These basic emotions are described as "discrete" because they are believed to be distinguishable by an individual's facial expression and biological processes.
A popular example is Paul Ekman and his colleagues' cross-cultural study of 1992, in which they concluded that the six basic emotions are anger, disgust, fear, happiness, sadness, and surprise.
[2] Ekman explains that there are particular characteristics attached to each of these emotions, allowing them to be expressed in varying degrees in a non-verbal manner.
This apparent ease of recognition has led to the identification of a number of emotions that are said to be basic, and universal among all people.
[5] On "constructionist" accounts, the emotion a person feels in response to a stimulus or event is "constructed" from more elemental biological and psychological ingredients.
Two hypothesized ingredients are "core affect" (characterized by, e.g., hedonic valence and physiological arousal) and conceptual knowledge (such as the semantic meaning of the emotion labels themselves, e.g., the word "anger").
In 1897, Wilhelm Max Wundt, the father of modern psychology, proposed that emotions can be described by three dimensions: "pleasurable versus unpleasurable", "arousing or subduing", and "strain or relaxation".
Dimensional models of emotion suggest that a common and interconnected neurophysiological system is responsible for all affective states.
[12] This model suggests that emotions are distributed in a two-dimensional circular space, containing arousal and valence dimensions.
[13] Russell and Lisa Feldman Barrett describe their modified circumplex model as representative of core affect, or the most elementary feelings that are not necessarily directed toward anything.
The model assumes that there is always an underlying arousal dimension, and that valence determines the direction in which a particular emotion lies.
[17] Robert Plutchik offers a three-dimensional model that is a hybrid of both basic-complex categories and dimensional theories.
Plutchik's model, as Russell's, emanates from a circumplex representation, where emotional words were plotted based on similarity.
Because of these differences, many cross-cultural psychologists and anthropologists challenge the idea of universal classifications of emotions altogether.
[45] Meta-analytic reviews show systematic developmental changes in emotion dynamics throughout childhood and adolescence and substantial between-person differences.
[48] In 1980, Robert Plutchik diagrammed a wheel of eight emotions: joy, trust, fear, surprise, sadness, disgust, anger and anticipation, inspired by his Ten Postulates.
[49][50] Plutchik also theorized twenty-four "Primary", "Secondary", and "Tertiary" dyads (feelings composed of two emotions).
Anger is classified as a "positive" emotion because it involves "moving toward" a goal,[62] while surprise is negative because it is a violation of someone's territory.