Physiological synchrony is associated with attraction in a blind date setting.

Humans are social animals whose well-being is shaped by the ability to attract and connect with one another, often through brief interactions. In addition to physical features, a choreography of movements, physical reactions and subtle expressions may help promote attraction. Here, we measured the physiological dynamics between pairs of participants during real-life dating interactions outside the laboratory. Participants wore eye-tracking glasses with embedded cameras and devices to measure physiological signals including heart rate and skin conductance. We found that overt signals such as smiles, laughter, eye gaze or the mimicry of those signals were not significantly associated with attraction. Instead, attraction was predicted by synchrony in heart rate and skin conductance between partners, which are covert, unconscious and difficult to regulate. Our findings suggest that interacting partners’ attraction increases and decreases as their subconscious arousal levels rise and fall in synchrony. Using a speed dating paradigm, Prochazkova et al. show that attraction was predicted by physiological synchrony in heart rate and skin conductance between two individuals.