In the early 1980s, you couldn't walk down the street, enter a caddy shack, or go to a party at Tom Cruise's parents' house without seeing teenagers having sex. It was a simpler time. People were happy, the cars were huge, and Kenny Loggins did all the music.

So the stereotype goes. Those days are gone. According to a new study from the CDC, 29 percent of females and 27 percent males between the ages of 15-to-24-year-olds reported having "no sexual contact with another person ever." When the survey was last conducted in 2002, 22 percent of both genders reported they were chaste.

In an interview with the Associated Press, CDC health scientist Anjani Chandra characterized the decline in sexual activity as "small but significant," but wouldn't speculate on the reasons behind it. While teen sex numbers have been declining since 1988, Chandra cautions it is "difficult to look for a trend earlier than 2002 because previous surveys did not gather as much detail about various types of sex." The Washington Post's David Brown adds that "parts of the survey are now so explicit that even though the interviewer and subject are face to face, some questions are asked and answered using a computer screen so that the answers are completely private.

At Jezebel, Anna North notes the report is "based on self-reported data, not on spying on teenagers," potentially skewing the results since "it's always a possibility that the kids are lying" or embarrassed. North speculates that increased public awareness of STDs starting in the 1980s "could easily have scared some kids off of sex," though as Reuters points out, the study details an "overall increase in reports of the sexually transmitted disease Chlamydia" across the population as a whole. As for abstinence-only sex education, its impact seems minimal considering the decline in teen sex started way back in the late '80s.

In other words, the kids may be all right, but nobody knows why they're not knocking boots like they used to.