Friday, January 30, 2009

Observers of First Dates Can Predict Outcome

When it comes to assessing the romantic playing field -- who might be interested in whom -- men and women were shown to be equally good at gauging men's interest during an Indiana University study involving speed dating -- and equally bad at judging women's interest.

Researchers expected women to have a leg up in judging romantic interest, because theoretically they have more to lose from a bad relationship, but no such edge was found.

"The hardest-to-read women were being misperceived at a much higher rate than the hardest-to-read men. Those women were being flirtatious, but it turned out they weren't interested at all," said lead author Skyler Place, a doctoral student in IU's Department of Psychological and Brain Sciences working with cognitive science Professor Peter Todd. "Nobody could really read what these deceptive females were doing, including other women."

Place's study, published in the January issue of the journal Psychological Science, focused on the ability of observers to judge romantic interest between others because this ability has evolutionary benefits when it comes to finding a mate. Decisions that other people around us make, said Place, can influence or inform our own choices.

"So, if you walk into a room and there's 20 people you've never met before, being able to know which individuals might be available and which are clearly smitten by others can make you more efficient in finding your own romantic interest to pursue," he said.

For the study, 28 women and 26 men of college age watched video clips of couples interacting on speed dates. Speed dating is a popular commercial method for singles to meet a large number of individuals in one evening of successive brief one-on-one conversations. Each participant observed 24 videos, all with different men and women, and after each rated whether the man seemed interested in the woman and the woman in the man.

The speed dating sessions were all conducted in Germany while the observer ratings were all made by students in Indiana. Despite the language difference, observers were still able to judge men's romantic interest accurately using body language, tone of voice, eye contact, how often each dater spoke and other non-verbal cues.

"How people talk might convey more than what they say," Place said.

Observers did not have to see much of this non-verbal behavior. They were just as good at predicting the speed-dating couple's interest if they saw only 10 seconds of the date as they were if they saw 30 seconds. The researchers say this showed that observers, even with limited information, could make quick, accurate inferences using "thin slices" of behavior.

There was, however, great variability in how well observers could predict the interest of any particular speed-dater, ranging from 90 percent accuracy down to 10 percent. In five of the videos, 80 percent of the observers thought the women shown were interested when in fact they were not -- they were acting friendly even though they had no interest in the men.

Evolutionary theory, said Place, predicts a certain level of coyness or even deceptiveness in women because if a relationship is abandoned they may face greater costs, including pregnancy and child rearing. When choosing a mate, it is in a woman's best interest to get men to open up and talk honestly to give her a better idea of whether they would be good long-term partners.

"In a speed dating environment, you would expect to see these effects dramatically, with the women trying to get the men to be more straightforward, while they themselves remain more coy," Place said. "Though the pace is faster than a typical first date, the strategy remains the same."

Readers can see how successful they are at judging romantic interest by participating in a new online study that contains the same task as the one described here. To learn more or to participate in the 20-minute experiment being conducted by Place and his research colleagues, visit this site: https://www.indiana.edu/~abcwest/webexp/.

Monday, January 26, 2009

Pros. Cancer: Early Sex&Masturb =Bad, Later =Good

Frequent sex and masturbation in 20s and 30s linked to higher prostate cancer risk

But study also shows that risks diminish with age, particularly in a man's 50s

Men who are very sexually active in their twenties and thirties are more likely to develop prostate cancer, especially if they masturbate frequently, according to a study of more than 800 men published in the January issue of BJU International.

However the UK research team also found that frequent sexual activity in a man's forties appears to have little effect and even small levels of activity in a man's fifties could offer protection from the disease. Most of the differences were attributed to masturbation rather than sexual intercourse.

The study, led by the University of Nottingham, looked at the sexual practices of more than 431 men who had been diagnosed with prostate cancer before the age of 60, together with 409 controls.

Men who took part in the study were asked about all aspects of their sex life from their twenties onwards, including how old they were when they became sexually active, how often they masturbated and had intercourse, how many sexual partners they had had and whether they had had any sexually transmitted diseases.

"We were keen to look at the links between sexual activity and younger men as a lot of prostate cancer studies focus on older men as the disease is more prevalent in men over 50" says lead author Dr Polyxeni Dimitropoulou, who is now at the University of Cambridge.

"Hormones appear to play a key role in prostate cancer and it is very common to treat men with therapy to reduce the hormones thought to stimulate the cancer cells. A man's sex drive is also regulated by his hormone levels, so this study examined the theory that having a high sex drive affects the risk of prostate cancer."

The study participants, who were recruited by their family doctors, were asked to fill in a questionnaire about their sexual habits in each decade of their life since their twenties.

All the men with prostate cancer had been diagnosed in their fifties. Most of the men who took part in the study (97%) were white and the majority were currently married (84%) or widowed, separated or divorced (12%).

A number of interesting points came out of the study:

59% of the men in both groups said that they had engaged in sexual activity (intercourse or masturbation) 12 times a month or more in their twenties. This fell steadily as they got older, to 48% in their thirties, 28% in their forties and 13% in their fifties.
39% of the cancer group had had six female partners or more, compared with 31% of the control group.
Men with prostate cancer were more likely to have had a sexually transmitted disease than those without prostate cancer.
More men with prostate cancer fell into the highest frequency groups in each decade when it came to sexual activity (intercourse and masturbation) than men in the control group. 40% of men in the cancer group fell into the highest frequency category in their twenties (20 or more times a month) compared to 32% in the control group. Similar patterns were observed in the men's thirties and forties. By the fifties it had evened out, with 31% in each group falling into the most frequent category (ten or more times a month).
Men with prostate cancer were also more likely to masturbate frequently than men in the control group, with the greatest difference in the twenties (34% versus 24%) and thirties (41% versus 31%). The differences were less pronounced in their forties (34% versus 28%) and by the fifties the cancer group was slightly lower (25% versus 26%).
"What makes our study stand out from previous research is that we focused on a younger age group than normal and included both intercourse and masturbation at various stages in the participants' lives" says Dr Dimitropoulou.

"Overall we found a significant association between prostate cancer and sexual activity in a man's twenties and between masturbation and prostate cancer in the twenties and thirties. However there was no significant association between sexual activity and prostate cancer in a man's forties.

"A possible explanation for the protective effect that men in their fifties appear to receive from overall sexual activity, and particularly masturbation, is that the release of accumulated toxins during sexual activity reduces the risk of developing cancer in the prostate area. This theory has, however, not been firmly established and further research is necessary."