A simple definition1 of an emotion is a state that involves a 1) physiological response, 2) subjective experience, and 3) behavioral response.
Now let’s get to some examples:
1) Physiological Response: The first part is the body’s physical reaction. For example, when a person experiences fear his heartbeat will increase, his mouth will dry-up, and his palms will sweat.
2) Subjective Experience: The subjective experience of an emotion is just that – one’s personal experience. For example, some people may feel fear mildly, and others can be frozen by it. People’s experience of fear will have similarities but will not be the same.
3) Behavioral Response: Then there’s the behavioral response or expression of the emotion. For example, freezing, stuttering, running, and hesitating are just some expressions of fear. Sometimes there is no expression. Cultural and personal experience can condition one to suppress these external cues to the internal process.
1 Hockenbury, D. H. & Hockenbury, S. E. (2007). Discovering psychology. New York: Worth Publishers.
emotion by Victor Lavrent’ev