If you have a relational show that has lots of words and lots of conversation, children will watch it. But you must make the show have compelling conversation, a compelling story, and characters that children like. If you do these things, children will tolerate and enjoy longer scenes, true conversation, and more complex ideas. You've talked a lot about the importance of the match between the words and the emotional content, the nonverbal communication. Well, different people have a different capacity for the richness and the complexity of their nonverbal communication.
Some people just feel very constrained.
They're much more reserved. They're not very emotive. But as long as that's their consistent style, as long as their words have always matched the affect they present, there is internal consistency. So a child may have two parents who have very different styles of communication. For example, in a family where the reserved Norwegian marries the expressive Italian, you will find major differences between the communication styles of each parent.