By Science News, 01:39 AM December 27, 2012

Early puberty’s cause
Regarding “Early Arrival” (SN: 12/1/12, p. 26): In 1960 I left the Ohio Valley of grass- and corn-fed cows to teach in the Los Angeles area. When I arrived, I found that eighth- and ninth-grade girls looked physically like 25-year-old women in Ohio. I asked the other teachers what was going on. They all responded, “beef growth hormones.” If researchers would track earlier puberty in preteen girls alongside the use of growth hormones in cattle, they would most likely f...

Source URL: https://www.sciencenews.org/article/letters-127