physical, can seriously disrupt a healthy libido at any age. Diseases of the adrenal, pituitary or thyroid glands can diminish sexual desire, as can depression and anxiety. Likewise, several common cancers — especially cancers of the breast, testes or prostate or the drugs used to treat them — may suppress the desire for sex.

Many commonly administered medications can interfere with sexual desire, performance or both. Among the most frequent offenders are antidepressants and antianxiety drugs, blood pressure medications and opioid pain relievers. High doses of alcohol likewise blunt desire as well as performance. Even drugs taken to curb heartburn can curb the desire for sex. In some instances, changing the dose, switching to a different drug or taking a brief drug holiday (say, for the weekend) can boost libido.

A Change of Scene

While a drug like Viagra may help a man temporarily overcome disease- or medication-induced erectile dysfunction, it does nothing to increase desire, which is essential for these potency-enhancing drugs to work.

Knowing how to please each other sustains sexual interest for many long-established couples. But for others, familiarity can breed boredom; they lose interest in doing the same old thing the same old way time after time.

Novelty is a well-established sexual stimulant. An unattached man or woman in midlife or beyond who had all but forgotten about sex meets someone new and attractive, and suddenly the flames of sex are reignited. This can happen, too, to very old people. Stories abound in assisted living and nursing home facilities of elderly widows and widowers whose long-dormant sexuality is reawakened by attraction to a new, albeit equally old, partner.

Of course, changing partners is not a realistic option for those in a long-standing monogamous relationship in which sexual intimacy is just a fond memory.

But there are ways for such couples to introduce novelty — ranging from a change of venue or techniques to an exchange of fantasies or even the introduction of sex toys — that may rekindle sexual feelings.

Even young couples can find their interest in sex diminished by a fear of interruption or being overheard by children or an elderly parent. It can take some effort — and perhaps a lock on the bedroom door and background music — to reduce the risk of distractions that blunt the flame of desire.

Women may think that the decline in estrogen at menopause is responsible for their loss of interest in sex. But estrogen loss is only an indirect factor; it can result in vaginal tightness and dryness that renders intercourse painful rather than pleasurable. The use of lubricants and a dildo or more frequent sex can often counteract these effects. But for some women, the use of a vaginal estrogen cream or suppository is necessary to make sex comfortable and more desirable.

The Testosterone Factor

But the real libido hormone, for both men and women, is testosterone, which women produce in their ovaries and adrenal glands. As other ovarian hormone levels drop after menopause or surgical removal of the ovaries, so does the amount of desire-boosting testosterone. This has prompted some women to use testosterone replacement therapy to get their sex lives back on track. One drug commonly prescribed off-label is Estratest, a combination of small doses of estrogen and testosterone. Some doctors tailor-make low-dose testosterone preparations for women. A testosterone patch for women has not been approved by the Food and Drug Administration because of insufficient safety data.

Women taking testosterone should be carefully monitored, because safe levels of the hormone for women have not been determined. Common side effects include unwanted hair growth and a deepening of the voice. Women who have had breast or uterine cancer or diseases of the liver or heart should avoid testosterone replacement.

Sexual desire among men, too, can be squelched by low levels of testosterone. While there is no official recognition of male menopause, men experience declining levels of hormones as they age — what some experts called andropause — that can affect sexual desire and performance. Other symptoms of this deficiency may include enlarged breasts, loss of body or facial hair, and osteoporosis before age 65.

Testosterone replacement is helpful in restoring the sex drive only of men who have low levels of the hormone. A test of testosterone levels should be done and other causes (besides age) should be ruled out before the hormone is prescribed. Risks include prostate enlargement and prostate cancer.

She was right to be suspicious. Her ex had hacked into her e-mail account, either guessing her password or using spyware -- software that can secretly read e-mails and survey cyber-traffic, law enforcement officials said. For months, apparently, he had followed her every online move, part of a pattern of abuse city police are still investigating.

Law enforcement officials and safety groups have focused on the Internet as an arena for such types of harassment as false impersonation and character assassination as more people voluntarily place their private lives on public display through Web sites such as Facebook.com and MySpace.com.

But a little-discussed and more threatening phenomenon is also happening to the unwitting online and in the high-tech world: cyber-stalking, the illegal monitoring of private information and communication of ex-lovers and spouses as a form of domestic violence. The spurned often use global positioning systems, invasive computer programs, cellphone monitoring chips and tiny cameras to follow the whereabouts, goings-on and personal communications of unsuspecting victims.

Cases from across the country have shown that stalkers with little more than cursory computer knowledge have been able to track the e-mail and Web activity of current or recently divorced spouses. In other cases, some cellphones, outfitted with GPS chips, are secretly attached to cars, and the signals are then followed online.

A Fairfax County woman named Carol, who requested that her last name be withheld because her case is ongoing, said her ex-husband accessed her e-mail and confronted her with personal information she had shared only with a close family member.

The cyber-stalking came after weeks of harassing e-mails and traditional stalking behavior, such as peeking in her window. She's convinced that he presented the computer information to prove that he could violate her sense of security whenever and wherever he wanted, even after he moved out of the region. At one point he sent an e-mail saying "I know what you're doing" and recounted personal actions she had told a family member only via e-mail.

"When the stalking comes from someplace, anyplace, it makes you wonder what he's really capable of . . . what he was going to do next," Carol said. "He could have been anywhere at anytime looking into my life and getting to me. He could have seen anything, like legal documents I was forwarding; or where I was going to be. That's what I never knew."

