Monday, February 26, 2007

Study Shows Link Between Early Sex & Delinquency

Teens who start having sex significantly earlier than their peers also show higher rates of delinquency in later years, new research shows.

A national study of more than 7,000 youth found that adolescents who had sex early showed a 20 percent increase in delinquent acts one year later compared to those whose first sexual experience occurred at the average age for their school.

In contrast, those teens who waited longer than average to have sex had delinquency rates 50 percent lower a year later compared to average teens. And those trends continued up to six years.

"We're not finding that sex itself leads to delinquency, but instead, that beginning sexual relationships long before your friends is cause for concern," said Stacy Armour, co-author of the study and a doctoral student in sociology at Ohio State University.

Armour conducted the study with Dana Haynie, associate professor of sociology at Ohio State. Their results appear in the February 2007 issue of the Journal of Youth and Adolescence.

"The findings point out the importance of acting within normal bounds for your age group," Haynie said. "Those who start having sex too young may not be prepared to deal with the potential emotional, social and behavioral consequences of their actions."

The researchers used data from the National Longitudinal Study of Adolescent Health. An initial survey was conducted in 1994-95 of students from across the country in grades 7 to 12. These students attended 132 high schools and their "feeder" middle schools.

This study included students who reported they were virgins in this first survey. They were then surveyed again one year later, and a third time six years later in 2002.

In this study, the average age of sexual debut -- age at first intercourse -- was calculated for each school in the sample.

"That way, the respondents in the study are compared to the peers in their own school, rather than an arbitrary age that is deemed the average age for everyone," Armour said.

The average age for sexual debut in this study ranged from 11.25 to 17.5 years of age, depending on the individual schools.

Adolescents in the sample who had their first sexual encounter about one year or more before average for their school (the exact length differed for each school) were considered early.

To determine rates of delinquency, students in the survey were asked how often in the past year they participated in a variety of delinquent acts, including painting graffiti, deliberately damaging property, stealing, or selling drugs.

The study found that youth who had their sexual debut between the first and second surveys showed a 58 percent increase in delinquency compared to those who remained virgins. But the increases were more pronounced for those who were younger than their peers when they first had sex.

The researchers found that of those respondents who had their first sexual experience between the first and second surveys, 9 percent had started significantly earlier than their peers, 58 percent were average, and 33 percent experienced sexual intercourse significantly later than others.

The researchers took into account a variety of factors that could affect how long adolescents wait to have sex, including race, family structure, socioeconomic status, school performance, depression, how close the teens felt to their parents, and other factors.

Armour said the link between early sex and delinquency probably has to do with the whole social context of the young adolescents' lives.

"If you're having sex a lot earlier than your friends, you may be hanging out with a new group of kids, ones who are probably older," Armour said.

"Having sex brings with it this feeling of being an adult. They may feel like they can do things older kids do, and for some that may include delinquency."

And these negative effects of early sex may last through adolescence and into early adulthood.

When the same respondents were surveyed again in 2002 -- when most were between the ages of 18 and 26 -- results showed that the age of first sex was still associated with levels of delinquency.

"The timing of events such as sexual activity can have profound consequences for adolescents, particularly when they occur prematurely," Armour said.

On the other hand, delaying sex can have positive effects for adolescents.

"Those adolescents who waited longer than average may be developing friendships and relationships that can help protect them from potentially troublesome behaviors as they become young adults," she said.

"Sex itself is not always a problem behavior," Armour explained. "But the timing of sexual initiation does matter. Adolescents need to be at a stage when they are developmentally prepared for it."

Friday, February 23, 2007

New Measure of Sexual Arousal Found for Both Men and Women

Temperature Changes Measured by Thermography During Sexual Arousal Demonstrate Similar Patterns of Temperature Increases Specific to the Genital Regions

According to a new study published in the latest issue of The Journal of Sexual Medicine and conducted in the Department of Psychology of McGill University, thermography shows great promise as a diagnostic method of measuring sexual arousal. It is less intrusive than currently utilized methods, and is the only available test that requires no physical contact with participants. Thermography is currently the only method that can be used to diagnose sexual health problems in both women and men. In fact, women and men demonstrated similar patterns of temperature change during sexual arousal with no significant differences between genders in the time needed to reach peak temperature.

