A theory of flexible multimodal synchrony.

Dominant theoretical accounts of interpersonal synchrony, the temporal coordination of biobehavioral processes between several individuals, have employed a linear approach, generally considering synchrony as a positive state, and utilizing aggregate scores. However, synchrony is known to take on a dynamical form with continuous shifts in its timeline. Acting as one continuously, is not always the optimal state, due to an intrinsic tension between individualistic and synergistic forms of action that exist in many social situations. We propose an alternative theory of flexible multimodal synchrony which highlights context as a key component that defines "pulls" toward synchrony and "pulls" toward segregation inherent to the social situation. Traitlike individual differences and relationship variables then sensitize individuals to these contextual "pulls." In this manner, context, individual differences, and relationship variables provide the backdrop to the emergence of flexible and dynamical synchrony patterns, which we consider adaptive, in several modalities-behavioral, physiological, and neural. We point to three consequences of synchrony patterns: social-, task, and self-oriented. We discuss multimodal associations that arise in different contexts considering the theory and delineate hypotheses that emanate from the theory. We then provide two empirical proofs-of-concept: First, we show how individual differences modulate the effect of context on synchrony's outcomes in a novel dyadic motor game. Second, we reanalyze previously reported data, to show how a "flexibility" approach to synchrony data analysis improves predictive ability when testing for synchrony's effects on social cohesion. We provide ways to standardize the characterization of context and guidelines for future synchrony research. (PsycInfo Database Record (c) 2025 APA, all rights reserved).