Psychologists and behaviorists have been proposing theories on human emotion for much of the modern era. Emotions are considered to be inner feelings or states of mind that are associated with a physical change and are expressed by an outward behavior. In the scientific world, experts attempt to discover which comes first: the mental feeling, the physical change or the outward behavior.
History
The idea of theories of emotion can be traced back to the Ancient Greeks and the cultural explosion of the Iron Age. The Stoics, Plato and Aristotle all had their own ideas about how human emotions work. The later works of scientists like Descartes and Spinoza in the 17th century and Hume in the 18th century also show complex theories of emotion. By the 19th century, empirical research began to improve and some of the more widely accepted emotional theories were created. Two of the best-known theories of the time were established by William James and Carl Lange, and Walter Cannon and Philip Bard. In the early 20th century, other theorists like Magda B. Arnold, Richard Lazarus and Robert Plutchik added greatly to the field, which began to flourish.
Function
Theories of emotion are largely concerned with the relationship between the emotion itself and the results of the emotion. By establishing why and how an emotion occurs and leads to a result, scientists can better understand human behavior. Emotion often rules the way that humans live; usually some emotions encourage positive behaviors and some stressful emotions lead to negative behaviors. Emotions can have helpful or harmful effects on human physiology, such as in the case of anxiety leading to or aggravating a number of health problems like gastrointestinal disorders and headaches.
Types
Most theories of emotion fit into one of two categories: cognitive and non-cognitive. Cognitive theories assert that emotion comes from the prefrontal cortex, while non-cognitive theories describe emotions as instinctual, coming from the amygdala. Theories of emotion are also divided into categories based on what order they state emotional experiences occur in. Some theories, such as the James-Lange theory and the Schacter-Singer theory, state that people experience physiological arousal before the emotional reaction to an event occurs. Other theories, like the Lazarus theory, assert that physiological arousal occurs after or at the same time as the emotional reaction.
Features
The most well-known theories of emotion share some things in common, but usually differ on the specifics. The James-Lange theory of emotion and the Schacter-Singer theory of emotion both give the order of emotional experience as an event followed by physiological arousal, which is then followed by an interpretation of the event's relationship to the arousal and an emotional reaction. However, the James-Lange theory explains that the physical changes cause the emotions while the Schacter-Singer theory describes emotions as a direct result of the interpretation. Another major theory, the Cannon-Bard theory, states that arousal and emotional response occur at the same time following an even. The Lazarus theory also pairs arousal and emotion together, but adds an interpretation step after the event.
Considerations
All of the classic theories of emotion have fallen under criticism at various times, though many modern theorists still use them as a basis to work from. Some more recent theories are the affective events theory, which explores time as it is related to the influence on behavior of emotional reaction to events, and the modern cognitive theories, many of which connect interpretation to emotional response. Neurobiological theories explore human emotion by describing the evolution of the limbic system in many different animals, taking the physiology as the root of emotional reaction.
