Beyond shared signals: The role of downward gaze in the stereotypical representation of sad facial expressions.

According to the influential shared signal hypothesis, perceived gaze direction influences the recognition of emotion from the face, for example, gaze averted sideways facilitates the recognition of sad expressions because both gaze and expression signal avoidance. Importantly, this approach assumes that gaze direction is an independent cue that influences emotion recognition. But could gaze direction also impact emotion recognition because it is part of the stereotypical representation of the expression itself? In Experiment 1, we measured gaze aversion in participants engaged in a facial expression posing task. In Experiment 2, we examined the use of gaze aversion when constructing facial expressions on a computerized avatar. Results from both experiments demonstrated that downward gaze plays a central role in the representation of sad expressions. In Experiment 3, we manipulated gaze direction in perceived facial expressions and found that sadness was the only expression yielding a recognition advantage for downward, but not sideways gaze. Finally, in Experiment 4 we independently manipulated gaze aversion and eyelid closure, thereby demonstrating that downward gaze enhances sadness recognition irrespective of eyelid position. Together, these findings indicate that (1) gaze and expression are not independent cues and (2) the specific type of averted gaze is critical. In consequence, several premises of the shared signal hypothesis may need revision.