Smile

Direction matters as much as width

A smile combines several dimensions: the direction of the corners of the mouth, their movement and the quantity of teeth visible. A 2017 study using animations rated by 802 people shows that these parameters interact. In this model, stretching the mouth further did not systematically improve the result: several combinations could produce a successful expression.

Visible teeth should go with the expression

In the same experiment, showing more teeth could improve or worsen ratings depending on the rest of the movement. This warrants comparing variations on your own face rather than aiming for maximum aperture. This work on animations provides ideas for presentation; it does not define a universal number of teeth to show.

The eyes contribute to the warmth of the smile

A meta-analysis reports that Duchenne smiles are overall perceived more positively than those without eye region involvement. This concerns in particular the authenticity and attractiveness attributed by observers. However, research does not automatically equate this movement with a sincere emotion: a calm smile can also mobilize this region.

The effect also depends on the situation

The smile can enhance a face by giving a more welcoming expression, but its aesthetic effect depends on the context. A study on male attractiveness, for example, found different results depending on the type of relationship envisaged. For this sheet, the goal is to give you several usable expressions, rather than asking you to smile all the time.