Emotion, in its most general definition, is an intense mental state that arises autonomically in the nervous system rather than through conscious effort, and evokes either a positive or negative psychological response. An emotion is often differentiated from a feeling.


Definition of emotion

Although a widespread word, it is not easy to come up with a generally acceptable definition of emotion. Growing consensus does agree that the distinction between emotion and feeling is important. According to Damasio, feeling can be viewed as the subjective experience of an emotion that arises physiologically in the brain.

Many psychologists adopt the ABC model, which defines emotions in terms of three fundamental attributes: A. physiological arousal, B. behavioral expression (e.g. facial expressions), and C. conscious experience, the subjective feeling of an emotion. All three attributes are necessary for a full fledged emotional event, though the intensity of each may vary greatly.

Robert Masters makes the following distinctions between affect, feeling and emotion: "As I define them, affect is an innately structured, non-cognitive evaluative sensation that may or may not register in consciousness; feeling is affect made conscious, possessing an evaluative capacity that is not only physiologically based, but that is often also psychologically (and sometimes relationally) oriented; and emotion is psychosocially constructed, dramatized feeling."[1]

Emotion is sometimes regarded as the antithesis of reason. This distinction stems from Western philosophy and is reflected in common phrases like appeal to emotion or your emotions have taken over. Emotions can be undesired to the individual feeling them; he or she may wish to control but often cannot. Thus one of the most distinctive, and perhaps challenging, facts about human beings is this potential for entanglement, or even opposition, between will, emotion, and reason.

In Paul MacLean's classic Triune brain model, emotions are defined as the responses of the Mammalian cortex. Emotion competes with even more instinctive responses from the Reptilian cortex and the more logical, reasoning neocortex. However, current research on the neural circuitry of emotion suggests that emotion is an essential part of human decision-making and planning, and that the famous distinction made by Descartes between reason and emotion is not as clear as it seems [2].

Emotion is complex, and the term has no single universally accepted definition[3]. Emotions create a response in the mind that arises spontaneously, rather than through conscious effort. It is unclear whether animals or all human beings experience emotion. Emotions are physical expressions, often involuntary, related to feelings, perceptions or beliefs about elements, objects or relations between them, in reality or in the imagination. The study of emotions is part of psychology, neuroscience, and, more recently, artificial intelligence. According to Sloman [4], emotions are cognitive processes. Some authors emphasize the difference between human emotions and the affective behavior of animals.

Emotion as the subject of scientific research has multiple dimensions: behavioral, physiological, subjective, and cognitive. Sloman argues that many emotions are side-effects of the operations of complex mechanisms (e.g. 'alarm' mechanisms) required in animals or machines with multiple motives and limited capacities and resources for coping with a changing and unpredictable world, just as 'thrashing' can sometimes occur as a side-effect of scheduling and memory management mechanisms required in a computer operating system for purposes other than producing thrashing. Such side effects are sometimes useful sometimes dysfunctional. Other theorists, often influenced by writings of Antonio Damasio argue that emotions themselves are necessary for any intelligent system (natural or artificial).

Some state that there is no empirical support for any generalization suggesting the antithesis between reason and emotion: indeed, anger or fear can often be thought of as a systematic response to observed facts. In any case, it is clear that the relation between logic and argument on the one hand and emotion on the other, is one which merits careful study.

Psychiatrist William Glasser's theory of the human control system states that behavior is composed of four simultaneous components: deeds, ideas, emotions, and physiological states. He asserts that we choose the idea and deed and that the associated emotions and physiological states also occur but cannot be chosen independently. He calls his construct a total behavior to distinguish it from the common concept of behavior. He uses the verbs to describe what is commonly seen as emotion. For example, he uses 'to depress' to describe the total behavior commonly known as depression which, to him, includes depressing ideas, actions, emotions, and physiological states. Dr. Glasser also further asserts that internal choices (conscious or unconscious) cause emotions instead of external stimuli.


Etymologically, the word emotion is a composite formed from two Latin words. e(x)/out, outward + motio/movement, action, gesture. This classical formation refers to the immediate nature of emotion as experienced by humans and attributed in some cultures and ways of thinking to all living organisms, and by scientific community to any creature that exhibits complex response traits similar to what humans refer to as emotion.

