The male-female orgasm gap. The sex lives of 14-year-olds. An intriguing breakdown of condom usage rates, by age and ethnicity, with teens emerging as more safe-sex-conscious than boomers.
That's just a tiny sampling of the data being unveiled. The researchers say is the largest, most comprehensive national survey of Americans' sexual behaviour since 1994.
Filling 130 pages of a special issue of the Journal of Sexual Medicine, the study offers detailed findings on how often Americans have sex, with whom, and how they respond. In all, 5,865 people, ranging in age from 14 to 94, participated in the survey.
The lead researchers, from Indiana University's Centre for Sexual Health Promotion, said the study fills a void that has grown since the last comparable endeavour, the National Health and Social Life Survey, was published 16 years ago.
Biggest changes since last survey
Major changes since then include the spread of sexually transmitted diseases, the types of sex education available to young people, the advent of same-sex marriage, and the emergence of the Internet as a tool for social interaction.
Dr Dennis Fortenberry, a paediatrics professor who was lead author of the study's section about teen sex, said the overall findings of such a huge survey should provide reassurance to Americans who are curious about how their sex lives compare with others.
"Unless, like al-Qaida, you feel there's something abnormal about the American people, what these data say is, 'This is normal - everything in there is normal."'
The researchers said they were struck by the variety of ways in which the subjects engaged in sex - 41 different combinations of sexual acts were tallied, encompassing vaginal and anal intercourse, oral sex, and partnered masturbation.
Difference in orgasm
Men are more likely to experience orgasm when vaginal intercourse is involved, while women are more likely to reach orgasm when they engage in variety of acts, including oral sex, said researcher Debra Herbenick, lead author of the section about women's sex lives.
She noted there was a gap in perceptions 85% of the men said their latest sexual partner had an orgasm, while only 64% of the women reported having an orgasm in their most recent sexual event.
One-third of women experienced genital pain during their most recent sex, compared to 5% of men, said Herbenick, citing this as an area warranting further study.
The study, which began taking shape in 2007, was funded by Church & Dwight Co., the manufacturer of Trojan condoms. Questions about condom usage figured prominently in the study, but the researchers insisted the integrity of their findings was not affected by the corporate tie.
High condom usage in teens
Among the findings was a high rate of condom usage among 14 to 17year-olds. Of the surveyed boys who had sexual intercourse, 79% reported using a condom on the most recent occasion, compared to 25% for all the men in the survey.
However, the sample for that particular question involved only 57 teens in the 14 to 17 age range. That's far smaller than the thousands involved in latest federal Youth Risk Behaviour Survey last year which calculated condom use among sexually active high school students at 61%.
Findings are encouraging
"There's been a major shift among young people in the role condoms have in their sexual lives," he said. "Condoms have become normative."
Rates of condom usage among black and Hispanic men were significantly higher than for whites. The researchers said this suggested that HIV/Aids awareness programmes were now making headway in those communities, which have relatively high rates of the disease.
The lowest condom usage rates were for men over 50 - and the researchers said this was worrisome, raising the risk for disease since an increasing number of older adults had multiple sexual partners.
Other notable findings
While about 7% of adult women and 8% of men identify as gay, lesbian or bisexual, the proportion of individuals who have had same-gender sex at some point in their lives is higher. For example, 15% of the men aged 50-59 said they had received oral sex from another man at some point.
Among adolescent boys, only about 2% of the 14 year olds but 40% of the 17 year olds, said they had engaged in sexual intercourse in the past year.
The survey was conducted from March through May of 2009, with the assistance of Knowledge Networks, among a nationally representative sample of adolescents and adults. Once people were selected to participate, they were interviewed online; participants without Internet access were provided it for free.
The researchers said the 1994 survey was compiled through in-person interviews, while the new method, collecting data over the Internet, may help make respondents more comfortable about discussing sexual behaviours.
Dr. Irwin Goldstein, editor-in-chief of the Journal of Sexual Medicine, noted that the new study came more than 60 years after Alfred Kinsey - also based at Indiana University - published his groundbreaking report, "Sexual Behaviour in the Human Male."
"Just like then, these papers contain material that is avant garde and often considered off-limits," Goldstein wrote in a forward to the study. "At a time when we can have nudity on HBO but cannot use the names of our genitals on the evening news, there remains a need to continue research on sexual health."
(Sapa, October 2010)