Say "Cheese!"

When getting ready to take a photo, it is customary for the photographer to advise the model to say "cheese" in order to bring a genuine smile to their face. But what about that silly phrase makes one feel inclined to smile for the camera? What really goes on behind a smile?

The action of producing a smile is based on something that is very well known to most biology students--a positive feedback loop! This can take two paths either starting with a person being happy or starting with a person smiling. When a person smiles, certain muscles in their face activate and send a signal to their brain which releases endorphins and dopamine, relaxing their body and making them feel happy! So basically, when we smile, our body tells us to be happy! But what about the term "fake it until you make it?" Can faking a smile change someone's mood?

The Zygomaticus major and minor, Orbicularis oculi, Levator labii superioris, Levator anguli oris, and Risorius are required to smile.

Research shows that yes, simply slapping a smile on one's face can change their negative mood into a positive one. Putting a smile on one's face can activate this feedback loop which stimulates their reward system and releases endorphins, causing them to feel happy even if their smile was only for show. So, next time you're feeling down try putting a smile on your face, it could have a drastic affect on your mood.

An outline of the possible paths of smiling feedback loops

Not only can smiling positively affect yourself, it can affect others' moods too. Smiling can make other people feel comforted and can give off a friendly vibe from a complete stranger as well as encouraging positive interactions between any two people. As you can see, a smile can so easily change your own mood and make you feel happier. Because of this, why not smile at a stranger you walk past on the streets? This small gesture is almost guaranteed to bring a smile to their face and lift their spirits as well.

While smiling can have a positive impact on humans, does smiling have any impact on animals? Anyone with pets most likely has some miraculous story about their pet smiling at them and therefore professing their love (I mean, we all wish it was that simple). While animals do smile, it does not have quite the same connotation as a human smile. Animals tend to have two smiles: a barring teeth "smile" and an open mouth smile. Unlike humans, animals showing their teeth can often be seen as a sign of aggression, with intent to scare off all their predators by showing their scary fangs. So, in some cases a friendly smile from an animal may be more related to a sign of aggression and an active threat. On the other hand, a wide open mouth with visible gums and teeth can have the exact opposite meaning. It can be the animal's way of communicating genuine happiness and joy.

A smiling doggo

Surprisingly, these two types of smiles can be related back to humans. Think about going to an amusement park and going on the biggest and fastest rollercoaster in the park. When you actually get on the ride, your face makes a kind of smile, or a grimace out of fear or nervousness rather than pure joy. Or giving a gift to someone that you're not sure they will like, you can find yourself smiling out of nervousness towards their approval. Of course humans also smile when experiencing genuine joy and happiness as well, being the more popular of the two.

How did it come about that similar expressions have almost opposite meanings when talking about animals versus humans? Like most things, this can be traced back to evolution. The friendly expression that comes with a smile from a human most likely evolved from a baring teeth through a sign of aggression, much like animals. This idea comes from the fact that there is a "missing link" when it comes to primates' facial expressions-their expressions neither signify a friendly expression nor an aggression expression. In higher primates, flashing one's fangs was used as a sign of submission. In flashing their teeth, the primate admits fear and essentially asks for the dominant primate to go easy on them. Later on, flashing one's teeth became popular among higher primates such as chimpanzees. They would flash their teeth to their equals, or their friends and moved towards being a friendly sign rather than a fearful sign, leading to the use of the smile that we now and love today :)

At the end of a day, a smile can have a greater impact than you may think. This simple gesture has the potential to brighten your own day along with someone else's. Next time you find yourself taking a photo, don't forget to tell the subjects to say "cheese," it could have a greater effect than you may notice.