Smiles

Smiles
Name	Smiles

Contents

Smiles are facial expressions characterized by the curvature of the mouth and activation of facial muscles associated with positive affect, often studied across disciplines including psychology, neuroscience, ethology, anthropology, and sociology. Research spans figures and institutions such as Charles Darwin, Sigmund Freud, Paul Ekman, Origin of Species-era observers, and modern labs at Harvard University, Stanford University, and Max Planck Society. Smiles appear in literature, visual arts, cinema, and public life involving people like Leonardo da Vinci, Marilyn Monroe, Nelson Mandela, Queen Elizabeth II, and institutions such as the Museum of Modern Art, BBC, and The New York Times.

Etymology and terminology

The linguistic roots of smiling are traced in philological work by scholars at Oxford University Press, Cambridge University Press, and lexicographers influenced by Samuel Johnson and Noah Webster, while terminology evolved across scholarly networks including the Linguistic Society of America and the Royal Society of London. Historical accounts reference observers like Charles Darwin and The Expression of the Emotions in Man and Animals alongside Gustav Le Bon and social theorists such as Émile Durkheim and Max Weber who commented on facial expression as social signal. Clinical nomenclature emerges from classification systems produced by organizations like the American Psychiatric Association and diagnostic manuals used at Mayo Clinic and Cleveland Clinic.

Researchers including Paul Ekman, Carroll Izard, Silvan Tomkins, and teams at University of California, Berkeley and University College London distinguish Duchenne and non-Duchenne smiles, linking orbicularis oculi activation to perceived genuineness. Anatomy texts from Gray's Anatomy and studies at Johns Hopkins University identify muscles such as the zygomaticus major and risorius, and neural control pathways implicating structures like the motor cortex, amygdala, basal ganglia, and facial nerve (cranial nerve VII) discussed in seminars at Society for Neuroscience. Comparative work by researchers at Primate Research Institute, Kyoto University and Max Planck Institute for Evolutionary Anthropology compares human smiles to displays in common chimpanzee studies, bonobo behavior, and avian social signaling in fieldwork associated with National Geographic Society.

Theories from Paul Ekman, William James, Stanley Schachter, and Albert Bandura articulate roles for smiles in emotion communication, self-regulation, and social learning documented in research at Columbia University, Yale University, and University of Chicago. Social signaling models incorporate findings from experiments at MIT Media Lab, Princeton University, and London School of Economics on trust games, negotiation studies influenced by John Nash-related game theory, and work on impression management referencing Erving Goffman. Smiles mediate affiliation across contexts studied by organizations like World Health Organization in public-health campaigns and by NGOs such as Amnesty International and Red Cross in humanitarian communication strategies.

Cross-cultural studies by Ekman and teams at University of California, San Francisco, and anthropologists associated with American Anthropological Association document variation in smile norms across societies including Japan, United States, Russia, Brazil, India, Nigeria, Mexico, China, France, and Germany. Symbolic meanings appear in art history featuring creators like Vincent van Gogh, Pablo Picasso, Andy Warhol, and photographers from Magnum Photos, and in filmography involving directors such as Alfred Hitchcock, Federico Fellini, and Akira Kurosawa. Political rhetoric uses smiles in campaigns by figures like Barack Obama, Margaret Thatcher, Vladimir Putin, and in state portraiture of leaders including Abraham Lincoln and Mahatma Gandhi.

Developmental psychology research by Jean Piaget, Lev Vygotsky, Mary Ainsworth, and John Bowlby explores infant smiling, social referencing, and attachment processes investigated at Harvard University, University of Pennsylvania, and University of Oxford. Studies document neonatal social smiling, stranger anxiety contexts in toddlerhood observed in longitudinal cohorts at Duke University and University of Michigan, and adolescent peer interaction research at University of Toronto and Imperial College London. Gerontology research from National Institute on Aging and King's College London examines changes in expressivity among older adults and in dementia care settings like facilities run by Alzheimer's Association.

Clinical neurology and psychiatry literature from Johns Hopkins Hospital, Massachusetts General Hospital, and Royal Free Hospital address dysarthria, facial palsy, and conditions such as Bell's palsy, Parkinson's disease, stroke, and frontotemporal dementia that alter smiling. Neuroimaging studies at National Institutes of Health, Karolinska Institute, and Institut Pasteur use fMRI and PET to map smile-related circuits involving the prefrontal cortex, insula, and ventral striatum. Therapeutic interventions developed by teams at Stanford University School of Medicine and University College London Hospitals include neuromuscular retraining, botulinum toxin research involving Allergan-sponsored trials, and psychosocial treatments cited in guidelines by World Psychiatric Association.

Category:Nonverbal communication