Functional Smiles: Tools for Love, Sympathy, and War

Abstract

(up to 150 words)The smile is the most frequent facial expression, but not all smiles are equal. A social functional account holds that smiles of reward, affiliation, and dominance resolve basic social tasks, including rewarding behavior, social bonding, and hierarchy negotiation.Here we explore facial expression patterns associated with the three smiles. We modeled the expressions using a data-driven approach and showed that reward smiles are symmetrical and accompanied by eyebrow raising, affiliative smiles involve lip pressing, and asymmetrical dominance smiles contain nose wrinkling and upper lip raising. A Bayesian classifier analysis and a detection task revealed that the three smile types are highly distinct facial expressions. Finally, social judgments made by a separate participant group showed that the different smile type models convey different social messages. Our results provide the first detailed description of the physical form and social messages conveyed by the three functional smiles, documenting the versatility of these facial expressions.

Mimicking and sharing emotions: a re-examination of the link between facial mimicry and emotional contagion

“…These results are in line with the notion that, when provided with no additional information about the senders, people typically react to smiles with matching emotional expressions because smiles, in general, signal affiliative intentions (Fischer & Hess, 2017). This refers in particular to smiles representing basic expressions of happiness because such expressions are indicative of psychological closeness and approach motivation (Rychlowska et al, 2017). What our results add to this observation is that such smiles may also elicit happy feelings in the receiver through facial muscle activity, thereby supporting the core assumption of the emotional contagion theory (Hatfield et al, 1994;Prochazkova & Kret, 2017).…”

Uncovering mental representations of smiled speech using reverse correlation

“…The present paradigm could be used to study other acoustical facets of smiled speech [e.g., are different types of smiles related to different representations, as is the case in vision? (Rychlowska et al, 2017)], but also to explore the bases of other social or articulatory traits, and investigate whether other vocal gestures of lesser emotional or adaptive relevance are processed through similarly robust and consistent perceptual filters. The present paper suggests a general framework 4 to estimate the spectral bases of any high-level representation of speech, i.e., not only smiled speech, but any emotional/ social/paralinguistic aspect of speech timbre.…”

Behavioral and Physiological Responses to Visual Interest and Appraisals: Multimodal Analysis and Automatic Recognition

“…Smiling is one indicator of interest in our experimental framework, but is not the only one nor the most defining. Smiling is not a simple behavior that reflects one genuine emotion, but a powerful behavior that can have multiple social and emotional functions (e.g., Rychlowska et al, 2017). For example, smiling can be the expression of other positive emotions, or be used to foster bonding or dominance.…”