Theoretical traditions

According to Cornelius (1996), four main theoretical traditions have dominated research in emotions starting in the 1800's with Darwin's observations of emotion in man and animals. These traditions are not mutually exclusive and many researchers incorporate multiple perspectives in their work.

The Darwinian perspective

First articulated in the late 19th century by Charles Darwin[5], emotions evolved via natural selection and therefore have cross-culturally universal counterparts. Most research in this area has focused on physical displays of emotion including body language of animals and facial expressions in humans. Paul Ekman's work on basic emotions is representative of the Darwinian tradition.

The Jamesian perspective

William James in the 1800's believed that emotional experience is largely due to the experience of bodily changes. These changes might be visceral, postural, or facially expressive. However, the physiological aspects of his theory were empirically discredited by Walter Cannon in the second edition of Bodily Changes in Pain, Hunger, Fear and Rage.

The cognitive perspective

Many researchers believe that thought and in particular cognitive appraisal of the environment is an underlying causal explanation for emotional processes.

The social constructivist perspective

Social constructivism emphasizes the importance of culture and context in understanding what occurs in society and constructing knowledge based on this understanding (Derry, 1999; McMahon, 1997). Much current research in emotion is based on the social constructivist view.

The neurological tradition (Plutchik, 1980)

This tradition draws on recent work on neurophysiology and neuroanatomy to explain the nature of emotions. Joseph LeDoux (1986) reviews relatively current knowledge on the neurophysiology of emotion.


One of the most influential classification approaches in the study of emotion is Robert Plutchik's eight primary emotions. These consist of anger, fear, sadness, disgust, surprise, curiosity, acceptance, and joy. Like primary colors, primary emotions are believed to blend together to form the full spectrum of human emotional experience. Plutchik makes an evolutionary argument for the primacy of these eight by showing that each is related to behavior with survival value (e.g. fear motivates flight, anger motivates fighting). They are considered to be part of our biological heritage and built into human nature.

Paul Ekman devised a similar list of basic emotions from cross cultural research on the Fore tribesmen of Papua New Guinea. His finding that even an isolated, stone age culture can reliably identify the emotional expressions of fear, anger, happiness, sadness, and disgust lends further support to the view that at least some emotions are primary, innate, and universal in all human beings.[6]

Physical responses

The body frequently responds to Shame by warmth in the upper chest and face, Fear by a heightened heartbeat, increased "flinch" response, and increased muscle tension. The sensations connected with anger are nearly indistinguishable from fear. Happiness is often felt as an expansive or swelling feeling in the chest and the sensation of lightness or buoyancy, as if standing underwater. Sadness by a feeling of tightness in the throat and eyes, and relaxation in the arms and legs. Desire can be accompanied by a dry throat and heavy breathing.

In the psychotherapy field, advocates of Re-evaluation Counseling claim that painful emotion is best relieved via the well-known (and sometimes automatic) discharge processes of crying, laughing, sweating, shaking and trembling.[7]


Based on discoveries made through neural mapping of the limbic system, the neurobiological explanation of human emotion is that emotion is a pleasant or unpleasant mental state organized in the limbic system of the mammalian brain. Specifically, these states are manifestations of non-verbally expressed feelings of agreement, amusement, anger, certainty, control, disagreement, disgust, disliking, embarrassment, fear, guilt, happiness, hate, interest, liking, love, sadness, shame, surprise, and uncertainty. Emotions are mammalian elaborations of vertebrate arousal patterns, in which neurochemicals (e.g., dopamine, noradrenaline, and serotonin) step-up or step-down the brain's activity level, as visible in body movements, gestures, and postures. In mammals, primates, and human beings, feelings are displayed as emotion cues.

The human emotion of love is believed to have evolved from paleocircuits of the mammalian brain (specifically, modules of the cingulated gyrus) designed for the care, feeding, and grooming of offspring. Paleocircuits are neural platforms for bodily expression configured millions of years before the advent of cortical circuits for speech. They consist of pre-configured pathways or networks of nerve cells in the forebrain, brain stem and spinal cord. They evolved in the earliest mammalian ancestors, the jawless fishes, to control motor function.

Before the mammalian brain, life in the non-verbal world was automatic, preconscious, and predictable. Reptilian motor centers reacted to vision, sound, touch, chemical, gravity, and motion sensory cues with preset body movements and programmed postures. With the arrival of night-active mammals, circa 180 million years ago, smell replaced sight as the dominant sense, and a newer, more flexible way of responding—based on emotion and emotional memory—arose from the olfactory sense. In the Jurassic Period, the mammalian brain invested heavily in aroma circuits to succeed at night as reptiles slept. These odor pathways gradually formed the neural blueprint for what was later to become our limbic brain.

