What best describes a person's sustained internal emotion that influences their perspective on life?

A sustained internal emotion that influences a person's perspective on life is best described as mood. Mood refers to a prolonged emotional state that can color an individual’s experiences and affect their behavior over time. Unlike emotions, which are usually more short-lived and tied to specific triggers or events, moods are more diffuse and can last for hours, days, or even longer.

Moods can significantly shape a person's outlook on various situations, leading to interpretations and reactions that align with their emotional state. For instance, someone in a good mood might perceive challenges as manageable, while someone in a bad mood may see them as insurmountable.

While affect refers to the immediate expression of emotion, and temperament describes the inherent personality traits that influence how an individual experiences emotions over the long term, it is mood that best fits the description of a sustained emotional state affecting life perspective. Emotions, on the other hand, are typically intense and short-lived responses to specific stimuli, making them less representative of the sustained impact that mood conveys on a person's view of life.