Puberty starts earlier in many American boys


Former Executive Editor, Harvard Health

Two years ago, new research showed that American girls were hitting puberty at younger ages than ever. The same thing is happening with boys: they are starting puberty almost two years earlier than they did 30 to 40 years ago. Why this is happening isn’t clear, but it could affect social and sexual behaviors.

More than 200 clinicians assessed the sexual development of 4,134 boys between the ages of 6 years and 16 years living in 41 states. Half the boys were white, one-quarter were African-American, and one-quarter were Hispanic. The average age of puberty was 10 years for white boys, which is about one-and-a-half years earlier than what has long been considered “normal.” The average age was 9 years for African-American boys, about two years earlier than expected; and 10 years for Hispanic boys, which is unchanged from before. The results were published online in the journal Pediatrics.

Why might this be happening? This study couldn’t say, though the researchers offered a few possibilities: excess weight, changes in diet, less physical activity, or the presence of chemicals known as endocrine disruptors in food and the environment. It’s also possible that the way the study was done may have contributed to the shift.

What does it mean?

In girls, early puberty has been linked with increased risk for developing breast cancer and increased likelihood of engaging in risky sexual and other behaviors. Right now, we don’t know if earlier puberty will affect a boy’s long-term health and development. Further work is needed to determine that.

Puberty is a confusing time. It may be even more so for younger children, who may not be emotionally or developmentally ready for puberty.

The findings are one more reason to keep the lines of parent-child communication open. “Do not wait for your children to come to you with questions about their changing bodies,” advises Dr. Henry H. Bernstein, professor of pediatrics at Hofstra North Shore-LIJ School of Medicine and a medical advisor to Harvard Health Publishing. “That day may never come! Instead, sit them down and talk openly and honestly. Reassure them that the changes happening to them are normal.”

Although early puberty is increasingly common, it can be a signal of a tumor in the brain, pituitary glands, or elsewhere; an underactive thyroid gland; or other medical problems. If there’s a young boy in your household, keep an eye on his physical development. If you see that he is beginning to grow pubic hair earlier than you think is “normal,” talk to his pediatrician—and talk to him about the changes he is going through.

Related Information: Eat, Play, and Be Healthy


  1. susjuly

    Some causes puberty usually begins with the consumption of foods that are not controlled. And there are some of the teenagers who accidentally eat similar foods that contain synthetic chemicals, where the food is not good for health. Of course it could result in the faster spur growth hormones in the body.

  2. Virginia Sparrow

    American children loved to eat meat and other foods that they don’t mind if that food is nutritious or not. So that the early puberty is developed. Well thank’s for this, we learned about everything related to this.

  3. Hair Growth Society

    No doubt the imbalanced diet cause early hairs.

  4. Mannylyn

    Foods are one of the causes to early puberty.

  5. Mimi

    The major factor why puberty starts at early age for American boys is the foods we eat.For some reason, we ingest synthetic chemicals and flavorings which are not good for health and would contribute to faster growth of hormones inside the body.

  6. david

    I’m now 67 years old, and have some degree of hair loss, and while it may not be a totally desirable situation for some men, I’ve found it to be a somewhat convenient and time-saving situation. I actually started wearing my hair very short even when it was in full bloom, and a growing number of athletes, actors, and others in all walks of life are shortening or shaving their locks as their personal preference. It is nothing to be ashamed of, and extremely commonplace and acceptable in today’s society. Certainly better looking than an obvious “comb-over” which many men try to adopt with very little success.

  7. HealthPundit

    One of the resons for early puberty might be intake of increased amount of hormones through food products such as beef.

Commenting has been closed for this post.