This article contains a review of modern foreign concepts and empirical studies of dyadic synchrony mechanism which manifests in temporal alignment of biological rhythms and behavior of individuals participating in a paired interaction. Due to the development of neuroimaging techniques, the interest in hyperscanning has increased, as it allows to register brain activity of two or more individuals capturing the mechanism of dyadic synchrony. In this article such manifestations of dyadic synchrony as changes in the electrical brain activity, cardiac rhythms, respiratory rate, hormonal levels, and behavior are described. Dyadic synchrony at the early stages of development underlies individuals’ ability to learn, feel empathy, develop attachment and build close relationships.