When the Introverted Thinker was about three, I noticed that her assent was not an assent.
When I would tell her to do or not to do something, she would make a noise. "Hmm-hmm." A higher note followed by a lower one. It sounds like "Mmm-hmm" unless you listen closely. This is not an assent, but an acknowledgement. I studied her when I realized that she was not agreeing with what I was telling her. "I hear you," I say, "And I hear that you are not saying Mmm-hmm. I still mean it, even if you don't agree."
Clever little rat, isn't she? Making a sound that sounds like agreement but is non-committal. My daughter makes me believe in epigenetics. I think the genes for questioning authority came from both my parents. And both her parents. And back through the family past the last man to be publicly hanged for poaching Sherwood Forest, to whom we are related, to other rebels and trouble makers. Even as a small baby, the IT would study me when I made any statement. "The sky is blue." Her eyes would look at me. I know she is thinking about what I say and deciding for herself: is this person trustworthy? Do they know what they are talking about? Do I agree with them? Is the sky blue?