A year or so ago, I was driving home from my in-laws with just the middle daughter. (I work near them, so I will come directly from work while my wife will drive from home with the three kids and the dog.) Anyway, the middle daughter was a champion at stream-of-consciousness dialog. Just to test her, I resolved to give her nothing to work with: I would say nothing and see how long it took for her to stop talking--maybe she would ask a question or just run out of steam. Well, she made it the whole 20 minutes; nonstop chatter.
Today, I tried the same thing except this time she was silent. Lost in her own thoughts, not a word was uttered the whole way home. Once home, I opened up the door and she disappeared upstairs while I turned to cleaning the kitchen.