How and why would people seek to cultivate anger? Explain with an example.

People seem to seek out emotions partly on the basis of what will be useful and helpful in their social interactions. This desire to be effective competes with the desire to feel good, of course. Many strategies of emotion regulation are simply aimed at the goal of getting out of a bad mood or into a good one.
Sometimes people even seek to cultivate anger. People in one study preferred to listen to angry music rather than other types of music when they expected a social interaction that would require confrontation and assertion. (In contrast, participants anticipating a cooperative or constructive social interaction chose other types of music.)Thus, people seemed to anticipate that anger might be a useful emotion in the upcoming interaction, so they chose stimuli to help them get and stay mad. What's more, it worked! The angrier participants performed better in the confrontational situation.