This study explored the association between interpersonal attraction and behavioral synchrony among previously unacquainted pairs. Behavioral synchrony represents mutually attuned movement that occurs between individuals during dyadic engagement. Although previous research has found a positive link between these variables, the key dimension of interpersonal attraction that may be driving this relationship has yet to be identified. Young adult participants who were previously unacquainted were randomly paired to interact in an environment that emulated speed dating. Following the interaction, participants individually completed an inventory of their attraction to one another. Researchers observed their interactions and coded for synchronous behavior. Results supported only a significant relationship between task attraction (the degree to which an individual is evaluated as facilitative in goal achievement) and behavioral synchrony. This relationship persisted even when controlling for the other dimensions of interpersonal attraction: physical attraction and social attraction. By isolating task attraction as the single dimension positively associated with behavioral synchrony, this study distinguishes a possible key underlying motive (i.e., goal attainment) for a previously supported relationship to interpersonal attraction. These findings provide support for the newly proposed, unifying theory of interpersonal attraction guided by instrumentality. (PsycINFO Database Record (c) 2019 APA, all rights reserved)