Most previous work on emotions has been conducted using static facial images. In this work, I examine the effects of dynamic properties of smiles in combination with head-tilt and gender on person and expression perception. With the use of graphics animation software, two different smile dynamics (short, long onset-duration) were synthesised in male and female computerised characters with either no, left or right head-tilt. Results showed that stimulus persons displaying an authentic smile, i.e. a smile with a long onset-duration, were perceived as more trustworthy, more attractive and less dominant. These smiles were also rated as more authentic and flirtatious. The influence of smile dynamics and head-tilt on person perception further varied as a function of both the gender of the stimulus person and the perceiver. The findings of this research provide novel insights into the interrelation of nonverbal cues in person perception, and have implications for fields such as psychology, marketing, and computer science.

Eva G. Krumhuber, PhD. Undergraduate and postgraduate training in psychology at the Universities of Salzburg (Austria), Würzburg (Germany), Cambridge and Hull (UK). Doctoral research in social psychology at Cardiff University, UK. Since 2013 assistant professor in social cognition at University College London, UK.