In Divergent (2014), we learn what a divergent is and that they are rare. When Tris joins Dauntless, she meets Four who seems to be very careful, calculating and in control.
During the fear test, he figures out that Tris is a divergent because she can beat the test unlike any he has seen before. "Dauntless don't break the glass like that." But he doesn't do anything about it.
We see later on that his back tattoo consists of all of the faction symbols because, "he doesn't want to just be one thing".
Later when Dauntless is taken over and all of the members are under mind control, it's revealed that Four is pretending, he is very much immune to the mind control as Tris is (or maybe he didn't get injected?).
Based on these facts, I assume Four is also a divergent. But, his own fear test makes me think otherwise. Is he capable of escaping the test as Tris is, but chooses to endure it for the show or what?
Is Four a divergent and if so, is it revealed anywhere in the movie, subtle or otherwise?