This is not to say that babbling is not an important part of learning to talk, only to question which came first—babbling so as to develop into a talker, or a predisposition to evolve into a talker because among cooperative breeders, babies that babble are better tended and more likely to survive."
If they are exposed to sign language, they will babble with their hands at approximately the same time vocal babbling appears, although sign production appears a few months before word production generally does in hearing children.
Most babbling consists of a small number of sounds, which suggests the child is preparing the basic sounds necessary to speak the language to which he is exposed.
