Blocking frowning can hamper a person's ability to read emotional sentences, a study has revealed.
While the world can tell what you are thinking or feeling just by looking at your facial expressions, but blocking them can affect your ability to understand written language related to emotions, revealed the study.
The research reported on 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.
The interactions of facial expression, thoughts, and emotions have intrigued scientists for more than a century, says the study's first author, University of Wisconsin-Madison psychology Ph.D. candidate David Havas.
Scientists have found that blocking the ability to move the body causes changes in cognition and emotion, but there were always questions.
On the other hand, Havas was studying 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.
The results 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 added.
Moreover, the changes in reading time couldn't be attributed to changes in participants' mood.
The use of Botox to test how making facial expressions affect emotional centres in the brain was pioneered by Andreas Hennenlotter of the Max Planck Institute in Leipzig, Germany.
"There is a long-standing idea in psychology called the facial feedback hypothesis. 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," said Havas.
Practically, the study "may have profound implications for the cosmetic-surgery," said co-author Arthur Glenberg.
"Even though it's a small effect, in conversation, people respond to fast, subtle cues about each other's understanding, intention and empathy. If you are slightly slower reacting as I tell you about something made me really angry, that could signal to me that you did not pick up my message," he added.
The study is published in the July issue of Psychological Science, a journal of the Association for Psychological Science.