“Using thermography, we also found that women’s subjective experience of sexual arousal corresponded with their physiological genital response; this challenges the common notion that women don’t know their bodies,” says Tuuli Kukkonen, a Ph.D. candidate in psychology at McGill University and lead author of the study.

“I predict that the major physiological measure of sexual arousal for most future clinical trials of female sexual arousal disorder will be genital temperature as measured by thermography,” according to Dr. Yitzchak Binik, senior author of the research and Professor of Psychology at McGill and Director of the Sex and Couple Therapy Service of the McGill University Health Center (

“This is a huge breakthrough in the assessment of genital blood flow research in women’s sexual health,” observed Irwin Goldstein, Editor-in-Chief of The Journal of Sexual Medicine. "Previous testing was invasive and involved placement of measuring instruments in various locations in the genital region and this interfered with the arousal itself. Thermography does not have any such requirements and is very user-friendly. This may be the first test to diagnose blood vessel blockage as a cause of sexual dysfunction in women, and may help identify those patients who may be helped by vasoactive drugs similar to those prescribed for men with erectile dysfunction from narrowed blood vessels.”

Monday, February 12, 2007

Romance, schmomance -- Natural selection continues even after sex

Some breaking news, just in time for Valentine's Day: Researchers have identified something called "sperm competition" that they think has evolved to ensure a genetic future. In sexual reproduction, natural selection is generally thought of as something that happens prior to – and in fact leads to -- the Big Event. This thinking holds, for example, that we are drawn to physical features that tell us our partner is healthy and will give us a fighting chance to carry on our genetic lineage. But a new article in the February issue of Current Directions in Psychological Science suggests that the human male has evolved mechanisms to pass on his genes during post-copulation as well, a phenomenon dubbed "sperm competition."

In their article, Todd Shackelford and Aaron Goetz at Florida Atlantic University describe this as "the inevitable consequence of males competing for fertilizations."

How much more romantic can you get?

For a monogamous species, sperm competition may seem beside the point. But according to the authors, extra curricular copulations (i.e. affairs) appear to be a significant part of our ancestral history and could, evolutionarily speaking, spell disaster. A male whose female partner engages in some off-line dalliances unwittingly may be investing his resources – food, protection, credit rating -- in a genetically unrelated offspring.

Competition may also affect sperm count, say the authors. The more time men spend away from their partners (time that their partners could have spent with other males), the number of sperm in their ejaculate increases upon their next copulation. In one study, the authors note, artificial phalluses constructed to resemble the structure and function of the human penis actually removed an ejaculate-like substance from an artificial vagina. This could indicate that the penis acts as an anatomical squeegee to remove an interloper's calling card.

But sperm competition is not just biology. According to the authors, many sexual behaviors such as deep copulatory thrusting may function to remove rival sperm. Sexual partners report that men thrust more deeply and quickly into the vagina following allegations of infidelity. The same periods of separation that increase sperm number in male ejaculates may also help to explain the increasingly lustful feelings human males develop after long periods of time apart from their mate. That is, the human male may want to copulate as soon as possible as insurance against possible extra-pair copulation.

These latest findings lead us to wonder about what other undiscovered ways humans have evolved in a world dictated by "survival of the fittest." In fact, the authors compare sexual adaptation to a Cold War phenomenon: "Sexual conflict between males and females," Shackelford and Goetz describe, "produces a coevolutionary arms race between the sexes," in which an advantage gained by one gender leads to counteradaptations in the other. They speculate that research may move beyond male adaptations to, for example, see if females have developed biological or behavioral mechanisms to increase retention of sperm from men with the most favorable genes. But that's for another Valentine's Day.

