Emotion expression modulates perception of animacy from faces

- Participants rated whether faces appeared animate at points along a morph continuum.
- Animacy perception was influenced by both stimulus and individual variability.
- Male faces were judged to appear more animate than female faces.
- Happy faces were perceived as more animate than neutral faces.
- An externally-oriented thinking style was associated with lower animacy thresholds.

Discriminating real human faces from artificial can be achieved quickly and accurately by face-processing networks, but less is known about what stimulus qualities or interindividual differences in the perceiver might influence whether a face is perceived as being alive. In the present studies, morphed stimuli differing in levels of animacy were created. Participants made judgements about whether the face appeared animate at different levels along the morph continuum. The faces varied in terms of emotional expression (happy vs. neutral) and gender. Male faces were judged to be animate at a lower threshold (i.e., closer to the inanimate end of the continuum) than female faces. Animacy was also perceived more readily in faces with happy expressions than neutral. These effects were observed across two separate studies involving different participants and different sets of stimuli (animate faces morphed with dolls or those morphed with computer generated faces). Finally, the influence of interindividual variability in personality traits on animacy perception was examined. This revealed that an externally oriented cognitive style, a component of alexithymia, was associated with lower thresholds for perceiving animacy, for animate faces morphed with dolls. The findings are discussed in relation to inter- and intra-individual variability in animacy perception and social interaction.