title: What's in a smile?
abstract: In positive social contexts, both adults and older infants show more Duchenne smiling (which involves high cheek raising) than non-Duchenne smiling (which does not). This study compared Duchenne and non-Duchenne smiles in early infancy for clues to their emotional significance. Infants (N = 13) from 1 to 6 months of age were videotaped weekly for 5 min in 208 face-to-face interactions with their mothers. Levels of Duchenne and non-Duchenne smiling were correlated within interactive sessions, and the 2 smiles had similar developmental trajectories. Duchenne smiles were typically preceded by non-Duchenne smiles. The results suggest these frequently contrasted types of smiles occur in similar situations and are often different temporal phases of a continuous emotional process. In contrast to adults, infant Duchenne smiles had longer durations than non-Duchenne smiles, suggesting infant smiling does not fit adult models of emotional functioning.
authors.affiliation: Department of Psychology, University of Miami, Coral Gables, Florida 33101-0721, USA. dmessinger@miami.edu
authors.forename: D S
authors.initials: DS
authors.lastname: Messinger
authors.forename: A
authors.initials: A
authors.lastname: Fogel
authors.forename: K L
authors.initials: KL
authors.lastname: Dickson
mesh_terms: D000339:Affect / Q000502:physiology; D005149:Facial Expression; D005152:Facial Muscles / Q000502:physiology; D005260:Female; D006801:Humans; D007223:Infant; D008137:Longitudinal Studies; D008297:Male; D012904:Smiling / Q000502:physiology*; D013997:Time Factors; D015050:Zygoma / Q000502:physiology