Speech

I have really enjoyed learning about the speech development process. It has been even more interesting watching my 16 month old cousin go through this process. We discussed how a baby begins babbling, then speaking in one word, eventually expanding to two words and finally speaking in full sentences. My cousin was taught sign language and was able to begin signing words, such as hungry, more, full. and please. She was able to sign these words before she was able to speak them. She has also very recently begun signing two word phrases such as more please. She is  abel to sign this before she speaks at this level since she is barely in the one word speaking stage. Could she and other babies who are able to sign before they speak a question against those who believe stage development is all cognitive and not because of the need for the muscles to develop.