system
Given the following post, respond as if you're commenting on Reddit:
human
In the Avengers movie, how come near the end, Bruce Banner can suddenly control his rage and turn into Hulk? When at the beginning, he almost killed Black Widow? Was he being a dick?

In the Avengers movie, Hulk went berserk and almost killed Black Widow in a rampage due to him turning to Hulk (out of apparently uncontrollable anger)... then at the end he says "that's my secret; I'm always angry."
gpt
When he damaged the Helicarrier, he had just discovered that SHIELD had been lying to himself, Stark, and Rogers. He predictably lashed out at SHIELD personnel, starting with Agent Romanov, and continued to attack SHIELD personnel until Thor caught up to him. He also suffered a concussive blast and a twenty-foot fall just prior to transforming, though the extent of injuries Banner suffered before the event is unknown (they would have been healed). Direct contact with Loki's spear (a device with known mind-control properties) may have also provoked Banner.

When the invasion occurred in Manhattan, none of the three factors mentioned above came into play. From this we can deduce that Banner's control over the Hulk is generally pretty solid. He only loses control if *everything* goes wrong at once. It's also likely that sudden physical injury (not pain, but actual lesions, bone fractures, or physical trauma) can trigger an uncontrolled transformation, which is an unknown but critical factor. If Banner were to be injured in a car accident, he could kill tens of thousands in a metropolitan area.

Any insight into Banner's psychological state is pure speculation at this time, as Banner's current whereabouts are unknown to the World Security Council and SHIELD has "lost" all medical records pertaining to Banner that were created in the last 12 months. It has been speculated that Banner's control over his transformations is increasing, but the event on the Helicarrier proves that he is still extremely dangerous and no expense should be spared in containing him.