My response to watching:
I have yet to hear two people communicate in silence. Silence is a response but gets lost in translation if used bidirectionally. Not to say that "holding our tongues" doesn't have it's appropriate practice. We don't respect our language. It's grossly taken for granted.
My new perspective on language and its development is that it closely matches our own development to maturity. People who talk like babies or little at all (other than just "quiet spoken" people) are likely to be in that stage of development. People who speak like professional adults tend to be employed and mature people, even if they are mature beyond their years. I watched a documentary on a 19 year old entrepreneur who speaks beyond his chronological years. At 15 years old he was a college freshman.
When you have a high level of vocabulary, you are more likely to have more complex, abstract (related to adult stage of development) and creative thoughts. This level of thought, creativity and logic are unique to the individual but many times has a group influence. I think the best way to fuel language development is through conversation, writing (even with bad spelling) and reading. Any lacking in those activities will stifle a young person from (dare I say) maturing and becoming the person they were designed to become genetically.
I knew a child who did not talk a few years ago. I gave my talk/write/read theory for language (and even relationship) development a test drive. I talked to him when other people tried to intuit with him. I told him that everything he needed to learn, he's already heard for many years of his life (changing the task from learning to recognition). When I developed a relationship through talking (rapport), I then helped him learn to read. His emerging reading skills then reinforced his speaking vocabulary and his sleeping auditory index was awakened. When he gained confidence in reading, he dared to write. And now- he is writing his own short plays and sharing his subject view of the world.
Language, relationship, and maturation are all so closely intertwined, that weakness in one of those areas wreaks havoc on the other two. The same way I can assure him that a sentence that has the word "cat" will most likely also have a word like "meow", "fur", "tail", "purr" and "animal." I am now helping him sift through the predictable parts of his life so that he can focus his energy on the ones that are growing (like his academic life, relationships, conversation). I'm trying to get him to trust that an arrow pointing in a direction with the plane sign means that if we go that direction- that will take us to the airport. Or, if it it's the first meal of the day- that means it's breakfast. Or, Christmas is always in December.
Now that he is learning more about the world around him and the words that correspond with those qualities, I hope he'll start assigning words that describe him and his preferences. When his stock phrase was "I don't know," I'm holding out for the day he will say some adjectives about himself. I'm hoping some of those words will be: funny, smart, handsome, interesting, a builder, brother, son and future father. So- not that we can't intuit each others meanings, now we have the words to describe our thoughts and interactions.
With language, now he has an identity and a very bright future. I hope I can see one of his plays or screen plays on the big screen some day!