U.S. teens are not as reckless as some people might think when it comes to sex, and they are much more likely to use condoms than people over 40, according to a survey released on Monday that could help guide public health policy.

The study from sex researchers at Indiana University and paid for by Trojan condom maker Church & Dwight Co is the most comprehensive look at sex behaviors in the United States in the past 20 years.

Some findings heartened public health officials -- one in four acts of vaginal intercourse involve condom use. And among people who are single, that figure is one in three.

Condom use is higher among black and Hispanic Americans than among whites, and is lowest among people over 40, the nationally representative Internet survey of 5,865 Americans aged 14 to 94 found.

The results, presented in nine peer-reviewed studies in the Journal of Sexual Medicine, debunked stereotypes about teens being reckless when it comes to sex.

Only 14 percent of 14-year-old boys reported any kind of sexual interaction with a partner in the prior three months, but almost 40 percent of 17-year-old males did, Indiana University researcher Dr. Dennis Fortenberry told a media briefing, adding that the findings were similar in females.

He said many teens reach age 18 with no sexual experience, and for those who do have sex, condom use is routine.

In this study, somewhere between 70 and 80 percent of adolescents reported condom use at their most recent vaginal intercourse, Fortenberry said.

This indicates we've had a real public health success that we need to acknowledge.

41 SEX PRACTICES

The team found that in the past 20 years, most adults have moved far from the traditional notion of sex as vaginal intercourse. People in the survey reported engaging in 41 sexual practices including oral and anal sex.

While vaginal intercourse is still the most common sexual behavior by adults, many sexual events do not involve intercourse, Indiana University researcher Debra Herbenick, an expert in women's sexual health, told a telephone briefing.

Other findings:

* Some 85 percent of men say their sexual partner experienced orgasm during sex, but just 64 percent of women say they did.

* About 7 percent of women and 8 percent of men surveyed said they are gay, lesbian or bisexual, but the number of people who have had same-gender sex is higher, the team said.

* About a third of women say they experienced pain during their most recent sex encounter, compared with 5 percent of men. Herbenick said more research is needed to understand why.

* Men are more likely to experience orgasm when sex includes vaginal intercourse, while women are more likely to when they engage in a variety of sex acts and when oral sex or vaginal intercourse is included, the survey found.

Herbenick said understanding U.S. adults' sexual experiences affects public health, a point also made by former U.S. Surgeon General Dr. Joycelyn Elders.

In order for physicians, nurses, pharmacists, and other healthcare professionals to provide sexual health information to their patients, they must first have the understanding of what the sexual behaviors are in the community and how they are manifested, Elders wrote in a commentary.

Dr. Kevin Fenton of the U.S. Centers for Disease Control and Prevention said the papers will help as the White House rolls out the new U.S. AIDS policy.

We must seize this moment, Fenton wrote in a commentary.