By CARLA K. JOHNSON and MIKE STOBBE
AP Medical Writers
ATLANTA (AP) - Fewer teens and young adults are having sex, a government survey shows, and theories abound for why they're doing it less.
Experts say this generation may be more cautious than their predecessors, more aware of sexually spread diseases. Or perhaps emphasis on abstinence in the past decade has had some influence.
Or maybe they're just too busy.
"It's not even on my radar," said 17-year-old Abbey King of Hinsdale, Ill., a competitive swimmer who starts her day at 5 a.m. and falls into bed at 10:30 p.m. after swimming, school, weight lifting, running, more swimming, homework and a volunteer gig working with service dogs for the disabled.
The study, released Thursday, is based on interviews of about 5,300 young people, ages 15 to 24. It shows the proportion in that age group who said they'd never had oral, vaginal or anal sex rose in the past decade from 22 percent to about 28 percent.
The findings are sure to surprise some parents who see skin and lust in the media and worry that sex is rampant.
"Many parents and adults look at teens and sex and see nothing but a blur of bare midriffs. They think things are terrible and getting worse," said Bill Albert, chief program officer for the National Campaign to Prevent Teen and Unplanned Pregnancy.
There are other surveys of sexual behavior, but this is considered the largest and most reliable. "It's the gold standard," Albert said.
Health scientist Anjani Chandra of the Centers for Disease Control and Prevention described the decline in sex as small but significant. She declined to speculate on the reasons. It's difficult to look for a trend earlier than 2002 because previous surveys did not gather as much detail about various types of sex, she added.
However, data over the years on vaginal intercourse among never-married adolescents shows a steady decline since 1988. That seems to be in sync with other CDC studies showing an overall drop in teen pregnancy.
That the trend began in the late 1980s seems to undermine the idea that abstinence-only sex education - heavily emphasized during the 2001-2009 presidency of George W. Bush - is the explanation, Albert said.
But it is possible those messages contributed, he added.
Comprehensive sex education - which includes abstinence but also teaches contraception and safer sex skills - didn't go away during the Bush years, said Elizabeth Schroeder, executive director of Answer, a national sex education organization at Rutgers University.
"We have been redoubling efforts and it has made an impact on these statistics," Schroeder said.
Sam Dercon, a 17-year-old high school junior from Princeton, N.J., said he's learned to worry about the consequences of having sex.
"I do think that sexual education is taking away that idea that you are invincible," said Dercon, who is also a contributing writer to www.sexetc.org, a project of Rutgers-based Answer.
"There's always that fear of something going wrong with consequences that could screw up your future," he said.
The leading influence on sexual activity among young adults is what parents teach and what peers are doing, experts said. And for whatever reason, smaller proportions are "doing it" than in the past.
King, the busy Illinois teen, said she broke up with a boyfriend because "we didn't have time to hang out as much as we wanted to. We were both swimmers and the majority of the time we saw each other was at practice."
She is on the junior board for Robert Crown Center for Health Education, a nonprofit organization that teaches sex ed to students in the Chicago area.
She sees sex, alcohol, smoking and drugs as distractions to her goal of getting a college scholarship in swimming, she said.
"This generation is very focused on their future and not necessarily getting laid," agreed Washington, D.C.-based sex educator Yvonne Fulbright.
But she also suggested that some young men aren't making time for relationships.
"Some guys, at the end of the day, they'd rather channel their energy into music, playing their guitar or playing computer games," Fulbright said. "That's immediate gratification. People forget it takes work to woo somebody and keep her happy."
The study showed that 27 percent of young men and 29 percent of young women reported no sexual contact.
It looked at older adults, too. It was based on in-person interviews of about 13,500 men and women ages 15 to 44, conducted in the years 2006 through 2008. The results were compared with those of a similar survey done in 2002.
Participants were offered $40 for sitting for the interview, which usually lasted an hour and included answering very specific questions on a computer about oral sex, anal sex and other sexual activities.
Among other findings:
-More than half of young people who had oral sex said they did that before vaginal intercourse; that pattern was much more common in whites than blacks or Hispanics.
-Among young adults, the proportion who had had vaginal or oral sex declined. But the proportion who had anal sex held steady, at about 21 percent.
-For all ages in the study, women were more than twice as likely to have had sex with a same-gender partner than men were. That was true despite the fact that about the same proportion of male and female survey respondents described themselves as homosexual.
The explanation for that finding seems to be that women are much more willing to describe themselves as bisexual, or to at least acknowledge they find others of their gender attractive.
That may have a lot to do with television shows and other pop culture, which at times seems to celebrate woman-on-woman sexual contact, but not the same kind of behavior among men, said Michael Reece, director of Indiana University's Center for Sexual Health Promotion.
"My guess is women are just more likely to feel that's OK," he added.
There is an assumption that sex between females is more common among more educated women, perhaps experimenting with their sexuality during their college years. But the CDC study found that such behavior was more common among less educated women, Chandra said.
Mike Stobbe reported from Atlanta and Carla K. Johnson reported from Chicago.
Online: CDC report: http://www.cdc.gov/nchs