Task: Identify the primary emotion conveyed in the tweet and assign it to either 'neutral or no emotion' or one or more of the provided emotions (anger, anticipation, disgust, fear, joy, love, optimism, pessimism, sadness, surprise, trust) that best capture the tweeter's mental state.
Tweet: In inter-group relationships, #anger makes people think in more negative and prejudiced terms about outsiders.
This tweet contains emotions: 
anger, disgust, optimism, pessimism, sadness