Rhythms of interaction – the timescales of social synchrony and why they matter

Social interaction involves coordination between individuals across multiple domains, including neural activity, behaviour and physiology. An increasing number of studies shows that interpersonal synchrony can be detected in each of these modalities, but the functional significance of these different types of synchrony remains unclear. This paper examines the challenge of understanding synchrony in terms of the timescales of interaction. We provide a novel mapping of interaction types and measurement methods across timescales spanning from milliseconds to minutes. We review candidate mechanisms of synchrony in both neural systems and behaviour, and consider how synchrony measures relate to real world outcomes such as learning and development. Overall, we provide an integrative approach that, by taking timescales into account, aims to offer a better understanding of the origins and interpretation of interpersonal synchrony.