When you analyze parent child language in the first year of life, what you find is that most of it is playful. What children laugh at or don't laugh at is always underpinning the actual language acquisition. I've got a recording here of two three-year-old girls playing together and they're all having a great time. They're not laughing at each other, but they are enjoying the humor of language play. And this is always there. So if neither of us were standups, as it were, nonetheless, when we're having a conversation in the book, people are always playing with language,.