This is kid Tony, y'know? Who gets to spend time with his parents and Obadiah only if he makes himself quiet and unobtrusive. Who is still very much in the shadow of Howard, so yeah, he's learned that skill. Just as he learns the skill of being at the center of attention, jus as he learns how to push people away from him.

Which is not to say that's the only way to think of kid Tony Stark. I can totally imagine him being the biggest six year old showboat ever. This probably just means that I THINK ABOUT TONY STARK A LITTLE TOO MUCH, I SUSPECT.