A mood is an emotional state. Moods differ from emotions in that they are less specific, less intense, and less likely to be triggered by a particular stimulus or event. Moods generally have either a positive or negative valence. In other words, people typically speak of being in a good mood or a bad mood. Mood also differs from temperament or personality traits which are even longer lasting. Nevertheless, personality traits such as optimism and neuroticism predispose certain types of moods.