Do facial expressions transcend culture?

Humans are emotional beings, with feelings that show in our behaviours and facial expressions. But whether these mean the same thing in different cultures has been hotly debated.

In what researchers say is the first worldwide analysis in naturalistic settings, a new study published in the journal Nature has found that different social contexts, such as weddings, funerals, humour, art and sports, do indeed elicit universal facial expressions.

“We found that rich nuances in facial behaviour – including subtle expressions we associate with ‘awe’, ‘interest’, ‘triumph’ – are used in similar social situations around the world,” says lead author Alan Cowen from the University of California Berkeley, US.

Expressions perceived as awe were associated with fireworks, toys and dance, for instance, while triumph was associated with sporting events, police with doubt, and concentration with study and martial arts. They are “a lot richer and more complex than many scientists have assumed based on survey data”, says Cohen.

Maybe Charles Darwin was right in arguing that “human facial expression is a universal language of social life”, as the authors note. But survey data have been constrained by language barriers and small samples, adding to conflicting evidence and perspectives.

Cowen’s team used a machine learning model, deep neural network (DNN), to systematically analyse facial expressions in thousands of different contexts from more than six million videos uploaded to YouTube between July 2009 and May 2018 by people in 144 countries.

Facial expressions were rated by English speakers in India by selecting applicable emotions from a list of 31 labels – which they were familiarised with beforehand – resulting in a total of 16 distinct facial expressions. Contexts were classified in a separate experiment.

Analysis showed a 70% overlap overall in links between facial expression and context, which the authors say is “evidence for substantial universality in our cyber-connected world”.

Results also suggest expressions could have several meanings in different contexts: pain expressions, for instance, were seen in obvious contexts such as weightlifting but also appeared in relation to music, which the authors say aligns with other work reporting sentimental expressions of musicians.

The paper is “sure to be a subject of lively debate”, writes Lisa Barrett, from the Northeastern University College of Science, US, in a commentary in the journal, in which she applauds the study’s clear strengths, but also scrutinises the details.

She notes, for example, that the “raters” were given the emotional word ratings rather than labelling the expressions themselves. They used emotion labels such as ‘anger’, ‘fear’ and ‘sadness’ instead of descriptive terms such as ‘scowl’, ‘wide-eyed gasp’ and ‘frown’, thereby inferring the emotion behind the expressions.

She further comments that the raters saw the faces in context, which can’t necessarily be separated from the emotions themselves, and, “perhaps most central to the question of universality”, they were from just one country.

“The ultimate value of Cowen and colleagues’ study might lie not in the answers it provides,” she concludes, “but in the opportunity for discovery that it opens up.”

For his part, Cowen says the study doesn’t give the final say on whether facial expressions are biologically innate or culturally learned. “As a caveat, all of the cultures we studied had internet access, so it’s possible our findings reflect the spread of facial expressions through globalisation.”

Interestingly, he notes they didn’t see any evidence of Western European facial expressions dominating the spread, even though you’d expect them to be more highly represented online.

Rather, they found that links between expressions and context in Indonesia and the Philippines were closest to the world average. And neighbouring regions such as the Middle East and India shared 85% of their variance with each other but only 64% with the US and 54% with Canada.

“We do see some evidence for more dispersed geographic diffusion of facial expressions, and it seems to suggest that they’re a little bit cultural,” says Cowen. “But overall, a strong case is emerging that some facial expressions are biologically prepared.”

This is supported by other evidence the group unearthed linking context-related expressions in ancient Mayan sculptures with Western intuitions about emotion, that predate cultural contact with Western Europe.