According to an article in The New York Times, an increasingly high number of young girls are hitting puberty before they turn 10. However, endocrinologists and scientists have not determined a clear cause for this early development in young girls. The childhood obesity epidemic (fat can trigger hormonal production) and certain chemicals in plastics and cosmetics are suspected to be the culprit but no one knows for certain. Normal puberty, which includes the beginning of menstrual cycles, takes place between ages 10-16 ½. But as The Times suggests, early puberty might just be the new normal.