Exchanging smiles and frowns, raised eyebrows and scrunched noses, we mimic our interlocutors' facial expressions - a fundamental behavior that helps us understand each other, finds new research by a Cornell-led team of scholars in psychology and neuroscience.
Previous studies have suggested mimicry would occur between people who like each other, improving the quality of their interaction. Examining dialogue between U.S. political actors - during congressional hearings and interviews on popular cable news networks and late-night comedy shows - the new research found mimicry to be common even when known partisans disagreed.
"People mimicked each other no matter what facial expression we tested, no matter if they agreed or disagreed, or if they were Republicans or Democrats," said Inbal Ravreby, a member of the College of Arts and Sciences' 2024 cohort of Klarman Postdoctoral Fellows. "Our findings suggest that facial mimicry is fundamental to human social interactions."
Ravreby is the first author of "The Many Faces of Mimicry Depend on the Social Context," published Nov. 18 in the journal Emotion, with co-authors from Tel-Aviv University, Ben-Gurion University and The Open University of Israel.
Mimicry studies have mostly been conducted in labs, with participants passively looking at photos or short videos involving limited facial expressions. The authors wanted to investigate a real-life context involving a wider range of emotions, and probe further if emotional mimicry is a limited or more widespread practice. Based on previous findings, they expected to see it only in positive facial expressions, when people agreed, but not when they disagreed.
To test the hypothesis, the researchers turned to political interviews involving prominent U.S. political and media figures, from President-elect Donald Trump and former Fox News host Tucker Carlson to Sen. Bernie Sanders and former "Daily Show" host Trevor Noah. From hundreds of samples, they selected 150 video clips in which both interviewer and interviewee could be seen simultaneously while seeing each other, and it was clear if they agreed or disagreed. The analysis included 100 clips in which pairs agreed with each other and shared the same affiliation - 50 Republican/conservative, 50 Democrat/liberal - and 50 mixed pairs who disagreed.
Using "OpenFace" software employed widely by researchers to categorize and measure facial expressions, the team analyzed the expressions' intensity and levels of mimicry across six emotions: happiness, sadness, anger, fear, disgust and surprise. Facial movements that were sometimes obvious and intentional, sometimes subtle and subconscious, counted as mimicry if repeated within one second of the initial action.
Surprisingly, Ravreby said, mimicry was observed at levels significantly above what would occur by chance in all 18 combinations of political pairings and facial expressions. Differences in agreement were manifested only in patterns, in combinations of the degrees of mimicry in the six facial expressions. Those patterns predicted - again, above chance percentages - which pairs agreed or disagreed, and which were Republicans or Democrats.
The researchers suggest that mimicry is so common because it creates valuable feedback into our counterpart's perspective, improving our understanding of an interaction whether positive or not.
"Even if I completely disagree with someone, I likely want to understand what they are saying, to put myself in their shoes," Ravreby said. "Research has suggested we would mimic people we like more, but it seems that it's way more fundamental than that. We just tend to mimic others' facial expressions."
While politics was not the focus of the research, Ravreby said she considered the finding hopeful.
"Regardless of polarization, we are at first aligned to a degree, and that's encouraging," she said. "If we want to understand someone, we mimic them."
In addition to Ravreby, co-authors were Mayan Navon, a postdoctoral fellow at Université catholique de Louvain in Belgium; and Eliya Pinhas, Jenya Lerer, Yoav Bar-Anan and Yaara Yeshurun, all graduate students and faculty at Tel Aviv University. The research was supported by the Israel Science Foundation and the Ariane de Rothschild Women's Doctoral Program.
