Blocking mimicry makes true and false smiles look the same.

Area of Science:

• Psychology
• Cognitive Neuroscience
• Social Psychology

Background:

• Facial mimicry, the automatic imitation of observed facial expressions, is hypothesized to play a role in social cognition.
• Accurate interpretation of subtle facial expressions, such as genuine versus posed smiles, is vital for social interaction.

Purpose of the Study:

• To investigate the causal role of facial mimicry in judging the genuineness of true and false smiles.
• To determine if inhibiting facial mimicry affects the ability to differentiate between authentic and non-authentic facial expressions.

Main Methods:

• Three experiments were conducted, manipulating facial mimicry using a novel mouthguard technique.
• Facial electromyography (EMG) measured facial reactions.
• Participants rated the genuineness of true and false smiles under conditions of blocked mimicry, free mimicry, and mimicry with distraction (squeeze ball, heart rate monitor).

Main Results:

• A novel mouthguard technique effectively blocked facial mimicry, altering both the amount and timing of facial reactions.
• Inhibition of facial mimicry led to a compromised ability to discriminate between true and false smiles.
• Smiles were judged as equally genuine when mimicry was blocked, regardless of whether they were true or false.

Conclusions:

• Facial mimicry is essential for the accurate decoding of subtle facial expressions, particularly smiles.
• Interfering with facial mimicry impairs social perception, highlighting its role in understanding the nuances of emotional expressions.
• These findings underscore the embodied nature of social cognition, where motor processes inform perceptual judgments.