Girls Who Try Sex Early Driven by Genes

Absentee fathers may not be at fault for daughters who experiment with sex at an early age, the Economist reports. Researchers have long noted that girls with no dad around tend to reach sexual maturity earlier, suffer from depression, criticize their bodies, and get pregnant early on. But a new study suggests that runaway fathers and girls' sex experimentation may have the same cause: genes.

American researchers looked at 1,382 boys and girls, each related as cousins through their mother's side of the family. The cousins most closely related had sex around the same age, regardless of whether their father was around. The study's author isn't sure why, but says their mom's genes may have made her equally impulsive—and led her into an early marriage that was more likely to break up.
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