People are reaching puberty earlier too, and growing taller. I don't think this is a coincidence. Baldness is a hormonal problem and certain hormones are becoming active at younger ages. As to folliclular receptor sensitivity, I doubt anything has changed with them.
It's not clear that Americans for example are still growing taller.
See this article:
http://abcnews.go.com/Technology/story?id=98438
