I don't know if that is scientifically proven, but my two girls actually talked first before learning to walk, while my only son was the other way around. My daughters could clearly speak words and sentences before they turned two, whereas my son at that age was still struggling to pronounce certain words and phrases.Interesting, because the other thing I have heard is that a boy will walk first while a girl will talk first. It applied to both the boy and the girl in the house.