Puberty starts earlier than it used to -- no one knows why
Arcia Herman-Giddens first realized something was changing in young girls in the late 1980s, while she was serving as director for the child abuse team at Duke University Medical Center in Durham, North Carolina. During evaluations of girls who had been abused, Herman-Giddens noticed that many of them had started developing breasts as young as 6 or 7.