Flexible use of quorum and numerosity principles in evaluation of social and non-social cues in group contexts

Although gaze following is an important socio-interactive process, little is known about how this behavior is affected when multiple gaze cues are encountered in groups. Emerging research suggests that both visual consistency of cues and group size may play a role. For example, in groups of three, a minority of target-congruent gaze cues (or 1/3 faces looking at the target) have been found to facilitate target responses, whereas in groups of five, a majority of target-congruent gaze cues (or 3/5 faces looking at the target) were needed for the same effect. Here, in two preregistered experiments, we provide a high-powered conceptual replication of these past experiments and extend them to examine the possible uniqueness of responses to gaze using a comparison with arrows. We found that a minority of target-congruent gaze and arrow cues significantly facilitated target responses regardless of group size. Furthermore, we found that additional target-congruent cues, either gaze or arrows, led to further significant response facilitation. Thus, initially, responses were facilitated by a minority proportion of target-congruent cues with response times continuing to decrease with increasing numerosity of cues' spatial consistency toward the target. This suggests that humans may use both quorum-like and numerosity evaluation flexibly to guide responses in contexts presenting with multiple social or non-social cues.