Affiliative zygomatic synchrony in co-present strangers.

Area of Science:

• Social Psychology
• Nonverbal Communication
• Affective Science

Background:

• Individuals often synchronize responses in social settings, influencing emotional and social states.
• Facial signals are key for interpersonal communication, yet facial synchrony remains understudied.
• Smiling is a primary facial signal with potential social functions.

Purpose of the Study:

• Investigate the social spread and affiliative function of smiling dynamics.
• Examine links between smiling synchrony and autonomic/emotional convergence.
• Assess smiling's role in facilitating affiliation between unacquainted individuals.

Main Methods:

• Measured moment-to-moment zygomatic electromyography and cardiovascular activity in dyads.
• Participants were previously unacquainted individuals co-viewing emotional movies.
• Assessed synchrony during movie viewing and subsequent self-reported affiliative feelings.

Main Results:

• Observed robust, dyad-specific zygomatic synchrony during co-viewing.
• Smiling synchrony correlated with cardiovascular synchrony and positive emotion convergence during a positive movie.
• Smiling synchrony predicted increased affiliative feelings between dyad members.

Conclusions:

• Naturally occurring smiling behavior is highly contagious.
• Smiling synchrony acts as a social facilitator, promoting affiliation.
• Synchronized facial expressions may enhance social bonding and emotional connection.