Being facially expressive is socially advantageous

Abstract

Individuals vary in how they move their faces in everyday social interactions. In a first large-scale study, we measured variation in dynamic facial behaviour during social interaction and examined dyadic outcomes and impression formation. In Study 1, we recorded semi-structured video calls with 52 participants interacting with a confederate across various everyday contexts. Video clips were rated by 176 independent participants. In Study 2, we examined video calls of 1315 participants engaging in unstructured video-call interactions. Facial expressivity indices were extracted using automated Facial Action Coding Scheme analysis and measures of personality and partner impressions were obtained by self-report. Facial expressivity varied considerably across participants, but little across contexts, social partners or time. In Study 1, more facially expressive participants were more well-liked, agreeable, and successful at negotiating (if also more agreeable). Participants who were more facially competent, readable, and perceived as readable were also more well-liked. In Study 2, we replicated the findings that facial expressivity was associated with agreeableness and liking by their social partner, and additionally found it to be associated with extraversion and neuroticism. Findings suggest that facial behaviour is a stable individual difference that proffers social advantages, pointing towards an affiliative, adaptive function.

Facial expressivity in dominant macaques is linked to group cohesion

“…In humans, we have emerging evidence which suggests that stable inter-individual differences in facial expressivity can directly impact the outcome of their social interactions. More specifically, more facially expressive people (those with more facial movement and higher diversity of movement) tend to be rated as more likeable both by third parties [ 20 ] and by their direct social partners [ 21 ] and can better negotiate resources in their favour [ 21 ]. The reasons why we perceive facially expressive people as more likeable have yet to be fully explored, but one suggestion is that the increased readability of a facially expressive partner signals honesty, which is considered a valuable trait in a social partner [ 19 ].…”