Friday, February 9, 2007


Think hard and you might recall your first teenage romance. You couldn't sleep or eat -- you couldn't wait to see each other again. You talked on the phone for hours. With Valentine's Day just around the corner, many parents face a challenging balancing act when their teens, just like adults, want to show and express their feelings for their loved ones. Parents want to validate their children's feelings of love and affection while hoping the romance does not include having sex.

"Discussing sexuality issues with teens can be a difficult conversation to have, let alone even initiate," said Catherine Sherwood-Puzzello, a clinical assistant professor in Indiana University Bloomington's Department of Applied Health Science. Her research and teaching interests include human sexuality and public health education. "The best advice is to become an informed and 'askable parent.'"

Parents cringe at having "that" conversation with their children for many reasons. Sherwood-Puzzello offers some tips to help parents and their children open the lines of communication.

* Become informed. Many parents don't know the answers to their teens' questions or they simply don't know how to answer the question. They might feel uncomfortable with the topic, yet fear their teen will get misinformation from other sources. The first step, Sherwood-Puzzello said, is for parents to become informed so fears can be reduced. These Web sites and books can help:;;; Raising a Child Responsibly in a Sexually Permissive World, by Sol Gordon and Judith Gordon (they coined the term "askable parent"), and Did the Sun Shine Before You Were Born, by Judith Gordon, Vivien Cohen and Sol Gordon.

* Be direct about expectations and limitations. These can include such things as curfews, discussions about the appropriate age for dating, and clearly communicating family values about abstinence. This may mean having frequent discussions about the positive aspects of sexual abstinence to reinforce this expected behavior. Sherwood-Puzzello said parents need to be clear about consequences if the expectations are not met. She said parents need to start talking about their expectations and limitations when their children are very young. Young children challenge family rules on a daily basis just to test their parents and to determine whether the rules have changed -- this "challenge" continues into the teen years.

* Be there. Make sure teens know a parent is available to talk. Talking with teens about sexuality will not encourage them to have sex, Sherwood-Puzzello said. It sends the message that someone cares enough to discuss such a sensitive topic and can develop a stronger bond between parent and child.

* Tune in so they don't tune out. Parents need to prepare their responses when the questions are asked. "That's a really good question," is a good first response, Sherwood-Puzzello said, because it allows for the door to stay open and the conversation to continue. Answer only the question the teen asks -- teens will tune parents out when the discussion turns into a lecture, when yelling or shouting begins, or when the parent answers a question with a question. Establishing trust is critical.

* Be a good role model. Parents can be the best person to show appropriate ways their teen can express love and affection. Parents need to be clear about their own sexual attitudes and values. Parents need to discuss their attitudes about love, affection, intimacy and sex with their teens, while at the same time modeling the family values.

* Romance. Parents can steer their children toward healthier and safe ways to show love, such as putting love notes in unexpected places or sending a loving e-mail. Check out the heart graphic with this tip sheet for more ideas.

Wednesday, February 7, 2007

Female Students Play Drinking Games As Much As Males, But Stakes Are Higher

College women may be playing drinking games (i.e. Kings, Beer Pong, Quarters) at rates similar to college men, according to a study led by researchers at Loyola Marymount University. This is the first known study to address a potential increase in undergraduate women’s drinking game participation.

Historically, undergraduate men were thought to drink at higher levels than undergraduate women. Similarly, drinking game participation has traditionally thought to be a male-dominated activity.

However, information collected in this latest study indicated that both male and female college students participate in drinking games regularly and that participation in those games leads to increased consumption of alcohol. Results of the study appeared in the November 2006 issue of Addictive Behaviors journal.

The research also showed that drinking games lead to an increase in women’s binge-drinking (four drinks in a row for females, five drinks in a row for males). Further, in the women, but not the men, playing drinking games was related to more severe negative alcohol-related problems (i.e. missing class, driving under the influence, engaging in unplanned or unprotected sexual activity, etc.)

