It’s a good thing little girls grow up, or Homo sapiens would have become extinct long ago. It’s probably a good thing little boys grow up too, for the same reason. When I listen to our grandchildren fight with each other, I wonder how we have survived as a species for so long. It gets even more amazing when I consider that when they repeat the things their mother’s twenty-something friends say, they don’t seem particularly incongruent on the lips of a three or five-year old.