4. He Avoids Eye Contact With People He Doesn't Care About
Something that's been apparent since Downey's very first screen test for Iron Man is that his Tony Stark avoids making frequent eye contact with people who he doesn't care about or perceive as on his level. Note that in the screen test, he intensely focuses his eyes on a beautiful woman while talking to her, but in the next scene, he's constantly averting his gaze while talking to two soldiers (remember, pre-capture, he didn't give a damn), and when talking to a stand-in for Rhodey, he again is laser-focused as the two are best pals. This is a trait that Downey has carried through all of the movies, a classic example occurring in The Avengers, as when Tony gives his famous "genius, billionaire, playboy, philanthropist" speech to Captain America, he looks away from Cap until the very last moment, as if to make his gaze that much more piercing when he finally, briefly, looks Cap in the eye, a man he hasn't yet grown to respect. And of course, after The Avengers, Tony looks Cap in the eye every time they speak.