Smiling and laughing are universally considered to be signals that show a person is happy. We cry at birth, begin smiling at five weeks and laughing starts between the fourth and fifth months. Babies quickly learn that crying gets our attention – and that smiling keeps us there. Recent research with our closest primate cousins, the chimpanzees, has shown that smiling serves an even deeper, more primitive purpose.
To show they’re aggressive, apes bare their lower fangs, warning that they can bite. Humans do exactly the same thing when they become aggressive by dropping or thrusting forward the lower lip because its main function is as a sheath to conceal the lower teeth. Chimpanzees have two types of smiles: one is an appeasement face, where one chimp shows submission to a dominant other. In this chimp smile – known as a ‘fear face’ – the lower jaw opens to expose the teeth and the corners of the mouth are pulled back and down, and this resembles the human smile.
The other is a ‘play face’ where the teeth are exposed, the corners of the mouth and the eyes are drawn upwards and vocal sounds are made, similar to that of human laughing. In both cases, these smiles are used as submission gestures. The first communicates ‘I am not a threat because, as you can see, I’m fearful of you’ and the other says ‘I am not a threat because, as you can see, I’m just like a playful child’. This is the same face pulled by a chimpanzee that is anxious or fearful that it may be attacked or injured by others. The zygomatics pull the corners of the mouth back horizontally or downwards and the orbicularis eye muscles don’t move. And it’s the same nervous smile used by a person who steps onto a busy road and almost gets killed by a bus. Because it’s a fear reaction, they smile and say, ‘Gee…I almost got killed!’
In humans, smiling serves much the same purpose as with other primates. It tells another person you are non-threatening and asks them to accept you on a personal level. Lack of smiling explains why many dominant individuals, such as Vladimir Putin, James Cagney, Clint Eastwood, Margaret Thatcher and Charles Bronson, always seem to look grumpy or aggressive and are rarely seen smiling – they simply don’t want to appear in any way submissive.
And research in courtrooms shows that an apology offered with a smile incurs a lesser penalty than an apology without one. So Grandma was right.
Source: “Smiling is a Submission Signal,” from The Definite Book of Body Language, by Allan and Barbara Pease
Photo by Beyond.The.Box