Facial Expressions are a Gateway to Let Others Know How You Feel
According to study's first author, David Havas, a Ph.D. candidate from University of Wisconsin-Madison psychology, the interactions of facial expression, thoughts and emotions has always intrigued researchers.
During the study, researchers recruited 40 people who were treated with botulinum toxin, or Botox.
Tiny applications of this powerful nerve poison were used to deactivate muscles in the forehead that cause frowning.
They analysed people after a pinpoint treatment to paralyze a single pair of "corrugator" muscles, which cause brow-wrinkling frowns.
To test how blocking a frown might affect comprehension of language related to emotions, Havas asked the patients to read written statements, before and then two weeks after the Botox treatment.
Havas gauged the ability to understand these sentences according to how quickly the subject pressed a button to indicate they had finished reading it.
The study showed no change in the time needed to understand the happy sentences. But after Botox treatment, the subjects took more time to read the angry and sad sentences. Although the time difference was small, it was significant, he adds.
"There is a long-standing idea in psychology, called the facial feedback hypothesis," said Havas.
"Essentially, it says, when you're smiling, the whole world smiles with you. It's an old song, but it's right. Actually, this study suggests the opposite: When you're not frowning, the world seems less angry and less sad," he added.
UW-Madison professor emeritus of psychology Arthur Glenberg said that the study has broken new ground by linking the expression of emotion to the ability to understand language.
"Normally, the brain would be sending signals to the periphery to frown, and the extent of the frown would be sent back to the brain. But here, that loop is disrupted, and the intensity of the emotion, and of our ability to understand it when embodied in language, is disrupted," he added.
The study appears in the journal Psychological Science.