Moving memories: Behavioral synchrony and memory for self and others

Abstract

Establishing and maintaining connections with others is central to a fulfilling social life. In this respect, behavioral coordination provides one avenue by which interpersonal linkages can be formed. Drawing from the dynamical systems approach, the present research explored whether temporary interpersonal connections founded on coordinated behavior influence memory for self and others. To do so, we measured participants’ incidental recall of self and other-relevant information after a period of either in-phase or anti-phase interpersonal coordination. While participants in the less stable anti-phase condition demonstrated the typical memory advantage for self-related compared to other-related information, this effect was eliminated when participant and confederate movements displayed in-phase coordination. These results are discussed with respect to the interplay between the systems that support interpersonal synchrony and basic social-cognitive processing.

Introduction

From bonds forged through childhood friendships to the sparks of successful first dates, connecting with others is a cornerstone of human sociality. While such interpersonal linkages can be established via a variety of routes, one intriguing pathway centers on the physical movements that occur during social interaction. Put simply, the degree to which people’s movements are similar can impact how they feel about each other. Corroborating this observation, an extensive literature has demonstrated that by coordinating one’s actions with others through either imitation (e.g., Chartrand and Bargh, 1999, Lakin and Chartrand, 2003, van Baaren et al., 2009) or synchronization (e.g., Bernieri, 1988, Hove and Risen, 2009, LaFrance, 1979, Wiltermuth and Heath, 2009), positive social outcomes (e.g., liking, rapport, cooperation) can be achieved.

Alongside empirical demonstrations of the association between behavioral coordination and enhanced social connections (Semin, 2007, Semin and Cacioppo, 2008), research from the dynamical systems approach has revealed that interpersonal synchrony is characterized by two specific modes of coordination: in-phase and anti-phase (Haken et al., 1985, Schmidt et al., 1990). To illustrate, consider two children on swings. In-phase coordination would be evident if the swings were in perfect unison, such that both swings were maximally forward (or backward) at the same time. Alternatively, anti-phase coordination would display the opposite pattern, such that when one swing was maximally forward, the other would be maximally backward. Although the relationship between the positions of the swings could notionally take on any pattern, over time it would typically settle into one of these two attractor states (i.e., in-phase or anti-phase). As such, only in-phase and anti-phase movements characterize stable interpersonal synchrony (Schmidt and Richardson, 2008, Schmidt et al., 1990).

At a general level, in-phase and anti-phase coordination may serve distinct social functions. For instance, a rowing crew must coordinate in an in-phase manner by performing their strokes in unison, while a successful conversation depends on turn taking between speakers—that is, anti-phase coordination (Wilson & Wilson, 2005). Of relevance to the current investigation, recent research suggests that a specific property of coordination, namely its stability,¹ may influence fundamental aspects of social exchange. For example, stable coordination has been associated with enhanced rapport (Miles, Nind, & Macrae, 2009) and liking for interaction partners (Hove & Risen, 2009). In addition, Macrae, Duffy, Miles, and Lawrence (2008) demonstrated that memory for an interaction partner’s appearance and utterances were enhanced following in-phase, compared to anti-phase coordination.² Thus, it appears that beyond the broad relationship between behavioral coordination and positive social outcomes, the nature of the coordination itself (e.g., mode or stability) has significant bearing on core elements of social cognition. In particular, changes in the accuracy with which information about others is recalled (Macrae et al., 2008) points to a relationship between coordination mode and social interaction that is grounded in basic cognitive processes. This observation raises a number of interesting questions. Notably, if person perception is modulated by coordination mode, are other core social-cognitive phenomena influenced in a similar manner? To this end, we considered whether the processing of self-relevant information is impacted by the nature of interpersonal coordination.

The self-reference effect (SRE) in memory refers to the preferential encoding and memory for information related to the self compared to other people (Rogers et al., 1977, Symons and Johnson, 1997). Self-memory advantages have been demonstrated across a variety of task contexts and are associated with distinct patterns of neural activity (Macrae et al., 2004, Powell et al., in press). Importantly, however, when there is an existing social connection between self and others the magnitude of the self-memory advantage is typically attenuated (Symons & Johnson, 1997). For example, information about a close friend tends to be processed in an equivalent manner to self-relevant information. Pertinent to the present investigation, the self-memory effect provides a context in which the effects of coordination stability on social-cognitive functioning can be further illuminated. In particular, we suspect that social connections founded on interpersonal synchrony (Hove and Risen, 2009, Macrae et al., 2008, Marsh et al., 2009, Miles et al., 2009, Schmidt and Richardson, 2008), although temporary, may also impact memory performance. Specifically, the magnitude of self-memory effects may be modulated by the relative stability of interpersonal coordination (i.e., anti-phase > in-phase).