Psychology research is not generally very good at capturing change. Measurements tend to be fairly static, either looking at one slice of time or asking participants to average over a period. Which is why this research on smiling is so unusual. Some of the best known research on smiling is about how people judge an authentic smile – the so-called ‘Duchenne smile’ or the ‘crinkly-eyed smile’. What this research asks, though, is how does a smile’s speed in combination with head-tilt and gender affect its perception.
In this experiment, one hundred participants, half men half women, were sat in front of a monitor to judge the smiles of synthetic faces (Krumhuber, Manstead & Kappas, 2007). They watched the faces smiling – some whose smile appeared in just over 0.1 of a second, and some whose smile appeared in just over 0.5 of a second. At the same time, some of the heads were tilted to the left and some to the right. Participants then had to judge the smiles on how trustworthy, attractive, dominant, fake and flirtatious they made the faces seem.
The study replicated a previous finding that a long-onset smile (0.5s onset) is seen as more authentic and flirtatious. On top of this, the researchers found long-onset smiles were perceived as more attractive, more trustworthy and less dominant. Head tilting also increased attractiveness and trustworthiness but only if the head was tilted in the right direction. In this case, the right direction was the same way as eye orientation or towards a partner.
There was also evidence that smiles are perceived in different ways depending on the gender of both the target and the observer. Previous research has found that smiling is associated with attractiveness in women, but dominance in men. These are probably a result of gender stereotypes. One finding in the present study was that women’s smiles were judged less authentic than men’s. Krumhuber et al. (2007) speculate that this is because women tend to smile more than men, so their behaviour is seen as more usual and therefore less informative. The reverse may be true for men.
While women’s smile were more likely to be discounted, it seemed women were generally better at detecting the difference between short- and long-onset smiles. The differences found in this study, therefore, were mostly due to female participants rather than the men. Krumhuber et al. (2007) suggest this ties in with findings men are more likely to interpret ambiguous or inauthentic signals (short-onset smiles) as flirtatious behaviour. They can’t (or won’t) tell the difference.
» This post is part of a series on nonverbal behaviour.