Moving Smiles: The Role of Dynamic Components for the Perception of the Genuineness of Smiles

Three experiments were conducted to examine whether the temporal dynamics of Duchenne-smiles influenced the perception of smile authenticity. Realistic computer-generated Duchenne-smiles that varied in their onset- and offset-durations (Experiment 1), or only in their offset-duration (Experiment 2), or in both their onset- and apex-durations (Experiment 3), were created using Poser 4 software. Perceived genuineness varied monotonically with the duration of each manipulated dynamic component. The results are in accordance with Ekman and Friesens (1982) observations regarding the duration of smiles of enjoyment, which suggest that each dynamic component has a distinct duration range that can influence the perceived genuineness of smiles.We wish to thank Jesse Spencer-Smith for sharing the AU morph targets that have been developed in the context of his research.     

Temporal Aspects of Facial Displays in Person and Expression Perception: The Effects of Smile Dynamics,Head-tilt,and Gender

Recent work suggests that temporal aspects of facial displays influence the perception of the perceived authenticity of a smile. In the present research, the impact of temporal aspects of smiles on person and expression perception was explored in combination with head-tilt and gender. One hundred participants were shown different types of smiles (slow versus fast onset) in combination with three forms of head-tilt (none, left, or right) exhibited by six computer-generated male and female encoders. The encoders were rated for perceived attractiveness, trustworthiness, dominance, and the smiles were rated for flirtatiousness and authenticity. Slow onset smiles led to more positive evaluations of the encoder and the smiles. Judgments were also significantly influenced by head-tilt and participant and encoder gender, demonstrating the combined effect of all three variables on expression and person perception.