When we think about our emotions, we tend to think of them solely as states of feeling. For example, we tend to describe happiness as the state of feeling joy or pleasure. According to the late psychologist Robert Plutchik, emotions are much more complex than most people realize.
Emotions have a long evolutionary history. Our emotions are not only adaptive, but they have evolved over time in order to increase our reproductive fitness. Emotion plays an important role in issues of survival. Emotion also involves both cognition and behavior. For example, let's say that you were approached by a snake (threatening event). You would conclude that you were in danger (cognition), which would cause you to feel fear (emotion). Your fear activates the fight-or-flight response. As a result, you slowly back away from the snake in an attempt to escape (goal-directed behavior).