Blinking mimicry predicts preference

Face-to-face conversations involve a rich array of social signals - facial expressions, gestures, vocal prosody, and gaze. While interpersonal mimicry of these signals has been extensively studied and shown to carry evaluative significance, one highly visible and frequent behavior remains relatively underexplored in the mimicry literature: eye blinks. Spontaneous eye blinks are shaped by cognitive and attentional states, with increased blinking associated with disengagement. Whether blink mimicry-the directional following of one person's blinks by another-carries evaluative significance remains unknown. In this study, we tested whether blink mimicry predicts preference using a naturalistic dyadic storytelling paradigm. One hundred and twenty participants, consisting of sixty female dyads, took turns as readers and listeners; readers read two movie synopses aloud while listeners observed their faces, then both indicated which synopsis they preferred. Blink events were extracted from continuous facial electromyography recordings, and mimicry was quantified by examining directional listener-following-reader coupling. Results showed that observed mimicry significantly exceeded chance levels established through permutation testing, demonstrating that blink mimicry occurs during naturalistic social interaction. Importantly, blink mimicry negatively predicted choice: synopses during which listeners more closely mimicked readers' blinks were less likely to be preferred. Listener blink rate alone did not predict preference. These findings position blink mimicry as part of the broader repertoire of joint action signals that emerge during face-to-face interaction. Blink mimicry may reflect an observer's attentional disengagement from content, offering a novel and easily measurable physiological marker of preference formation during naturalistic social exchange.