It is written in the eyes: Inferences from pupil size and gaze orientation shape interpersonal liking

Research has shown that pupil size shapes interpersonal impressions: Individuals with dilated pupils tend to be perceived more positively than those with constricted pupils. Untested so far is the role of cognitive processes in shaping the effects of pupil size. Two pre-registered studies investigated whether the effect of pupil size is qualified by partner’s attention allocation inferred from gaze orientation. In Experiment 1 (N=50) partners with dilated pupils were more liked when gazing toward the participant, but less liked when gazing toward a disliked other. Experiment 2 (N=50) unveiled the underlying mechanism of the pupil-gaze interplay. Pupillary changes led to inferences about the feelings held by the partner towards the gazed target: larger the pupils signaled positive feelings. Crucially, target identity moderated the response of the participants (i.e., liking toward the partner). This work shows the importance of considering the interplay of affective and cognitive eye-signals when studying person perception.