Plutchik's psychoevolutionary theory of basic emotions has ten postulates.
- The concept of emotion is applicable to all evolutionary levels and applies to all animals including humans.
- Emotions have an evolutionary history and have evolved various forms of expression in different species.
- Emotions served an adaptive role in helping organisms deal with key survival issues posed by the environment.
- Despite different forms of expression of emotions in different species, there are certain common elements, or prototype patterns, that can be identified.
- There is a small number of basic, primary, or prototype emotions.
- All other emotions are mixed or derivative states; that is, they occur as combinations, mixtures, or compounds of the primary emotions.
- Primary emotions are hypothetical constructs or idealized states whose properties and characteristics can only be inferred from various kinds of evidence.
- Primary emotions can be conceptualized in terms of pairs of polar opposites.
- All emotions vary in their degree of similarity to one another.
- Each emotion can exist in varying degrees of intensity or levels of arousal.