The study looked at 105 coed college students (35 males and 70 females averaging 18.84 years old) and tracked their drinking and drinking game playing habits for a 3-month period. Participants filled out a questionnaire and then, in one-on-one interviews and with a calendar as a visual aid, recalled their drinking indicating how many drinking events they participated in, how many of those involved drinking games, and how many standard drinks they drank each day, etc. (A standard drink is defined as a drink containing one-half ethyl alcohol—one 12 oz. beer, one 4 oz. glass of wine, or 1.25 oz. shot.)

In those 90 days the male students participated in 469 drinking events and 84 of those events involved drinking games. The female students participated in 915 drinking events and 187 of those involved drinking games. 64 percent of women and 57 percent of men participated in at least one drinking game in the 3-month period. While playing drinking games, men binge-drank 94 percent of the time (averaging 7.95 drinks) and women binge-drank 87 percent of the time (averaging 6.29 drinks).

“Motivation for drinking game participation may differ between men and women students,” said Joseph LaBrie, study author, director of LMU’s Heads Up! program, and professor of psychology at LMU. “Men tend to play drinking games for a variety of social reasons including competitiveness, to intoxicate oneself or others, or to bond with other male players. Our study, along with other recent studies on drinking in college students, suggests that women may be copying the heavy drinking behavior of males often in an effort to gain the esteem of male peers.”

The study –whose participants were 59 percent Caucasian, 15 percent Asian or Pacific Islander, 15 percent Hispanic, 2 percent African American and 9 percent of “mixed” or “other” ethnicity—also indicated that non-Caucasian students were less likely to participate in drinking games and played fewer games than Caucasian students. However, drinking game participation in both women and non-Caucasian participants was related to negative consequences.

“If drinking games are a factor in increased alcohol-related consequences in women and non-Caucasians, then targeted interventions addressing drinking games may be necessary,” said LaBrie. “College health education and student affairs personnel may improve interventions by addressing drinking games and risky drinking.”

This study, co-authored by Eric R. Pedersen and LaBrie, was funded by a grant from the National Institute of Alcohol Abuse and Alcoholism (NIAAA), and is one of many campus-drinking studies conducted by LMU’s Heads Up! program.

Heads Up! seeks to change the campus culture with respect to drinking by involving freshmen, student leaders, faculty, staff, and parents in a comprehensive alcohol awareness and prevention program. The Heads Up! staff works closely with LMU students to create awareness about responsible drinking and thoughtful decision-making through outreach programs and events. For more information on Heads Up!, go to

To read the complete study and other Heads Up! program research papers, go to

Selectivity is ultimate aphrodisiac

Speed daters who romantically desired most of their potential partners were rejected quickly and overwhelmingly, according to a new Northwestern University study.

Conventional wisdom has long taught that one of the best ways to get someone to like you is to make it clear that you like them. Now researchers have discovered that this law of reciprocity is in dire need of an asterisk in the domain of romantic attraction.

The more you tend to experience romantic desire for all the potential romantic partners you meet, the study shows, the less likely it is that they will desire you in return. (Think too desperate, too indiscriminate.)

In contrast, when you desire a potential partner above and beyond your other options, only then is your desire likely to be reciprocated. (Think hallelujah, finally, someone really gets me.)

In the past, social psychologists have had a difficult time observing initial romantic attraction in action, but the speed-dating methodology used in this study allowed the investigators to take a serious look at the chemistry that has been at the center of so much literature, art and imagination throughout the ages.

"Potential partners who seem undiscriminating are a definite turnoff, and those who evoke the magic of feeling special are a big draw," said Paul W. Eastwick, the lead author of the study and a Northwestern graduate student in psychology. "The wild part is that our speed-daters were negotiating all of these subtleties with only four minutes for each date."

