How Girls Are Developing Earlier In An Age Of 'New Puberty'

Many girls are beginning puberty at an early age, developing breasts sooner than girls of previous generations. But the physical changes don't mean the modern girls' emotional and intellectual development is keeping pace.

Two doctors have written a book called The New Puberty that looks at the percentage of girls who are going through early puberty, the environmental, biological and socioeconomic factors that influence when puberty begins, and whether early puberty is linked with an increased risk of breast cancer.

“ What I find concerning is that puberty is a process that's very sensitive to the environment and we can move the timing of puberty, unintentionally.
- Julianna Deardorff, co-author of The New Puberty
"It has been established that girls who enter puberty earlier are more likely to have symptoms of anxiety, higher levels of depression, initiate sex earlier and sexual behaviors earlier," Julianna Deardorff tells Fresh Air's Terry Gross.

Deardorff and Louise Greenspan are co-investigators in a long-term study of puberty. They've been following 444 girls from the San Francisco Bay area since 2005, when the girls were 6 to 8 years old. The study is funded by the National Cancer Institute and the National Institute of Environmental Health Sciences.

Deardorff says that while early puberty could be hard on a young girl, family and school support matters.

"The family can serve as a huge buffer against some of those negative effects of early puberty," she says. "There's also been some research to show that certain aspects of the neighborhood context and also schools can be protective. ... It can completely mitigate the risk associated with early puberty on girls' emotional and behavioral functioning."

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