People with little animation in facial expression or who suffer from facial paralysis are perceived as being less happy simply because they can't communicate in the universal language of facial expression, according to a recent study.

The recent findings from Oregon State University highlight the important role the face plays in everyday communication and indicates people may hold a prejudice against those with facial paralysis because of their disability.

"People are more wary and more likely to form a negative impression of someone with a disability," Kathleen Bogart, an assistant professor of psychology in the College of Liberal Arts at Oregon State University, said in a statement. "Identifying that stigma is the first step to addressing it."

Facial paralysis is highly visible.

"Everyone notices there's a difference, but people have no idea why," Bogart said. "They don't understand the nature of the condition."

Bogart and her colleagues recruited nearly 120 people for the study. The participants, none of whom had facial paralysis, watched or listened to videos of people with varying degrees of facial paralysis and were asked to rate the subject's emotions as the person recounted happy or sad experiences.

Those with severe facial paralysis were rated as less happy than those with milder facial paralysis across all the different communication types and combinations. Those with severe facial paralysis were also rated as less sad than those with milder facial paralysis.

The findings confirmed that people with facial paralysis experience stigma, but it also confirmed that people often rely on a combination of communication channels to perceive emotions.

That's important because people with facial paralysis can adapt other communication channels, such as tone of voice or gestures, to enhance their communication ability, she said. Also, people interacting with someone with facial paralysis can be more watchful of other communication cues that might indicate emotion, she said.

"It's not all about the face," Bogart said. "Studies like this tell us more about the way people communicate, verbally and non-verbally."

The findings were published in the in the journal Basic and Applied Social Psychology.