"Selective vs. Unselective Romantic Desire: Not All Reciprocity is Created Equal," by Eastwick and Northwestern's Eli J. Finkel, assistant professor of psychology, will be published in the April issue of the journal Psychological Science. Also contributing to the report are Daniel Mochon and Dan Ariely of the Massachusetts Institute of Technology.

"How this all happens is a bit of a mystery," Finkel said. "Put yourself in the position of a speed dater. You're not only able to pick up something about the degree to which that person likes you, but you're able to pick up -- in four minutes -- the degree to which that person likes you more than their other dates. It's amazing."

To explore dynamics in the opening minutes of romantic attraction, the researchers set up seven speed-dating sessions for a total of 156 undergraduate students. Participants had four-minute speed dates with nine to 13 opposite-sex individuals. Immediately following each date, they completed a two-minute questionnaire, answering items such as "I really liked my interaction partner" and "I was sexually attracted to my interaction partner."

After returning home, they recorded on the study Web site whether they would be interested in meeting each person they had speed-dated again in the future. Mutual "yeses" were given the ability to contact one another.

"People who like everyone, unlike in a friendship context where they generally are liked in return, may exude desperation in a romantic context," Finkel said.

"It suggests to us that romantic desire comes in two distinct flavors: selective and unselective," Eastwick added. "If your goal is to get someone to notice you, the unselective flavor is going to fail, and fast."

The need to feel special or unique could be a broad motivation that stretches across our social lives, the study concludes. "Just as this need plays an important role in intimate relationships and friendships, the present study reveals a distinctive anti-reciprocity effect if this need is not satisfied in initial encounters with potential romantic partners."

Male sweat boosts women's hormone levels

Just a few whiffs of a chemical found in male sweat is enough to raise levels of the stress hormone cortisol in heterosexual women, according to a new study by University of California, Berkeley, scientists.

The study, reported this week in The Journal of Neuroscience, provides the first direct evidence that humans, like rats, moths and butterflies, secrete a scent that affects the physiology of the opposite sex.

"This is the first time anyone has demonstrated that a change in women's hormonal levels is induced by sniffing an identified compound of male sweat," as opposed to applying a chemical to the upper lip, said study leader Claire Wyart, a post-doctoral fellow at UC Berkeley.

The team's work was inspired by previous studies by Wyart's colleague Noam Sobel, associate professor of psychology at UC Berkeley and director of the Berkeley Olfactory Research Program. He found that the chemical androstadienone - a compound found in male sweat and an additive in perfumes and colognes - changed mood, sexual arousal, physiological arousal and brain activation in women.

Yet, contrary to perfume company advertisements, there is no hard evidence that humans respond to the smell of androstadienone or any other chemical in a subliminal or instinctual way similar to the way many mammals and even insects respond to pheromones, Wyart said. Though some humans exhibit a small patch inside their nose resembling the vomeronasal organ in rats that detects pheromones, it appears to be vestigial, with no nerve connection to the brain.

"Pheromones are chemical molecules expressed by a species aimed at other members of the species to induce stereotyped behavior or hormonal changes," Wyart explained. "Many people argue that human pheromones don't exist, because humans don't exhibit stereotyped behavior. Nonetheless, this male chemical signal, androstadienone, does cause hormonal as well as physiological and psychological changes in women. More cognitive studies need to be done to understand how androstadienone affects female cognitive functions."

One implication of the finding is that there may be better ways to raise cortisol levels in patients with diseases such as Addison's disease, which is characterized by low cortisol. Instead of giving the hormone in pill form, which has side effects such as ulcers and weight gain, "a potential therapeutic mechanism whereby merely smelling synthesized or purified human chemosignals may be used to modify endocrine balance," the authors wrote.

Sweat has been the main focus of research on human pheromones, and in fact, male underarm sweat has been shown to improve women's moods and affect their secretion of luteinizing hormone, which is normally involved in stimulating ovulation. Other studies have shown that when female sweat is applied to the upper lip of other women, these women respond by shifting their menstrual cycles toward synchrony with the cycle of the woman from whom the sweat was obtained.

