Early sexual activity is risky for adolescents. Without proper sex education the health risks are large, and even with sex education there may be negative social and emotional consequences. But, despite what you might have read in today's headlines, sex at age 12 is not the norm for poor children.
Science Daily headlined the story, "Low-income Kids Report First Sexual Intercourse At 12 Years Of Age In New National Study," while the Chicago Sun Times led with "Poor Chicago kids have sex at young age." At the extreme, Radio Iowa culled the most extreme outliers to title their news story, "ISU study finds low income kids having sex as early as 8 or 9."
The actual study, published online by the journal Children and Youth Services Review was much more reasonably titled, "A Bioecological Analysis of Risk and Protective Factors Associated with Early Sexual Intercourse of Young Adolescents."
The study surveyed adolescents in low-income families in Chicago, Boston, and San Antonio. What they actually found was that 32% of boys, and 17% of girls, had sexual intercourse by the age of 16. Put another way: 68% of low-income boys and 83% of low-income girls, remained celibate until age 16! The "First Sexual Intercourse At 12" screamer is only based on the average age of those who reported first intercourse. And actually it was 12.8, so it should be rounded to 13, not 12. A science editor should know that.
[Update: I now see that the "12 years old" line came from the researcher herself, Brenda Lohman, as reported in the Iowa State University news release. Science Daily reprinted much of the news release almost verbatim. If you are 12.8 years old we still call you "12," but when a group has the average age of 12.8 we should round it to "13" instead of "12".]
The results confirmed that boys, especially African American boys, had higher rates of sexual activity. But some details that don't seem to have made the headlines are also important. Most notably, when other factors were controlled, children of single mothers had the lowest rates of sexual activity, compared with those of married or stably-separated parents, or those who entered into new relationships.
Why would poor children of married parents be more likely to have early sex? Maybe they have bigger houses, with their own rooms. Maybe they have cars. Or other privileges that make them attractive in the teen sex market. That's something we could do a study on -- but don't look for a splashy headline when it's done.