Little Boys Are Growing Up Faster

Puberty in boys occurring sooner than in past years

/ Author:  / Reviewed by: Chris Galloway, M.D.

(RxWiki News) If it seems like kids are just growing up too soon these days, it may not be your imagination. It turns out boys are going through puberty earlier.

A recent study has found that boys are hitting puberty about six months to two years earlier than reported in the past. The boys appear to be hitting the later stages of puberty at about the same rate as past studies.

They simply appear to be starting sooner.

The researchers could not determine what might account for the shift to younger puberty.

"Attend all well-child appointments."

The study was led by Marcia E. Herman-Giddens, PA, MPH, DrPH, of the Department of Maternal and Child Health at the Gillings School of Global Public Health, University of North Carolina at Chapel Hill.

Dr. Herman-Giddens and colleagues collected data on 4,131 boys from 212 health care practitioners in 144 pediatric clinics across the U.S.

Half the boys were white, and the other half was split evenly between black boys and Latino boys.

They found that boys were moving into the next stage of genital development (larger testicles) at age 10.1 for white boys, 9.1 for black boys and 10 for Latino boys.

Past studies, ranging from the 1950s up through the 1980s found boys developing into this stage at ages 10 to 12, depending on their race and the year. In general, the studies done in the 1950s to 1970s placed boys at 11.5 or older when they reached this stage.

Boys are also developing pubic hair earlier: 11.5 years old for white boys, 10.3 years for black boys and 11.4 years for Latino boys.

This conclusion is similar to what other studies have found regarding girls' starting puberty sooner. The researchers reported that similar trends have been reported in Denmark, Sweden, Great Britain, Italy and China.

"Current environmental factors, including exposure to chemicals, changes in diet, less physical activity, and other modern lifestyle changes and exposures may be related to this apparent rapid decrease in the age of onset of secondary sexual characteristics and may not reflect healthy conditions," they wrote.

The study was published October 20 in the journal Pediatrics. The research was funded by Pfizer, the American Academy of Pediatrics, Genentech Center for Clinical Research and Education, Health Resources and Services Administration, Maternal and Child Health Bureau, the Georgia Health Foundation and the AAP Research in Pediatric Practice Fund.

Five of the authors receive some of their salary from Pfizer, and one author has been paid for services by NovoNordisk and Abbott Pharmaceuticals. No other authors declared disclosures.

Reviewed by: 
Review Date: 
October 22, 2012
Last Updated:
October 23, 2012