Home » News » New Research Suggests We Shouldn’t Trust Facial Expressions

New Research Suggests We Shouldn’t Trust Facial Expressions

New research has found that facial expressions might not be reliable indicators of emotion.

In fact, researchers at Ohio State University warn that it might be more accurate to say we should never trust a person’s face.

“The question we really asked is: ‘Can we truly detect emotion from facial articulations?'” said Dr. Aleix Martinez, a professor of electrical and computer engineering at The Ohio State University. “And the basic conclusion is, no, you can’t.”

For the study, researchers analyzed the kinetics of muscle movement in the human face and compared those muscle movements with a person’s emotions. What they discovered is that attempts to detect or define emotions based on a person’s facial expressions were almost always wrong.

“Everyone makes different facial expressions based on context and cultural background,” Martinez said. “And it’s important to realize that not everyone who smiles is happy. Not everyone who is happy smiles. I would even go to the extreme of saying most people who do not smile are not necessarily unhappy. And if you are happy for a whole day, you don’t go walking down the street with a smile on your face. You’re just happy.”

It is also true that people sometimes smile out of an obligation to social norms, he said.

This would not inherently be a problem, but some companies have begun developing technology to recognize facial muscle movements and assign emotion or intent to those movements, he noted.

The researchers analyzed some of those technologies and largely found them lacking, he said.

“Some claim they can detect whether someone is guilty of a crime or not, or whether a student is paying attention in class, or whether a customer is satisfied after a purchase,” he said. “What our research showed is that those claims are complete baloney. There’s no way you can determine those things. And worse, it can be dangerous.”

The danger lies in the possibility of missing the real emotion or intent in another person, and then making decisions about that person’s future or abilities, Martinez warns.

Consider a classroom and a teacher who assumes that a student is not paying attention because of the expression on the student’s face. The teacher might expect the student to smile and nod along if the student is paying attention. But maybe that student, for reasons the teacher doesn’t understand — cultural reasons, perhaps, or contextual ones — is listening intently, but not smiling at all. Martinez argues it would be wrong for the teacher to dismiss that student because of the student’s facial expressions.

After analyzing data about facial expressions and emotion, the research team, which included scientists from Northeastern University, the California Institute of Technology and the University of Wisconsin, concluded that it takes more than expressions to correctly detect emotion.

Facial color, for example, can help provide clues, researchers found.

“What we showed is that when you experience emotion, your brain releases peptides — mostly hormones — that change the blood flow and blood composition, and because the face is inundated with these peptides, it changes color,” Martinez said.

The body offers other hints, too, he said, such as posture.

Context also plays a crucial role, he said.

In one experiment, Martinez showed study participants a picture cropped to display just a man’s face. The man’s mouth is open in an apparent scream, his face bright red.

“When people looked at it, they would think, wow, this guy is super annoyed, or really mad at something, that he’s angry and shouting,” Martinez said. “But when participants saw the whole image, they saw that it was a soccer player who was celebrating a goal.”

In context, it’s clear the man is very happy. But isolate his face and he appears almost dangerous, Martinez said.

Cultural biases play a role, too.

“In the U.S., we tend to smile a lot,” he said. “We are just being friendly. But in other cultures, that means different things. In some cultures, if you walked around the supermarket smiling at everyone, you might get smacked.”

The findings show that people — from hiring managers to professors to criminal justice experts — should consider more than just a facial expression when they evaluate another person.

And while Martinez is “a big believer” in developing computer algorithms that try to understand social cues and the intent of a person, he added that two things are important to know about that technology.

“One is you are never going to get 100 percent accuracy,” he said. “And the second is that deciphering a person’s intent goes beyond their facial expression, and it’s important that people — and the computer algorithms they create — understand that.”

The study’s findings were presented at the 2020 meeting of the American Association for the Advancement of Science.

Source: Ohio State University

New Research Suggests We Shouldn’t Trust Facial Expressions

Janice Wood

Janice Wood is a long-time writer and editor who began working at a daily newspaper before graduating from college. She has worked at a variety of newspapers, magazines and websites, covering everything from aviation to finance to healthcare.

APA Reference
Wood, J. (2020). New Research Suggests We Shouldn’t Trust Facial Expressions. Psych Central. Retrieved on September 30, 2020, from
Scientifically Reviewed
Last updated: 15 Feb 2020 (Originally: 16 Feb 2020)
Last reviewed: By a member of our scientific advisory board on 15 Feb 2020
Published on Psych All rights reserved.