Not so rapid: Dominant-looking faces elicit deliberate but not efficient search

To navigate the dominance hierarchy, humans evaluate trait dominance from facial appearance spontaneously. Though unwarranted, these evaluations predict important social outcomes. The present study, however, focused on the cognitive impact of facial dominance. We investigated whether and how facial dominance shapes attentional selection and target identification. Imagine that you are searching for Hulk (a Marvel character) in the crowd, could you rapidly detect and identify him? We adopted the visual search paradigm to mimic these everyday tasks and to link facial dominance with attention and decision-making. From the traditional ethology perspective, a threat detection system is assumed existed to reflexively detect dominant faces, which helps avoid costly physical confrontations. Here, we provided counterintuitive demonstrations showing that searching for dominant-looking faces slowed, rather than accelerated the search process. Participants viewed arrays of faces and located a face with specified identity, rendering the dominance dimension itself task-irrelevant. In Experiment 1, we also manipulated the congruency between targets and distractors on their dominance (i.e., high dominance versus low dominance). The search was more efficient when the target face differed from distractors by dominance. That is, participants implicitly detected the dominance distinction and leveraged it to guide searches. Critically, the search for the high-dominant faces (versus low-dominant faces) was more time-consuming. Next, in Experiment 2 we included eye-tracking to reveal search processes and showed that search inefficiency for high-dominant faces arose from fixating more distractors overall, spending more time interrogating each distractor, and taking longer to recognize high-dominant targets. In Experiment 3, search arrays were substituted with inverted faces. Although inversion disrupts explicit dominance inferences, those inverted dominant faces were detected inefficiently likewise, hinting at the perceptual underpinning of dominance evaluation. These findings suggest that humans display cautious and deliberate strategies to look for dominant individuals, at the expense of search efficiency.