A persons amygdala is damaged, and he tends to get angry less than he used to. This suggests that the amygdala?

is involved in regulating emotions

Explanation:

The amygdala is part of the limbic system. The amygdala is thought to play an important role in decision making, memory and emotional processing. These emotions include fear, anxiety and aggression which can be linked with anger.

In fact, animal studies have shown that animals with a damaged amygdala are less aggressive.