As confirmed by various experiments, the mere fact of activating the muscles that make us smile on our faces lifts our spirits, even slightly.
Dae-su, a character from the Korean film "Oldboy", repeats these verses by the poet Ella Wheeler Wilcox (1850-1919) while forcing a smile.
At the same time, he tries to understand why they keep him kidnapped for fifteen years in a room with no other company than a television and a painting with those verses, to later release him with a mobile phone and a wallet with money. If he wants to know more about this mysterious character he will have to watch the movie. He won't regret it.
Are we sad because we cry or do we cry because we are sad? Can a smile, even a fake one, lift our spirits? Charles Darwin, in his book The Expression of Emotions in Man and Animals (1872), already described the amplifying effect of the physical manifestations of emotions (physiological changes, facial expressions...) on our affective experiences.
Based on these ideas, the American philosopher William James and the Danish physician Carl Georg Lange proposed more than a century ago that these experiences would be determined by the perception of bodily signals generated by the activity of the peripheral nervous system, such as heart rate or heart rate. Breathing frequency.
The feedback hypothesis
Since then, it has been a subject much studied by science. One of the most prolific lines of research is the one that explores the feedback hypothesis or facial feedback. This approach maintains that the activation of the facial muscles involved in the expression of certain emotions directly influences the way in which we experience them.
Thus, frowning would make us feel angry, while raising the corners of the lips would increase our sense of well-being.
Most of the studies that have tested this conjecture have been based on the simulation of facial expressions associated with emotions such as joy or anger. When the participants were then asked about their state of mind, the majority stated that they were feeling the emotion in a more intense way than in situations in which these muscles were not activated.
However, this procedure has been criticized for the fact that people could be aware of generating a smile or putting on an angry face.
With the pencil in the mouth
To circumvent the problem, Fritz Strack and colleagues (1998) developed the pencil-in-the-mouth procedure. These researchers informed a series of people that they were going to participate in a study on motor coordination in which they had to hold a pencil between their teeth (as when we force a smile) or between their lips (which prevents them from simulating it) while watching strips funny.
The results showed that the participants who were forced to smile said they had more fun than those who were prevented from smiling.
Experimento del 'lápiz en la boca'. Fuente: 'A multi-lab test of the facial feedback hypothesis by the Many Smiles Collaboration'. Nature Human Behavior (2022). CC BY
Based on these types of findings, therapeutic strategies have been developed such as those that invite you to smile for a few seconds every day in front of a mirror to increase the feeling of well-being. It has even been proposed that the injection of botulimic toxin between the eyebrows reduces the symptoms of depression.
However, other works have been unable to conclusively support the feedback hypothesis. For example, several studies have shown that the mere fact of feeling observed through a camera can make this effect disappear. It seems that the presence of such a device would reduce confidence in the inferences we make from the movements of our own muscles.
an illuminating study
In view of the contradictory findings, a recent study involving more than 3,500 people from 19 countries (including Spain and Venezuela) has tried to provide more conclusive data.
In one of the experiments, the participants had to reproduce the typical gesture of joy shown by the photograph of an actor. In another, people were instructed to voluntarily move some of the muscles involved in smiling, leading to less archetypal expressions of happiness. When the participants were later asked about their mood, they reported feeling happier, showing a similar increase on both tasks.
Furthermore, the effects were found to be independent of whether people were aware that they were imitating a smile or being watched through a camera. However, it is important to highlight that the increase in the feeling of happiness was small, similar to that caused by seeing photos of puppies or babies.
Finally, a group of participants underwent the pencil-in-the-mouth procedure. In this case, the increase in the subjective feeling of happiness was minimal.
In short, the results of this work do not provide definitive support for the facial feedback hypothesis, but they do provide important confirmation that certain movements of the muscles involved in smiling, such as the zygomatic muscle, or the imitation of facial expressions of joy promote a state of well-being.
We can conclude that smiling is enough to elevate our mood, although it is not something to get excited about. So you know, if you want to feel a little happier, raise the corners of your lips or move your cheeks, but you don't have to bite down on a pencil.
This article has been published in The Conversation.