The dampened smile is an attempt to control an automatic, happy one and exists because some muscles, such as the ones controlling the mouth, are easier to suppress than others. “The cheeks will be raised but we pull the corners of the mouth downwards or press the lips together."Not all cultures invite a broad smile.  In Japan, where etiquette dictates that emotions are stifled in public, there’s a greater emphasis on smiling with the eyes.

The dampened smile

Translating roughly as ‘malicious joy’, schadenfreude is the thrill of discovering another’s misfortune.“If individuals are alone and feel unobserved, they usually express feelings of schadenfreude by so-called ‘Duchenne smiles’ and ‘Duchenne laughs’,” says Jennifer Hofmann, a psychologist at the University of Zurich.

Angry-enjoyment smile

The ‘miserable smile’ is a stoical grin-and-bear-it expression – a slight, asymmetric smile with an expression of deep sadness pasted over the top.Since Landis’ classic study, psychologists have found this tell-tale smirk on the faces those watching gory films – they were filmed by a hidden camera – and among patients suffering from depression. It's a socially acceptable way of showing that you’re sad or in pain.

Miserable smile

The ‘qualifier smile’ aims to take the edge off bad news. It begins abruptly, raising the lower lip slightly, and is occasionally accompanied by a slightly downwards and sideways tilt of the head.

Qualifier smile

The ‘contempt smile’ indicates a mixture of disgust and resentment and is disconcertingly similar to a smile of true delight, except for the corners of the lips which appear tightened.

Contempt smile

Those who smile often are thought of as more likeable, competent, approachable, friendly and attractive.
Of 19 different types of smile, only six occur when we’re having a good time. The rest happen when we’re in pain, embarrassed, uncomfortable, horrified or even miserable. A smile may mean contempt, anger or incredulity, that we’re lying or that we’ve lost.

Smile ≠  happy

Most people – around 71% - can voluntarily contract the inner portion of the orbicularis oculi. Judged by facial expressions alone, people are <a href="http://psycnet.apa.org/psycinfo/1974-25177-001">j</a>udged as most truthful when they are lying. As the American humourist Kin Hubbard once said: “If you haven’t seen your wife smile at a traffic cop, you haven’t seen her smile her prettiest.”

Fake smile

“When bonobo chimpanzees are afraid they’ll expose their teeth and draw their lips back so that their gums are exposed,” says Zanna Clay, a primatologist at the University of Birmingham.In babies, a broad grin can either mean they’re happy or distressed and studies have shown that men tend to smile more around those considered to be higher status.

Fear smile

Duchenne was interested in the mechanics of facial expressions, including how the muscles of the face contract to produce a smile.The Duchenne‘ smile is long and intense, though it involves the contraction of just two muscles. First the zygomatic major, which resides in the cheek, tugs at the corners of the mouth, then the orbicularis oculi, which surrounds the eye, pulls up the cheeks, leading to the characteristic ‘twinkling eyes’.

Duchenne smile

The ‘embarrassed smile’ is identical to the dampened smile, though the two are easily distinguished – if not by the flushed cheeks, then the uncomfortable situation which usually precedes it. Another tell-tale sign is moving the head downwards and slightly to the left.

Embarrassed smile

As they hovered over their victims, knives at the ready, Carney Landis issued his instructions. The beheading was ready to commence. It was 1924 and this particularly sadistic grad student had lured an assortment of fellow pupils, teachers and psychology patients - including a 13-year-old boy - into a room at the University of Minnesota.