Questions concerning the mystery of human emotion were the territory of any number of disciplines until the development of modern psychology. Over the last century, psychologically-based theories have provided influential, if incomplete explanations of how emotional experience is produced.
The feeling component of emotion encompasses a vast spectrum of possible responses. Psychologists have attempted to offer general classifications of these responses, and as with the color spectrum, systematically distinguishing between them largely depends on the level of precision desired. One of the most influential classification approaches is Robert Plutchik's eight primary emotions - anger, fear, sadness, disgust, surprise, curiosity, acceptance and joy. Plutchik argues for the primacy of these emotions by showing each to be the trigger of behavior with high survival value (i.e. fear: fight or flight).
There is considerable debate as to whether emotions and emotional experiences are universal or culturally determined. One of the first modern attempts to classify emotions was Adam Smith's study, The Theory of Moral Sentiments. This book is based largely on data from Western Europe. Some anthropologists have explored the relationship between emotional disposition or expression and culture, most notably Ruth Benedict in her ethnological study, Patterns of Culture; Jean Briggs in her ethnography Never in Anger, Michelle Rosaldo in her ethnography Knowledge and Passion; Lila Abu-Lughod in her ethnography Veiled Sentiments; and Katherin Lutz in her ethnography Unnatural Emotions.
In his book Descartes' Error, the neurologist Antonio Damasio has developed a universal model for human emotions. This model is based on a rejection of the Cartesian body-mind dualism that he believes has crippled scientific attempts to understand human behavior, and draws on psychological case-histories and his own neuropsychological experiments. He began with the assumption that human knowledge consists of dispositional representations stored in the brain. He thus defines thought as the process by which these representations are manipulated and ordered.
One of these representations, however, is of the body as a whole, based on information from the endocrine and peripheral nervous systems. Damasio thus defines "emotion" as: the combination of a mental evaluative process, simple or complex, with dispositional responses to that process, mostly toward the body proper, resulting in an emotional body state, but also toward the brain itself (neurotransmitter nuclei in the brain stem), resulting from additional mental changes.
Damasio distinguishes emotions from feelings, which he takes to be a more inclusive category. He argues that the brain is continually monitoring changes in the body, and that one "feels" an emotion when one experiences "such changes in juxtaposition to the mental images that initiated the cycle".
Damasio thus further distinguishes between "primary emotions", which he takes to be innate, and "secondary emotions," in which feelings allow people to form "systematic connections between categories of objects and situations, on the one hand, and primary emotions, on the other."
Damasio has suggested that the neurological mechanisms of emotion and feeling evolved in humans because they create strong biases to situationally appropriate behaviors that do not require conscious thought. He argued that the time-consuming process of rational thought often decreases one's chances of survival in situations that require instant decisions.
Daniel Goleman and other investigators have researched what is entailed in the abilities to manage one's own and other people's emotions. See Emotional intelligence.
A person's mood is the emotion a human feels at a particular time.
See also Emotion theory.
There is still a need for more input from psychologists and philosophers here