Things Yoram knows: Maybe stop smiling at the world already?

"Nemari" asks: What is the reason why in dogs and other animals the baring of the teeth shows aggression, and in humans the same gesture has become a friendly signal?

Indeed, in dogs baring teeth accompanied by a growl is a threat, but our smile does not correspond to the warning of our best friend. Our smile is mute and does not necessarily include exposing teeth. And to the eye, the first smile of every person, at about the age of a month, reveals empty gums.

Our ape relatives have a gesture reminiscent of a human smile - silent baring of teeth when the monkey stands in place in a defensive and evasive position. In macaque monkeys or baboons, this expression is always directed by a junior monkey to his senior and it expresses submission. In the chimpanzees who have developed more sophisticated communication, this raw "smile" has received additional functions and is used in addition to calming the alpha male, also for reconciliation, reconciliation and expression of closeness between chimpanzees of equal status.

But what does the smile do for us humans who are able to put into words what they want to transmit to the world? Strangely, the smile not only did not become extinct, but took on, in human society, a greater meaning than it had with our ancestors.

In humans, two types of smile can be distinguished. The first type is the "stewardess smile" that we wear on our faces when we stand, for example, in front of a camera. The decision for such a smile is made in the cerebral cortex in the left hemisphere. From there the message goes to the zygomaticus muscle in the cheeks to raise the lips. Since the left half of the brain is connected to the right half of the body, the fake smile will be asymmetrical: the right side of the mouth will be higher than the left. This smile activates only the lips while the muscles surrounding the eye are not involved and it appears and disappears as quickly as we decide on it. The second smile, the spontaneous one, is an involuntary expression of a mental state and for it Mother Nature built us a special neural pathway deep under the cerebral cortex responsible for conscious thinking. This smile is symmetrical, it also contracts the muscle surrounding the eye (Orbicularis oculi) to create characteristic wrinkles and it appears and disappears slowly. The face is the "notice board" of the body, so it is reasonable that the smile is a means of communication, but what is the advantage of a sign that will betray an emotional state in a way that is difficult to imitate? Several explanations have been proposed to solve the puzzle of the smile: a hypothesis is requested that it is seen as a sexual advertisement: a smiling face is more attractive and natural selection has cultivated an expression that will attract the boys (girls) of the opposite sex. Alternatively, it can also be assumed that the human smile did not stray so far from its father - the monkey's submissive smile and it is a sign of reconciliation towards higher ranks. The anthropologist Robin Dunbar made observations of groups of people meeting in public places, counted the natural and artificial smiles and examined who was smiling at whom. It turns out, contrary to the sexual advertising hypothesis, that most of the smiles are directed towards members of the same sex and contrary to what would be expected if the smile was a submissive gesture, most of the smiles, especially the spontaneous smiles, were directed towards an equal. So what is the role of the smile anyway?

The answer probably lies precisely in the fact that it is not easy to smile. Not easy, almost acrobatic is the attempt to put on the face an imitation of a real smile. Just as the peacock's tail, precisely because it is heavy and prominent, indicates physical health, so the difficulty of faking makes the smile a reliable sign of willingness to cooperate. Man is a social animal and his survival depends not least on the ability to form partnerships with others. The benefit of cooperation is very great but with it increases the danger of fraudsters who will take advantage of the willingness of the other members of the group to behave altruistically. Natural selection will simultaneously encourage the building of mutual trust relationships and at the same time fraud detection mechanisms. The researcher Ryo Oda asked students to answer a questionnaire regarding their level of altruism through questions such as "do you take on group tasks on your own initiative", do you help your friends with their homework, do you feel like helping a person who stumbles in a public place, etc. The subjects were photographed for a short video and foreign subjects were asked to assess, based on expressions alone, the social nature of the person being photographed. It turns out that the symmetrical smile, the crinkling of the eyes appears more in those who are committed to the group and its members and that humans know how to recognize such non-verbal signs.

An experiment to quantitatively test our trust in other people uses a business game. A group of subjects who were strangers to each other was divided into two, half of the subjects received a sum of money each and were given the opportunity to transfer part of the money to a random partner chosen for them from the other group. The money they transfer, according to the rules of the game, will be tripled and the recipient will decide how much of the profit to return to them.

Game theory (the branch of mathematics that deals with decision-making) predicts that the recipient of the money has no reason to return even one penny to the anonymous partner and the participant who received money from him should not transfer anything to him.

It turns out that we put a little more trust in strangers than computer software predictions: the person who receives $10 for a game trusts his partner enough to transfer close to $6 on average, and the recipient is reliable enough to return $7 on average. But - the averages reflect a wide distribution. There are those who transfer all the money to an unknown person in front of them and some who took home the amount without taking any risk; Among the recipients are those who pocket the entire profit and those who share it with those who trusted them.

In an experiment in which the participants addressed each other through a short video clip, it became clear that the one who smiled genuinely was also a better partner - trusted the partner and justified the trust. It was also found that the researched knew who was worthy of partnership based on their facial expressions, an artificial "stewardess smile" did not help to increase trust and those who intended to conduct an egoistic strategy simply failed to create a convincing smile. The meaning of this is that the smile is really a reliable and difficult to fake sign of good intentions and that it is worth investing information processing resources to decipher the subtle clues that the facial muscles send us. In another experiment it turned out that players are willing to pay to see their partner's face and it is possible that this willingness is absolutely rational.

If the smile is a means of communication that means trust and belonging, what is the meaning of smiling for the camera and why are those who greet us in a business instructed to put on an artificial smile? Well the flight attendant smile is a relatively new invention. People who immortalized their faces in portrait paintings in the previous centuries almost never smiled when painting, and when portrait painting was replaced by photography in the second half of the 19th century, the photographers asked the photographed to make a serious facial expression. that shrinks the mouth. A closed mouth is considered more respectable and considering the state of the teeth of the majority of the population in those years it would have been better for the photograph to reveal as few of them as possible, also the long exposure time required made it difficult for the photographed to persist in smiling throughout the process.

The Kodak company, which was, from the end of the 19th century and for most of the 20th century, a monopoly in the field of photography, changed the situation. In an aggressive advertising campaign spanning years, Kodak turned photography into a consumer experience and the photographs it distributed were no longer portrait-like but conformed to the happy consumer model. The company did not hesitate to sacrifice a branch of photography that was acceptable and profitable in the 19th century: photographs of deceased persons after death in order not to harm the new and cheerful image of the family camera. Thus, after decades of smiling Kodak photographers, World War II was the first war in which conscripts smiled for the camera in the souvenir photo they left behind. The smile of the flight attendant and the waiter came into existence following the Kodak smile when it is aimed at consumers who have been accustomed since childhood to fill albums with faces baring their teeth.

In other words, the saying "smile and the world will smile at you" is as stupid as it sounds. Never really cares what you do with your lips and if you smile at him he'll think you're trying to sell him a club card. Try to help your friends and be worthy of their trust and then the smile will come naturally.
Thanks to Dr. Robin Dunbar and Dr. Ryo Oda for their help
Did an interesting, intriguing, strange, delusional or funny question occur to you? Send to ysorek@gmail.com

More of the topic in Hayadan:

• The secret of a smile
• With a warm smile or a cold emotion?
• rolling with laughter