Maybe it is better diet, maybe exposure to light, nobody is really sure. It has dropped several years in the past 100.
Looking at these old photos, I am struck by how young the kids look. Probably this group is pre-selected for poor diet, they do not appear to be children of the affluent. But if the ages are correct, they would look a lot more grown up today. What do you guys think? I am thinking that my age of sail, age of Marlowe kids may have looked kid-like longer than I am calibrated for.
There is one very strange study out there that says that a girl who lives in the same house with her biological father will have later onset menarche than a girl who does not. That is one of those weird findings you just want to poke at until the facts make sense, so strange.