Smiling is perhaps one act that separates humanity from all other species on earth. It serves as a friendly gesture probably only in human society. People visit their local family dentist in practices like Gentle Dentist just to get their smiles fixed and be more presentable. Why is that?
Teeth-Baring From Another Perspective
Smiling is not endemic to humans if you look at it as a mere act without a meaning. Other animals bear their teeth regularly. If you put meaning to it, however, it’s where the divide shows. Humans bear their teeth as a friendly gesture, while other animals do it as a fear response. For instance, a chimpanzee baring his teeth is preparing for an attack because he feels cornered and/or threatened.
According to Vancouver Island University philosophy professor Janice Porteous, the human smile may have evolved from that aggressive display. Porteous notes that the meaning of teeth-baring isn’t uniform in primate society. In lower primates, it denotes aggressiveness. Some higher primates, on the other hand, do it as a sign of dominance. A subordinate flashes his teeth to the dominant one if he wants to take the latter’s spot, but not as an act of challenging the dominant one. Rather, the expression deflects the dominant one’s aggression and acts as a signal of submission.
Professor Frank McAndrew of Knox College agrees. Primates that bare teeth that are held together often do it as a sign of submission. A threat is shown by curled lips and teeth further apart. It’s a sign that the threatened individual is ready to bite. Relaxed lips and teeth that are pressed together obviously make for a less-threatening visage.
Smiling in Modern Human Society
But keep in mind that the non-threatening baring of teeth isn’t always an act of submission or appeasement. In a way, humans retained that. Just think of fake smiles. Still, the act of smiling in humans may have evolved from more than just submitting to authority.
Scientists also point to ‘fang flashing’, which lower primates do on a regular basis with friends. Individuals of equal stature within the society bare their teeth at each other if they see each other after a long time. They even embrace each other after the act. This is perhaps the closest representation of the birth of the human smile.
Whatever comes, however, just keep smiling at other humans just to be safe. Its meaning is still largely endemic to the human race. Try smiling at a chimp, and you might be in big trouble.