In the majority of the stories he’s appeared in over the last five decades, The Hulk has been a creature driven primarily by rage, and that’s been the case in the Marvel Cinematic Universe. Granted, following The Incredible Hulk, Bruce Banner’s been able to get better control over his monstrous side (minus a few mind control incidents), but the Green Goliath has been more animalistic than civil. However, when Hulk returns in Thor: Ragnarok, fans might see a more intelligent version of him while out in space.
Noting how Bruce Banner has secluded himself from the rest of humanity again following Avengers: Age of Ultron, Mark Ruffalo revealed to Ain’t It Cool News that we may see the Banner and Hulk personalities start to merge. Ruffalo elaborated:
It's very subtle, but the Banner/Hulk consciousness is beginning to meld a little bit. Who decided to leave? Was it Banner or Hulk? It's not really in the (cinematic) mythology of Hulk up until that moment to be that conscious and pro-active. It's interesting, right?
The relationship between Bruce Banner and The Hulk is a modern day Jekyll and Hyde story, but by having the two personalities come together, that gives the audience a whole new dynamic to chew on. There have been intelligent versions of the Hulk seen in the comics, ranging from his post-apocalyptic future counterpart, The Maestro, to his alternate personality Doc Green. Aside from being able to distinguish between the good and bad guys, Hulk is ruled by instinct, so if some of Banner’s composure can seep into Hulk’s mind, he’ll finally be capable of reasoning. That’s not to say that Hulk will necessarily be the genius Banner is in the MCU, but it does mean he’ll have more control over his actions. Just picture him consciously applying his massive power against foes and working out problems in front of him as opposed to what he usually does: destroy everything in his path.
During the final battle against Ultron and his army in Avengers: Age of Ultron, Hulk jumped aboard an aircraft to toss out the robot antagonist. Rather than return to his teammates, he opted to stay on the ship so he wouldn’t endanger Black Widow or anyone else around him. While not clearly stated, it did look like Hulk was acting different than he usually does, evidenced by how calm he was staring at the sky. Nick Fury later told Black Widow that the Quinjet crashed near Fiji, leaving Banner’s current whereabouts unknown. It’s still unclear how he’ll get involved in Thor: Ragnarok, but that added intelligence will certainly come in handy when he fights whoever the movie’s main antagonist is alongside the God of Thunder.
Moviegoers will see Hulk back in action when Thor: Ragnarok is released on November 3, 2017.