Americans, on average, use a condom one in four times when they have vaginal sex, according to a recent survey that also finds men think women are having orgasms more than they are.

This new sex survey shows that condom use has increased among some groups, but promoting condom use – which prevents the spread of sexual transmitted diseases like AIDS – should remain a health priority, according to Michael Reece, the director of the Center for Sexual Health Promotion at Indiana University, which conducted the survey.

The results also indicate that condoms are used twice as often with casual partners as they are within relationships, a trend that is consistent for men and women of all ages. Meanwhile, blacks and Hispanics have higher rates of condom use than other racial groups, and adults over 40 are less likely to use them than younger people, the survey found.

There was also plenty of variety in the sexual repertoires of the 5,865 people ages 14 to 94 who were questioned. Adult men and women rarely engage in just one sex act when they have sex, according to the researchers.

The survey also revealed an interesting discrepancy: 85 percent of men report their partner had an orgasm during their last sexual encounter, meanwhile, only 64 percent of women report having had an orgasm. The researchers say this difference is too large to be explained by some men having male partners.

The survey, the National Survey of Sexual Health and Behavior, is one of the most comprehensive studies conducted on these topics in almost two decades, according to the researchers. Its findings included: 

  • There is enormous variability in the sexual repertoires of U.S. adults, with more than 40 combinations of sexual activity described at adults' most recent sexual event.
  • Many older adults continue to have active pleasurable sex lives, reporting a range of different behaviors and partner types. 
  • Men are more likely to orgasm when sex includes vaginal intercourse; women are more likely to orgasm when they engage in a variety of sex acts and when oral sex or vaginal intercourse is included.
  • While about 7 percent of adult women and 8 percent of men identify as gay, lesbian or bisexual, the proportion of individuals in the U.S. who have had same-gender sexual interactions at some point in their lives is higher.
  • At any given point in time, most U.S. adolescents are not engaging in partnered sexual behavior. While 40 percent of 17 year-old males reported vaginal intercourse in the past year, only 27 percent reported the same in the past 90 days.
  • Adults using a condom for intercourse were just as likely to rate the sexual extent positively in terms of arousal, pleasure and orgasm than when having intercourse without one.