The James–Lange theory refers to a hypothesis on the origin and nature of emotions and is one of the earliest theories of emotion within modern psychology. It was developed independently by two 19th-century scholars, William James and Carl Lange. The basic premise of the theory is that physiological arousal instigates the experience of a specific emotion. Instead of feeling an emotion and subsequent physiological (bodily) response, the theory proposes that the physiological change is primary, and emotion is then experienced when the brain reacts to the information received via the body's nervous system.
The theory has been criticised and modified over the course of time, as one of several competing theories. In 2002 a research paper on the autonomous nervous system stated that the theory has been "hard to disprove".
The theory states that all emotion is derived from the presence of a stimulus, which evokes a physiological response, such as muscular tension, a rise in heart rate, perspiration, and dryness of mouth. This physical arousal makes a person feel a specific emotion. According to this theory, emotion is a secondary feeling, indirectly caused by the primary feeling, which is the physiological response caused by the presence of a stimulus. The specific pathway involved in the experience of emotion was also described by James. He stated that an object has an effect on a sense organ, which relays the information it is receiving to the cortex. The brain then sends this information to the muscles and viscera, which causes them to respond. Finally, impulses from the muscles and viscera are sent back to the cortex, transforming the object from an "object-simply apprehended" to an "object-emotionally felt."
James explained that his theory went against common sense. For example, while most would think the order of emotional experience would be that a person sees a bear, becomes afraid, and runs away, James thought that first the person has a physiological response to the bear, such as trembling, and then becomes afraid and runs. According to James, the physiological response comes first, and it is followed by an emotion and a reaction. James believed that these responses were "reflex type" reactions which are built in: "Instinctive reactions and emotional expressions shade imperceptibly into each other. Every object that excites an instinct excites an emotion as well."
James vs. Lange 
Both theorists defined emotion as a feeling of physiological changes due to a stimulus, however the theorists focused on different aspects of emotion. Although James did talk about the physiology associated with an emotion, he was more focused on conscious emotion and the conscious experience of emotion. For example, a person who is crying reasons that he must be sad. Lange reinterpreted James's theory by operationalizing it. He made James's theory more testable and applicable to real life examples. However, both agreed that if physiological sensations could be removed, there would be no emotional experience. In other words, physiological arousal causes emotion.
Since the theory's inception, scientists have found evidence that not all aspects of the theory are relevant and true. The theory was challenged in the 1920s by psychologists such as Walter Cannon and Philip Bard, who theorized that physiological changes are caused by emotions, which is essentially the opposite of the James–Lange Theory (collectively known as the Cannon–Bard theory of emotion). The third theory of emotion is Schachter and Singer's two factor theory of emotion. This theory states that cognitions are used to interpret the meaning of physiological reactions to outside events.
Cannon emphasized that the viscera can be separated from the central nervous system and have no impact on emotion. This contradicts the James–Lange theory because James believed that the viscera is the center of emotion. Cannon examined research performed by Sherrington, who separated the spinal cord and vagus nerves from all connections in the rest of the body, and found that the experience of emotion did not change, thus disproving the idea that the viscera has a major impact on emotion.
Cannon also emphasized that visceral responses occur when experiencing many different emotions, and in the absence of emotion. For example, the same visceral responses such as increased heart rate, sweating, widening of the pupils, and the discharge of adrenaline can be associated with the experience of fear or anger. However, they are also connected to conditions such as fever, feeling cold, and having difficulty breathing. Therefore, the physical responses are too general to be linked to a specific emotion.
The visceral responses are slow and not sensitive enough to elicit the emotional response James is thinking of. J.N. Langley has shown that there is a period of two to four seconds between when the chorda tympani nerve is stimulated and when the salivary gland associated with this nerve responds. There seems to be too much of a delay between the stimulation of the viscera and the physiological response for it to be associated with an emotion.
