"Puberty Before Age 10: A New 'Normal'?"

Many girls seem to be entering puberty much earlier than girls did a few decades ago. Research suggests the cause may be small amounts of estrogen-mimicking chemicals in the food and water supply. For kids and parents struggling with this phenomenon, doctors seem to have few answers besides redefining "normal." Some unhappy families are turning to less conventional practitioners. A closer look at the research reveals that the causes may be more complex than originally thought.

Elizabeth Weil reports for the New York Times Magazine March 30, 2012.