Just as technology has opened a new realm of abuse to those who seek to stalk someone from afar, cyber-stalking, in turn, has opened a new avenue of violation. Victims feel powerless to stop others from reading legal documents and intimate correspondence as well as tracking their every online move.

"What's so disturbing for many victims is that they can be harassed or followed from anywhere," said Susan Folwell, manager of the Domestic Violence Grant Program at the Women's Center, a counseling and resource center in Vienna. She said she has worked with victims who have had GPS devices placed in children's backpacks and listening devices put in tote bags.

"Victims begin thinking, 'I'm totally powerless' and start wondering what they have to give up to stay safe," she added.

The scope of the activity is somewhat unclear, police officials and victims' rights advocates said. In many cases, those who are being stalked through the airwaves aren't aware that they are being monitored. And evidence is difficult to gather, so police officials often don't feel they have enough to clinch prosecution.

"When a victim first talks to the police, the stalker's behavior may not necessarily look all that dangerous to an outsider," said Cindy Southworth, director of the Safety Net Project, a program run by the National Network to End Domestic Violence, an advocacy group in Washington. Cyber-stalking is the topic of a national conference this month in New Orleans.

"But when you look deeper at the pattern of stalking . . . following, calling and showing up unannounced someplace time and time again to track a victim, it becomes clear that these cyber and non-cyber tactics are designed to induce fear," she said.

With the technology rapidly becoming cheaper and more readily available, police departments, prosecutors and advocates who work with domestic violence victims are struggling to keep up.

"It seems like these stalkers are a step ahead of us," said Amy Santiago, a detective with the Alexandria Police Department's domestic violence unit, which has investigated about a dozen cases. "We're trying to keep up with it, but it seems like every day things are changing."

Victims and advocates said the 21st-century stalking has taken the repeated phone calls in the middle of the night to an entirely new level. A Prince William County woman, who asked that her name be withheld because she feared retribution from her ex-husband, said the cyber-stalking she experienced in early 2006 at his hands shook her even when she knew he was not in the area.

"He would show up to places that I had only told people in e-mails . . . my lawyer's office," the woman said. "I'd sit there and think: How did he know I was going to be here? How? I felt like I was going crazy."

She added that in one situation, she and her ex-husband began shouting when he showed up at the attorney's office, and the quarrel turned into a brief shoving match in front of their daughter. She said that even though she knows he left the area in 2005, she checked her car once a week for GPS devices until late last year.

Generally, the Web-based technology used is spyware -- software that allows stalkers to invade their victims' computers by sending an e-mail. When the e-mail is opened, the spyware secretly latches onto the target. Personal information, as well as keystrokes and a user's Web-browsing history, can be stolen. Documents on hard disks can be scanned.

Stalkers also use GPS devices, on their own or as chips in cellphones. The units can be traced online to track the whereabouts of targets. To keep the systems running, sophisticated stalkers have attached the devices to power sources in cars.

It's not hard to figure out. Do-it-yourself manuals are widely available online. Some sites advertise otherwise legitimate programs for stalking uses. For instance, spyware was developed commercially to help parents keep tabs on their children's Web use and to provide information for advertisers. Now it is commonly advertised on Web sites as a way to snoop on a spouse. "Monitor any PC from anywhere!" one ad promises. "Spy stealthily so that the user won't know such monitoring exists," another says.

State legislatures took notice of online abuse about 2000 and began passing laws that make high-tech stalking a crime. A law President Bush signed last year also prohibits anonymous electronic communications intended to "threaten, abuse and harass." In addition, the Bureau of Justice Statistics has started to track technological methods used in stalking and domestic violence.

Nonetheless, advocates note that legislation might not help because it could limit the ability of authorities to counteract yet-to-be-developed technologies.

To catch up to the criminals, police domestic violence units are being trained to deal with the increasing use of technology and are beginning to ask potential victims whether they suspect that the privacy of their online activity has been violated.

In addition, lawyers who specialize in such cases are beginning to advise clients to be careful how they communicate through computers, to change passwords frequently and to hand-deliver important documents if they are going through difficult marital separation proceedings.

"This happens more frequently than people realize. . . . It's like a virus," said Mehagen McRae, a Fairfax lawyer who said she worked on a spate of such cases in 2005 and 2006. "I tell my clients to act as if the entire world is reading their e-mails and that if they feel as if they are being watched, they are probably right."

Drug Eases Vets' Stress Symptoms
Chicago Tribune, 4/14/2007

TEXAS -- A widely used hypertension drug improves sleep and reduces traumatic nightmares in veterans with post-traumatic stress disorder, federal researchers say. "This is the first drug that has been demonstrated effective for PTSD nightmares and sleep disruption," said Dr. Murray Raskind of the Veterans Affairs Puget Sound Health Care System, who led the study. "These nightmares are heavily troublesome to veterans," he said. He estimated that as many as half of the 10 million U.S. veterans and civilians with PTSD had nightmares that could be helped by the drug. At least 5,000 veterans in the VA system in the Northwest are receiving the generic drug, called prazosin, he said.
     Raskind and his colleagues enrolled 40 veterans; half received the drug and half took a placebo for eight weeks. The researchers are reporting their findings Saturday in the journal Biological Psychiatry. Three larger studies of the drug are beginning or under way.