"George Davey Smith, a clinical epidemiologist at Bristol University, said: “It suggests that earlier puberty does influence early age of sexual debut, which then appears to have other consequences such as, all things being equal, earlier first birth, having more children, less likely to remain childless, and poorer educational outcomes.” While early puberty has been linked to poor educational achievement before, he said, the latest study strengthened the evidence that early puberty was a cause, and not simply a reflection of underlying factors, such as social class."