Maybe your child is an INTP
On the other hand, their ability to grasp complexity may also lead them to provide overly detailed explanations of simple ideas, and listeners may judge that the INTP makes things more difficult than they need to be. To the INTPs' mind, they are presenting all the relevant information or trying to crystallize the concept as clearly as possible.
I was definitely like this and I still am, although I'm finally getting better. I was always honest to a fault, especially as a child. In fact, I didn't even want to say things that were true but insincere, because I felt implicitly that it was too close to lying. So if I was eating a delicious meal, and everyone around the table was saying something nice, I would hesitate because I knew that I was expected to say something, but I may not have normally.
He probably is an INTP, although it's too early to tell. I am too. That doesn't really answer the question:)
I've seen an article on LW about Santa Claus and most people were very keen on not lying to their kids (and I agree). I have a little kid who is generally quite truthful, innocent enough not to lie in most cases. I noticed recently that when someone asks him, "How are you", he usually answers in detail because, well, you asked, didn't you? When I was a teenager I hated people who lied and I tended to ignore these unwritten social rules to the extent I could. I.e. I didn't ask if I didn't want to know and people thought I was rude. So, my question is, should I teach him to lie upon these occasions?
More broadly, I was thinking, why am I committed to being truthful, in general? I guess because I would hate to be lied to myself. This is a kind of magical thinking maybe, or maybe it's a part of the social contract. This sort of lying in fact promotes the social well-being because to answer truthfully creates an unwelcome burden on my interlocutor who asked out of politeness and is not in truth interested. But it still feels wrong to lie. Even more wrong to teach your kid to do so.