Emotions and motivation, words derived from the same Latin root, are often linked in psychology, and both are primary drivers in how people behave. Psychology defines emotion as the sum of a person’s mental and physical state in response to a particular situation. Emotions may often feel as if they’re a mysterious, sometimes unwelcome part of human experience that occur only in the mind. But they are rooted in our species’ evolution, and involve a complex interaction between one’s body, brain and the environment.
Evolution and the Brain
When inputs from the external world combine with physiological reactions within the body, emotions result. Emotional processing developed in humans’ evolutionary history in the brain’s subconscious limbic system, a region in the inner margin of the upper brain composed of parts associated with instinctual needs and responses such as fear, aggression, thirst, sexual drive and motivation. According to some neuroscientists, this basic architecture of the brain means we are wired to feel first and think second, as for example with the well-known “fight or flight” instinct.
Early Theories of Emotion
Psychologists in the late 19th and early 20th centuries focused on these evolutionary aspects of emotions. Previous theories of emotion held that after experiencing an environmental stimulus, we experience emotion first, then a physical reaction. Developed independently by psychologist William James and physiologist Carl Lange, the James-Lange theory stated on the contrary that humans experience a physiological reaction first, and that causes them to experience something they label as a certain “emotion”; emotion and physical arousal occur essentially simultaneously.
In the 1960’s, psychologists started noticing that physiological reactions to emotions are similar regardless of which emotion a person is experiencing. Some kind of cognitive mediation must occur that causes people to label physical reactions as one emotion over another. As neuroscientist Joseph LeDoux summarized it, an individual’s mental interpretation of ambiguous physical sensations is, at least in part, what produces “feelings.” Now known as “appraisal theory,” this focus on the cognitive as well as physical aspects of emotion is one of the leading frameworks for understanding emotions today. Its basic premise is that emotions are not caused by situations themselves, but how we interpret a situation, explaining why people experiencing almost identical situations can feel very different things.
Neuroscientists and Geneticists Weigh In
In the 21st century, cognitive neuroscientists and genetic epidemiologists also started shedding significant light on how peoples’ inborn brain circuitry and DNA impact emotions and our ability to manage them. Researchers have been able to demonstrate how specific genotypes, combined with neural processing, can predispose some people toward things like depression. Some individuals’ inherent brain circuitry and DNA bias them toward interpreting personal circumstances negatively more often than positively, resulting in emotional vulnerability. Other people, though, are naturally wired to be emotionally resilient.
The role one’s environment plays in emotional experience also has gained greater focus. Ecological perspectives view people as products of an interaction between themselves and their unique social system, including their family environment. Emotional disturbance, according to this view, results from a clash between the transactions occurring between a person and his or her environment. Similarly, the biosocial theory, prevalent among mental health practitioners, holds that the ability to regulate emotion comes from the interplay between biological disposition and environmental context, particularly during childhood development. Cultural values and norms also impact emotion -- for example, in the U.S. happiness is often linked to individual circumstances, achievements and events while in Japan, positive feelings are more often associated with membership in groups, closeness to others, and mutual respect.