Wow, when I was a youngster 12 was considered early. I wonder if it has anything to do with hormones in the food.
No. Even way back when a small percentage of girls started their menses at 9 or 10
“...I wonder if it has anything to do with hormones in the food.”
I believe you are correct. It must be those hormones.
Nine and ten happens now. Periods start when a certain proportion of physical size and fat is reached. With heavier kids these days, it trends earlier. 125 years ago, periods started at 16 +/- and then people married a couple years later. Now girls have years of horny hormones to contend with before marriage. Used to be that asking them to wait for marriage wasn’t such the big ask that it is now. Sorry for the tangent.
It may have something to do with “hormones in the food”, but it has mostly to do with the food itself. Very well nourished children tend to mature earlier than not as well nourished children.