Emotion is the subjective, internal experience caused by a group of biological reactions arising in response to some situation (as opposed to the emotion being consciously willed to occur). There is a feeling, or affective, response (sadness, anger, joy), a physiological response (changes in internal bodily functioning), a cognitive response (an interpretation of the situation), and possibly also a behavioral response (an outward expression).

Questions concerning the mystery of human emotion were the territory of a 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 James-Lange theory proposes that conscious conclusions about what we are "feeling" form in reaction to physiological changes occurring in the body. This was proposed by William James and Carl Lange independently in the 1880s.
  • The Cannon-Bard Approach proposes that the lower brain initially receives emotion-producing information and then relays it simultaneously to the higher cortex for interpretation and to the nervous system to trigger physiological responses.
  • The Schacher-Singer Approach gives highest importance to the cognitive skills that create an interpretation of the situation and so provide a framework for the individual's behavioral response.
  • The Opponent-Process Approach views emotions as sets of pairs, one positive and one negative. When an emotion-producing stimulus is present, one of the pair is suppressed so that the more situationally appropriate emotion is felt intensely.

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).

Principally involved in the physiological component of emotion are: the autonomic nervous system (ANS), the limbic system, and the hypothalamus.

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.

A person's way of an ardent demonstrative heart-felt expression dictated by the intellectual judgement at and for a particular moment.

Emotion is a result of the mind reacting or responding on prompted situation. A person's greatest emotional source is the brain. It is the core of all activity in human function. The actions taken could be physical or psychological. Emotions are from the psychological results of varried experiences, past and present. Prompting a person to react in many different ways. Emotion is never conrolled. For even if you have controlled your supposed reaction, it remains an emotional stress. Usually, our reactions comes from peoples actions towards us. Even when we are alone, we will arrive at a certain reaction towards ourself like boredom or sadness making us emotional without noticing it. Without show of emotion.. a person is considered dead. Insensitive people are the least to show emotion but that it doesn't mean they are without it.

Philosophers have considered the problem of emotions from a number of different angles, and in recent years have attempted to integrate, or at least relate, accounts of emotion found in literature, psychoanalysis, behavioural psychology, neurobiology and in the philosophical literature itself. Martha Nussbaum, to take one example, has issued a recent challenge to theorists of emotion who understand emotions to be irrational states grafted onto a rational, emotionless thought process. This understanding of emotions may be considered the epiphenomenal account; emotions may be the end-product of cognitive processes -- such as a feeling of anger upon realizing that one's been cheated -- but they can never take their place among other mental states, such as believing, as equals. In this account, one may, for example, reason perfectly well about an ethical quandary without experiencing emotion.

In Nussbaum's account, emotions are essentially cognitive states of a subject; what distinguishes emotions from other thoughts is that they refer to events or states in the world that directly relate to what she terms the individual's own self-flourishing. Here, self-flourishing refers to a constellation of concepts taken from the Aristotelian notion of Eudaimonia.

Nussbaum's primary goal in her recent work on emotion is to support this cognitive account of emotions against the epiphenominal account by showing how emotions both have a logic -- can be considered to follow coherently or not upon one another -- and are directly responsive to external facts. For Nussbaum, the fact that the emotion of jealousy can coexist with that of love, but not with that of, say, friendly-feeling, is a consequence of their cognitive properties. Accounts of psychoanalysis and of the sequence of emotions experienced when listening to music are also, in Nussbaum's view, supportive of the cognitivist account.

See also Emotion theory, List of emotions, Empathy

Further reading