EXPRESS: Induced anxiety influences the perception of negative facial expressions in single faces and face ensembles

Observers' emotional states may bias the perception of single emotional faces; however, little is known about the similar biases in the perception of face ensembles. In the present study, we explored how observers' state anxiety influences the perceived average expression intensity of the ensembles of fearful and angry faces. Participants performed the estimation task in the neutral or anxious state, and the face ensembles varied in mean facial expression intensity. We obtained the emotion-congruence-amplification effect - overestimation of a perceived average intensity in processing emotional face ensembles in an anxious state. This effect was stronger for the ensembles with lower mean intensity and for fearful compared to angry faces. The explanation of the emotion-congruence-amplification effect may be based on an attention mechanism, which focuses cognitive resources on the most salient or emotionally intense elements in an ensemble, thereby amplifying their impact. These findings deepen our understanding of how individuals' emotional states may bias social perception of emotions in group contexts.