Why girls are dealing with puberty earlier than ever before

Having your first sex ed class in the seventh grade used to make a lot of sense. You get to learn about puberty and sexuality at the same time, collect your mysterious gift bag, and then go home, where you can start having a sort of awkward but super important conversation with your parent or guardian.

But today, a lot of girls are starting puberty so early that Dr. Louise Greenspan and Dr. Julianna Deardorff suggest that we might want to start puberty education well before sex education. These two doctors have been tracking over 400 girls in the San Francisco area for the last nine years in one of the largest long-term studies of puberty ever. Together, they’ve written The New Puberty, a book that summarizes their findings and offers advice for parents and caretakers of young girls. What they discovered will surprise you and it should have a huge impact on the way we teach girls about their bodies.

In an interview with NPR, Drs. Greenspan and Deardorff recall that age eight used to be the earliest we would expect puberty to start for girls. But now―depending on what physical signs you use to measure it―anywhere from 10 to 15 percent of girls are going through the initial stages of puberty at age seven. By age eight, between 19 and 27 percent of girls are already starting to show signs of physical development. The doctors are careful to point out that this doesn’t necessarily mean that periods are starting earlier―although that’s slowly happening, too―but it does mean that girls’ bodies are changing earlier than ever.

It seems like the age of puberty is one of those things that shouldn’t be able to change, right? So how can it be dropping? So far, researchers have a lot of theories but not a lot of answers. In their book, Drs. Greenspan and Deardorff suggest that certain chemicals found in almost all of our plastics might be acting like estrogen, triggering early puberty. They’re also concerned about the effects of the antibiotics we give to animals. Chickens that get fed antibiotics go through puberty earlier so we can eat them sooner. If girls are absorbing those antibiotics, too, there’s a possibility it’s having a similar effect on them.

But if we still don’t know why this is happening or if we can stop it, then it’s time to make some serious adjustments to the way we teach girls about puberty. Drs. Greenspan and Deardorff especially want parents to be aware that girls who go through early puberty might be more likely to get involved in substance use and sexual behavior earlier than their peers because people perceive them as being older than they actually are. They also believe that starting puberty education earlier―for both girls and boys―will help girls prepare girls while also helping boys understand how to behave appropriately and respectfully.

Above all, the doctors believe that we all need to be ready to start the puberty conversation earlier in an honest, straightforward, and compassionate way. It’s hard growing up, especially when everything, even our own bodies, are changing so fast.