Teenage Sexual Maturity

The Economist:

IT HAS long been a puzzle that girls who grow up without their fathers at home reach sexual maturity earlier than girls whose fathers live with them. For years, absent fathers have taken the blame for this, because growing up quickly has negative consequences for girls. For example, early-bloomers are more likely to suffer depression, hate their bodies, engage in risky sex and get pregnant in their teen years.
It could be a simple matter of not having as many eyes, particularly suspicious fatherly ones, watching over daughters. Or it could be a complicated physiological response to stress, in which girls adapt their reproductive strategy to their circumstances. If life is harsh, the theory goes, maybe they need to get their babies into the world as quickly as possible.