A smile is a facial expression formed primarily by flexing the muscles at the sides of the mouth. Some smiles include a contraction of the muscles at the corner of the eyes, an action known as a Duchenne smile. Among humans, a smile expresses delight, sociability, happiness, joy, or amusement. It is distinct from a similar but usually involuntary expression of anxiety known as a grimace. Although cross-cultural studies have shown that smiling is a means of communication throughout the world, there are large differences among different cultures, religions, and societies, with some using smiles to convey confusion, embarrassment or awkwardness.
A facial expression is one or more motions or positions of the muscles beneath the skin of the face. According to one set of controversial theories, these movements convey the emotional state of an individual to observers. Facial expressions are a form of nonverbal communication. They are a primary means of conveying social information between humans, but they also occur in most other mammals and some other animal species.
Paul Ekman is an American psychologist and professor emeritus at the University of California, San Francisco who is a pioneer in the study of emotions and their relation to facial expressions. He was ranked 59th out of the 100 most cited psychologists of the twentieth century. Ekman conducted seminal research on the specific biological correlations of specific emotions, attempting to demonstrate the universality and discreteness of emotions in a Darwinian approach.
A microexpression is a facial expression that only lasts for a short moment. It is the innate result of a voluntary and an involuntary emotional response occurring simultaneously and conflicting with one another, and occurs when the amygdala responds appropriately to the stimuli that the individual experiences and the individual wishes to conceal this specific emotion. This results in the individual very briefly displaying their true emotions followed by a false emotional reaction.
Amusement is the state of experiencing humorous and entertaining events or situations while the person or animal actively maintains the experience, and is associated with enjoyment, happiness, laughter and pleasure. It is an emotion with positive valence and high physiological arousal.
An emotional expression is a behavior that communicates an emotional state or attitude. It can be verbal or nonverbal, and can occur with or without self-awareness. Emotional expressions include facial movements like smiling or scowling, simple behaviors like crying, laughing, or saying "thank you," and more complex behaviors like writing a letter or giving a gift. Individuals have some conscious control of their emotional expressions; however, they need not have conscious awareness of their emotional or affective state in order to express emotion.
Emotionality is the observable behavioral and physiological component of emotion. It is a measure of a person's emotional reactivity to a stimulus. Most of these responses can be observed by other people, while some emotional responses can only be observed by the person experiencing them. Observable responses to emotion do not have a single meaning. A smile can be used to express happiness or anxiety, while a frown can communicate sadness or anger. Emotionality is often used by experimental psychology researchers to operationalize emotion in research studies.
The facial feedback hypothesis, rooted in the conjectures of Charles Darwin and William James, is that one's facial expression directly affects their emotional experience. Specifically, physiological activation of the facial regions associated with certain emotions holds a direct effect on the elicitation of such emotional states, and the lack of or inhibition of facial activation will result in the suppression of corresponding emotional states.
According to some theories, emotions are universal phenomena, albeit affected by culture. Emotions are "internal phenomena that can, but do not always, make themselves observable through expression and behavior". While some emotions are universal and are experienced in similar ways as a reaction to similar events across all cultures, other emotions show considerable cultural differences in their antecedent events, the way they are experienced, the reactions they provoke and the way they are perceived by the surrounding society. According to other theories, termed social constructionist, emotions are more deeply culturally influenced. The components of emotions are universal, but the patterns are social constructions. Some also theorize that culture is affected by the emotions of the people.
Discrete emotion theory is the claim that there is a small number of core emotions. For example, Silvan Tomkins concluded that there are nine basic affects which correspond with what we come to know as emotions: interest, enjoyment, surprise, distress, fear, anger, shame, dissmell and disgust. More recently, Carroll Izard at the University of Delaware factor analytically delineated 12 discrete emotions labeled: Interest, Joy, Surprise, Sadness, Anger, Disgust, Contempt, Self-Hostility, Fear, Shame, Shyness, and Guilt.