Primary (i.e., innate) emotions, such as fear, "depend on limbic system circuitry," with the amygdala and anterior cingulate gyrus being "key players."

Secondary emotions (i.e., feelings attached to objects [e.g., to dental drills], events, and situations through learning) require additional input from the prefrontal and somatosensory cortices. The stimulus may still be processed directly via the amygdala but is now also analyzed in the thought process. Thoughts and emotions are interwoven: every thought, however bland, almost always carries with it some emotional undertone, however subtle.

  • Smell carries directly to limbic areas of the mammalian brain via nerves running from the olfactory bulbs to the septum, amygdala, and hippocampus. In the aquatic brain, olfaction was critical for detecting food, foes, and mates from a distance in murky waters.
  • An emotional feeling, like an aroma, has a volatile or "thin-skinned" quality because sensory cells lie on the exposed exterior of the olfactory epithelium (i.e., on the bodily surface itself).
  • A sudden scent, like a whiff of smelling salts, may jolt the mind. The force of a mood is reminiscent of a smells intensity (e.g., soft and gentle, pungent, or overpowering), and similarly permeates and fades as well. The design of emotion cues, in tandem with the forebrains olfactory prehistory, suggests that the sense of smell is the neurological model for our emotions.

Like aromas, emotions are either positive or negative (i.e., pleasant or unpleasant)—and rarely neutral. Like odors, feelings come and go, defy logic, and clearly show upon our face in mood signs. It is likely that many emotions evolved from aroma paleocircuits a. in subcortical nuclei (e.g., the paleocortex of the amygdala), and b. in layers of nerve cells within the forebrains outer covering of neocortex. The latter's stratified architecture resembles that of the olfactory bulb, which is organized in layers as well.

Brain areas related to emotion

Emotions are thought to be related to activity in brain areas that direct our attention, motivate our behavior, and determine the significance of what is going on around us. Pioneering work by Broca (1878), Papez (1937), and MacLean (1952) suggested that emotion is related to a group of structures in the center of the brain called the limbic system, which includes the hypothalamus, cingulate cortex, hippocampi, and other structures. More recent research has shown that some of these limbic structures are not as directly related to emotion as others, while some non-limbic structures have been found to be of greater emotional relevance. The following brain structures are currently thought to be most involved in emotion:

  • Amygdala—The amygdalae are two small, round structures located anterior to the hippocampi near the temporal poles. The amygdalae are involved in detecting and learning what parts of our surroundings are important and have emotional significance. They are critical for the production of emotion, and may be particularly so for negative emotions, especially fear.
  • Prefrontal cortex—The term prefrontal cortex refers to the very front of the brain, behind the forehead and above the eyes. It appears to play a critical role in the regulation of emotion and behavior by anticipating the consequences of our actions. The prefrontal cortex may play an important role in delayed gratification by maintaining emotions over time and organizing behavior toward specific goals.
  • Anterior cingulate—The anterior cingulate cortex (ACC) is located in the middle of the brain, just behind the prefrontal cortex. The ACC is thought to play a central role in attention, and may be particularly important with regard to conscious, subjective emotional awareness. This region of the brain may also play an important role in the initiation of motivated behavior.
  • Ventral striatum—The ventral striatum is a group of subcortical structures thought to play an important role in emotion and behavior. One part of the ventral striatum called the nucleus accumbens is thought to be involved in the experience of goal-directed positive emotion. Individuals with addictions experience increased activity in this area when they encounter the object of their addiction.
  • Insula—The insular cortex is thought to play a critical role in the bodily experience of emotion, as it is connected to other brain structures that regulate the body’s autonomic functions (heart rate, breathing, digestion, etc.). This region also processes taste information and is thought to play an important role in experiencing the emotion of disgust.

Computer models of emotion

A flurry of recent work in modeling emotional circuitry and recognition has come out of computer science, engineering, psychology and neuroscience (c.f. Fellous, Armony & LeDoux, 2002).

  • See affective computing
  • Neural network models of emotion recognition

Emotion in animals

There is increasing support for animals having emotions, although it is still not clear to what amount those are qualitatively the same as human's feelings.

