How Facial Expressions Relate to Emotions and Thoughts

Over the past century or so, scientists have been wondering how it is that our emotions and thoughts can modify our expressions. This may seem natural, and indeed it is, but the mechanism behind this ability, or drawback as some call it, is still a mystery. A new investigation has recently determined that changing facial expressions, such as frowning, hinder people's abilities to understand written language related to emotions. The findings were presented on Friday, January 29, at the Society for Personal and Social Psychology meeting, in Las Vegas. The work is also scheduled for publication in an upcoming issue of the respected scientific journal Psychological Science.

About 40 participants were involved in the new experiments. Scientists used the powerful nerve toxin botulinum, commonly referred to as Botox, in small amounts, to paralyze a select series of nerves on the test subjects' faces. All these nerves were related to expressing frowning. David Havas, the first author of the new investigation, and also a PhD candidate in psychology at the University of Wisconsin-Madison (UWM), says that the research was conducted so that he and his team could gain a deeper understanding of the interactions that appeared between facial expressions, thoughts and emotions.

“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,” Havas explains. The participants in the study were asked to read angry, sad and happy sentences before and two weeks after the Botox injections. Upon finishing and understanding the test sentences, they had to push a button, to let researchers know that they were done.

After the Botox injection, when their ability to frown was impeded, the test subjects showed the same response time in reading the happy sentence, but took a lot more time to understand the sad and angry ones. “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,” Arthur Glenberg, a UWM professor emeritus of psychology, and Havas' PhD advisor, says.

“Language has traditionally been seen as a very high level, abstract process that is divorced from more primitive processes like action, perception and emotion. This study shows that far from being divorced from emotion, language understanding can be hindered when those peripheral bodily mechanisms are interrupted,” the PhD student concludes.