Androstadienone, a derivative of testosterone that is found in high concentration in male sweat, and in all other body secretions, has garnered the most attention. However, though its effect on a woman's mood, physiological arousal and brain activity suggests that the chemical is a possible pheromone-like signal in humans, its effect on hormone levels was unknown.

Wyart and Sobel set out to test whether androstadienone affects hormone levels as well, focusing on the hormone cortisol. Cortisol is secreted by the body in times of stress, priming the body for "fight or flight."

In two trials, a total of 48 undergraduate women at UC Berkeley were asked to take 20 sniffs from a bottle containing androstadienone, which smells vaguely musky. Over a period of two hours, the volunteers provided five saliva samples from which cortisol levels were determined.

Compared to their response when sniffing a control odor (yeast), the women who sniffed androstadienone reported an improved mood and significantly higher sexual arousal, while their physiological response, including blood pressure, heart rate and breathing, also increased. This was consistent with previous studies.

In addition, however, the UC Berkeley researchers found that cortisol levels rose within about 15 minutes of sniffing androstadienone, and remained elevated for more than an hour.

Wyart noted that, though this is the first time a specific component of male sweat has been shown to affect women's hormones, other constituents of male sweat likely have a similar effect. The question remains: Which comes first - the change in cortisol level, which may induce a change in mood or arousal; or a mood change that increases cortisol levels?

"We next need to look at other hormones that could explain the diversity of effects of androstadienone on sexual arousal and mood," she said.

Looking for love on all the right Web sites?

Then look out for lies, says Cornell behavior researcher

If you're hoping for Cupid's online arrow, then watch out for tall stories and wide fabrications. Online daters, both men and women, usually fib about either their height or weight, and sometimes their age, according to a Cornell University communication researcher.

This study will be published in an upcoming Proceedings of Computer/Human Interaction (April 2007), an annual peer-reviewed journal, to be released this spring during a Computer/Human Interaction conference in San Jose, Calif.

Using a new method that measured the actual difference between profile information and reality, the study revealed that men systematically overestimated their height, while women more commonly underestimated their weight, said Jeffrey Hancock, an assistant professor of communication and the lead author on this study. "Surprisingly, age-related deception was minimal and did not differ by gender," he said.

About 52.6 percent of the men in the study lied about their height, as did 39 percent of the women. Slightly more women lied about their weight (64.1 percent) than did men (60.5 percent). When it came to age, 24.3 percent of the men were untruthful, compared with 13.1 percent of the women.

Hancock, Cornell doctoral student Catalina Toma, and Nicole Ellison, Michigan State University assistant professor, examined four popular dating Web sites, where users create their own profiles and initiate contact with others:, Yahoo Personals, American Singles and Webdate. Study participants -- users of these Web sites -- were recruited in New York City through advertisements in the Village Voice and The final sample included 80 participants, equally divided between genders.

After collecting information about the participants from their online profiles, the researchers measured each person's height and weight, and obtained their age from drivers' licenses.

What constituted a lie? For height, the discrepancy had to be greater than half an inch; for weight, the deviation had to be greater than five pounds; and for age, there had to be a difference of a year. The results: A higher percentage of participants lied about their weight than either their height or age. In fact, for almost two thirds of the participants, weight was incorrect by 5 pounds or more.

Hancock says that social research abounds on how men and women use different strategies for finding love. In general, men seek youth and physical attractiveness in a partner, while women look for the ability to provide as well as indicators of social status, such as level of education and career.

The pattern of lies -- frequent but slight -- suggest that deception in online dating profiles is strategic. "Participants balanced the tension between appearing as attractive as possible, while also being perceived as honest," Hancock said.

Since the study was completed, online dating sites have changed. They now inquire about general body types rather than request information on a person's specific weight, but the basic tension of trying to appear as attractive as possible without having a deception detected still applies, he said.