The most incisive guide to issues facing the American family today . . . An invaluable resource for anyone wishing to stay on the cutting edge of research on family trends.

-W. Bradford Wilcox
Associate Professor of Sociology, University of Virginia 

11-Year-Old Girls, Going on 18

Bryce J. Christensen and Robert W. Patterson

Public-health officials in the United States and Western Europe have expressed increased concern about the number of girls who experience puberty at a disturbingly early age. Analyzing this development, pediatric researchers at the University of Athens highlight adverse changes in family life as a prime reason that many girls’ bodies are undergoing physiological changes before they are emotionally and socially prepared to deal with such changes.

Though they acknowledge data suggesting that the trend may finally be slowing down or stabilizing, the Greek scholars limn “a continuous trend for earlier ages at menarche for the most part of the 20th century.” The analysts cite, in particular, data from the United States showing that, before 1900, the average American girl was older than 14 when she experienced menarche, compared to just 12.43 years in an American study conducted between 1988 and 1994, and 12.34 years in a Boston-based relying on data from the 1990s.

Clarifying why this trend disturbs medical authorities, the Greek scholars note that early menarche predicts a number of health problems, including “increased body mass index, insulin resistance, total number of metabolic syndrome components and hence increased cardiovascular risk.” But perhaps even more worrisome are the psychological, social, and behavioral problems associated with early puberty. The researchers point to studies concluding that early menarche predicts “anxiety symptoms, depression, premature intercourse and violent behavior.”

Because of their desire to reduce the incidence of such problems, the researchers seek to explain why girls in the United States and elsewhere have been entering puberty at such early ages. Although they stress that “the onset of menarche cannot be attributed to a single factor,” their analysis highlights the effects of family disintegration in fostering early puberty among girls. “Absence of a biological father, [and] the presence of half- and step-brothers is associated with early menarche,” the researchers report, “whereas the presence of sisters, especially older ones, in the household while growing up, [is] associated with delayed menarche.” Probing further, the researchers adduce evidence that “the prevalence of early menarche is even higher when stepfather presence is combined with a stressful family environment and with maternal mood disorders.”

Given the way that the divorce revolution has dramatically multiplied the number of stepfamilies in the United States, pediatricians have every reason to expect a growing number of girls entering puberty too soon. Americans distressed by the consequences of such early puberty therefore have every reason to search for ways to reverse this disastrous revolution.

(Olga Karapanou and Anastasios Papadimitriou, “Determinants of Menarche,” Reproductive Biology and Endocrinology 8 [September 30, 2010]: 115.)