Sociology of Emotions

Neuroscientist Antonio Damasio has shown emotions to be essential for human social life. Rational, reasonable, or otherwise effective choosing or decision making are all about differentially valuing, and valuing is based on comparing emotional worth attributed to, and expected from the available alternatives of action – as much as on feelings of confidence or uncertainty in our stimation skills. Affect and logic are social competences and their participation in decision making varies widely among individuals, situations and cultures.

Sociologist Randall Collins has stated that a single, specific and long-term emotion named emotional energy is the main motivating force in social life, for love and hatred, investing, working or consuming, rendering cult or waging war. Individually, emotional energy ranges from the highests heights of enthusiasm, self-confidence and initiative to the deepest depths of apathy, depression and retreat. But this does not make it just a psychological emotion.

Emotional energy comes from variously successful or failed chains of interaction rituals, that is, patterned social encounters –from conversation or sexual flirtation through Christmas family dinners or office work to mass demonstrations, organizations or revolutions. In the latter, the coupling of participants' behavior synchronizes their nervous systems to the point of generating a collective effervescence, one observable in their mutual focus and emotional entraining, as well as in their loading of emotional and symbolic meaning to entities which subsequently become emblems of the ritual and of the membership group endorsing, preserving, promoting and defending them. Thus social life would be most importantly about generating and distributing emotional energy. Recent research has shown that most areas of social dynamics revolve around some particular emotional cluster. Most significant is classic contribution by Thomas J. Scheff, who established that many cases of social conflict are based on a destructive and often escalating, but stoppable and reversible shame-rage cycle: when someone results or feels shamed by another, their social bond comes under stress.

This can be cooperatively acknowledged, talked about and – most effectively when possible - laughed at so their social bond may be restored. Yet, when shame is not acknowledged, but instead negated and repressed, it becomes rage, and rage may drive to aggressive and shaming actions that feed-back negatively on this self-destructive situation. The social management of emotions might be the fundamental dynamics of social cooperation and conflict around resources, complexity, conflict and moral life.

References and notes

  1. Masters, Robert (2000), Compassionate Wrath: Transpersonal Approaches to Anger
  2. Damasio, Antonio (1994) Descartes Error Penguin Putnam, New York, New York
  3. Emotional Competency discussion of emotion
  4. Sloman, Aaron (1981) Why Robots Will Have Emotions. In proc.[1]. University of Sussex, UK
  5. Darwin, Charles (1872). The Expression of Emotions in Man and Animals. Note: This book was originally published in 1872, but has been reprinted many times thereafter by different publishers
  6. Ekman, P. & Friesen, W. V (1969). The repertoire of nonverbal behavior: Categories, origins, usage, and encoding. Semiotica, 1, 49-98.
  7. Counseling recovery processes - RC website
  1. Arbib, M. and Fellous, J-M (editors). (2005) Who Needs Emotions?: The Brain Meets the Robot. Oxford, New York: Oxford University Press.
  2. Cornelius, R. (1996). The science of emotion. New Jersey: Prentice Hall.
  3. Ekman P. (1999). "Facial Expressions" in Handbook of Cognition and Emotion. Dalgleish T & Power M, Eds. John Wiley & Sons Ltd. New York, New York.
  4. Fellous, J.M., Armony, J.L., & LeDoux, J.E. (2002). "Emotional Circuits and Computational Neuroscience" in 'The handbook of brain theory and neural networks' Second Edition. M.A. Arbib (editor), The MIT Press. [2]
  5. Frijda, Nico H. (1986). The Emotions. Maison des Sciences de l'Homme and Cambridge University Press. [3]
  6. LeDoux, J.E. (1986). The neurobiology of emotion. Chap. 15 in J E. LeDoux & W. Hirst (Eds.) Mind and Brain: diologues in cognitive neuroscience. New York: Cambridge.
  7. Plutchik, R. (1980). A general psychoevolutionary theory of emotion. In R. Plutchik & H. Kellerman (Eds.), Emotion: Theory, research, and experience: Vol. 1. Theories of emotion (pp. 3-33). New York: Academic.

Emotion researchers

Institution/ Research Center

See also

  • Affective neuroscience
  • Affective science
  • Emotional dysregulation—as in a borderline personality
  • Emotion and memory
  • List of emotions
  • Empathy
  • Emotional bias
  • Emotional distance
  • Descartes' Error

External links


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