What is an emotion? “More than 90 definitions have been offered over the past century, and there are almost as many theories of emotion—not to mention a complex array of overlapping words in our languages to describe them. (Prof. Robert) Plutchik offers an integrative theory based on evolutionary principles. Emotions are adaptive—in fact, they have a complexity born of a long evolutionary history–and although we conceive of emotions as feeling states, Plutchik says the feeling state is part of a process involving both cognition and behavior and containing several feedback loops.” American Scientist Here’s an interesting table with various psychological theorists’ differing ideas about what the basic emotions are.