Emotion classification, the means by which one may distinguish or contrast one emotion from another, is a contested issue in emotion research and in affective science. Researchers have approached the classification of emotions from one of two fundamental viewpoints:
- that emotions are discrete and fundamentally different constructs
- that emotions can be characterized on a dimensional basis in groupings
Emotional responsivity is the ability to acknowledge an affective stimuli by exhibiting emotion. It is a sharp change of emotion according to a person's emotional state. Increased emotional responsivity refers to demonstrating more response to a stimulus. Reduced emotional responsivity refers to demonstrating less response to a stimulus. Any response exhibited after exposure to the stimulus, whether it is appropriate or not, would be considered as an emotional response. Although emotional responsivity applies to nonclinical populations, it is more typically associated with individuals with schizophrenia and autism.
Paula M. Niedenthal is a social psychologist currently working as a professor of psychology at the University of Wisconsin–Madison. She also completed her undergraduate studies at the University of Wisconsin at Madison where she received a Bachelor's in Psychology. She then received her Ph.D. at the University of Michigan before becoming a faculty member of the departments of Psychology at Johns Hopkins University and Indiana University. Until recently, she served as the Director of Research in the National Centre for Scientific Research at the Université Blaise Pascal in Clermont-Ferrand France. The majority of Niedenthal's research focuses on several levels of analysis of emotional processes, this would include emotion-cognition interaction and representational models of emotion. Niedenthal has authored more than 80 articles and chapters, and several books. Niedenthal is a fellow of the Society for Personality and Social Psychology.
The study of the evolution of emotions dates back to the 19th century. Evolution and natural selection has been applied to the study of human communication, mainly by Charles Darwin in his 1872 work, The Expression of the Emotions in Man and Animals. Darwin researched the expression of emotions in an effort to support his materialist theory of unguided evolution. He proposed that much like other traits found in animals, emotions apparently also evolved and were adapted over time. His work looked at not only facial expressions in animals and specifically humans, but attempted to point out parallels between behaviors in humans and other animals.
Facial electromyography (fEMG) refers to an electromyography (EMG) technique that measures muscle activity by detecting and amplifying the tiny electrical impulses that are generated by muscle fibers when they contract.
Non-verbal leakage is a form of non-verbal behavior that occurs when a person verbalizes one thing, but their body language indicates another, common forms of which include facial movements and hand-to-face gestures. The term "non-verbal leakage" got its origin in literature in 1968, leading to many subsequent studies on the topic throughout the 1970s, with related studies continuing today.
In humans, posture can provide a significant amount of important information through nonverbal communication. Psychological studies have also demonstrated the effects of body posture on emotions. This research can be traced back to Charles Darwin's studies of emotion and movement in humans and animals. Currently, many studies have shown that certain patterns of body movements are indicative of specific emotions. Researchers studied sign language and found that even non-sign language users can determine emotions from only hand movements. Another example is the fact that anger is characterized by forward whole body movement. The theories that guide research in this field are the self-validation or perception theory and the embodied emotion theory.
Emotion perception refers to the capacities and abilities of recognizing and identifying emotions in others, in addition to biological and physiological processes involved. Emotions are typically viewed as having three components: subjective experience, physical changes, and cognitive appraisal; emotion perception is the ability to make accurate decisions about another's subjective experience by interpreting their physical changes through sensory systems responsible for converting these observed changes into mental representations. The ability to perceive emotion is believed to be both innate and subject to environmental influence and is also a critical component in social interactions. How emotion is experienced and interpreted depends on how it is perceived. Likewise, how emotion is perceived is dependent on past experiences and interpretations. Emotion can be accurately perceived in humans. Emotions can be perceived visually, audibly, through smell and also through bodily sensations and this process is believed to be different from the perception of non-emotional material.
A functional account of emotions posits that emotions facilitate adaptive responses to environmental challenges. In other words, emotions are systems that respond to environmental input, such as a social or physical challenge, and produce adaptive output, such as a particular behavior. Under such accounts, emotions can manifest in maladaptive feelings and behaviors, but they are largely beneficial insofar as they inform and prepare individuals to respond to environmental challenges, and play a crucial role in structuring social interactions and relationships.
Fritz Strack is a German social psychologist and professor emeritus at the University of Würzburg. Strack is a member of Germany's National Academy of Sciences Leopoldina and was awarded the Ig Nobel Prize for psychology in 2019.