Also, stimulating the viscera to produce a specific emotion has been proven to be ineffective by a scientist named Gregorio Marañon. In one study by him, participants had adrenalin injected into their veins, which produced physiological changes expected to be linked with an emotion. However, the emotion was never produced. The only noticeable changes in the participants were physical, such as activation of the sympathetic nerve impulse, which creates constriction of the blood vessels and dilation of the bronchioles. This study disproves the idea that physiological responses are the sole reason for the experience of emotion.
A double dissociation has been found for autonomic nervous system responses between those with injuries to the ventromedial prefrontal cortex that have the feelings not the responses, and those with injuries to the right somatosensory cortex that lack the feelings but not the responses.
The theory has also faced some controversy more recently, by scientists such as Lisa Feldman Barrett and James Gross. One of the issues Barrett points out is that when testing this theory with electrical stimulation, there is not a one to one response between a behavior and emotion category. In other words "stimulation of the same site produces different mental states across instances, depending on the prior state of the individual and also the immediate context." This conclusion means there is more going on when a person feels an emotion than just a physiological response. Some kind of processing must happen between the physiological response and the perception of the emotion.
Barrett also points out the idea that the experience of emotion is subjective. There is no way to decipher whether a person is feeling sad, angry, or otherwise without relying on the person's perception of emotion. Also, humans do not always exhibit emotions using the same behaviors; humans may withdraw when angry, or fight out of fear. It takes more than a physiological response for a human to exhibit an emotion. According to Barrett, a person must make meaning of the physical response based on context, prior experience, and social cues, before he knows what emotion is attached to the situation. It is more than the physical sensation that determines an emotion. It is really a variety of factors which come together to form the experience of an emotion, therefore it is not as simple as James and Lange proposed. It can be said that emotion is related to the perceiver and his culture because culture shapes experience, and it will ultimately shape the person's perception of the emotion. Said simply "an emotion is more than just a particular pattern of objective changes that reflect a diagnostic body state or a physical action-its reality derives from the way perception works in a human mind, in conjunction with other human minds."
In an article by Gross and Barrett, emotion is defined as "a collection of psychological states that include subjective experience, expressive behavior, and peripheral physiological responses." Gross discusses four different perspectives on emotion and how it is formed. The Basic Emotion models describe emotion as something which cannot be broken down into anything simpler. Emotion is derived from a circuit in the brain which produce the experiences associated with emotion including behavior, facial expressions, and physical responses. Appraisal models of emotion indicate that an emotion is just a set of response tendencies which help humans relate to the world. Psychological construction models of emotion dictate that emotion is the result of psychological constructs. One emotion could cause a variation of behavioral responses, so according to this model, emotions are more than psychological constructs because they could lead to many different outcomes. Social construction models of emotion describe emotions as the result of culture. Culture determines whether or not a reaction is considered an emotion or just a simple reaction. Gross and Barrett go to such great lengths to describe the different perspectives on emotion to demonstrate that the James–Lange theory is just one idea about how emotions occur and that there are many other possibilities.
- Cannon, Walter (December 1927). "The James-Lange Theory of Emotions: A Critical Examination and an Alternative Theory". The American Journal of Psychology 39: 106–124.
- William, James. Discussion. The Physical Basis of Emotion. pp. 516–529.
- Ellsworth, P. C. (1994). William James and Emotion: Is a Century of Fame Worth a Century of Misunderstanding?. Psychological Review, (101)2, 222–229.
- Lang, Peter J. (1994). "The Varieties of Emotional Experience: A Meditation on James–Lange Theory". Psychological Review 101 (2): 211–221.
- Johnsen EL, Tranel D, Lutgendorf S, Adolphs R. (2009). A neuroanatomical dissociation for emotion induced by music. Int J Psychophysiol. 72(1):24–33. doi:10.1016/j.ijpsycho.2008.03.011 PMID 18824047
- Feldman Barrett, Lisa (2012). "Emotions are Real". American Psychological Association 12 (3): 413–429.
- Gross, James J.; Lisa Feldman Barrett (2011). "Emotion Generation and Emotion Regulation: One or Two Depends on Your Point of View". Emotion Review 3 (1): 8–16.