Interpersonal Synchrony: A Survey of Evaluation Methods across Disciplines <s> Functions in Adulthood <s> Abstract Sound films of social interaction are analysed and some detailed descriptions of the interrelations of the movements of speakers ans listeners are given. These descriptions provide further examples of ‘interactional synchrony’, first described by Condon and Ogston (1966). It is found that the flow of movement in the listener may be rhythmically coordinated with the speech and movements of the speaker. It is also shown how the way in which individuals may be in synchrony with one another can vary, and that these variations are related to their respective roles in the interaction. Some of the implications of the phenomenon of interactional synchrony are discussed. <s> BIB001 </s> Interpersonal Synchrony: A Survey of Evaluation Methods across Disciplines <s> Functions in Adulthood <s> The chameleon effect refers to nonconscious mimicry of the postures, mannerisms, facial expressions, and other behaviors of one's interaction partners, such that one's behavior passively and unintentionally changes to match that of others in one's current social environment. The authors suggest that the mechanism involved is Has. perception-behavior link, the recently documented finding (e.g., J. A. Bargh, M. Chen, & L. Burrows, 1996) that the mere perception of another's behavior automatically increases the likelihood of engaging in that behavior oneself. Experiment 1 showed that the motor behavior of participants unintentionally matched that of strangers with whom they worked on a task. Experiment 2 had confederates mimic the posture and movements of participants and showed that mimicry facilitates the smoothness of interactions and increases liking between interaction partners. Experiment 3 showed that dispositionally empathic individuals exhibit the chameleon effect to a greater extent than do other people. <s> BIB002 </s> Interpersonal Synchrony: A Survey of Evaluation Methods across Disciplines <s> Functions in Adulthood <s> Background: Coordination of nonverbal behaviour during interactions is a prerequisite for satisfactory relationships. Lack of coordination may form a risk factor for depression. The 'vulnerability-accumulation hypothesis' assumes that vulnerability to recurrence of depression will increase with increasing experience of depressive episodes. Therefore it is expected that interviewers and patients remitted from a recurrent episode of depression would reach less coordination during a clinical interview compared to interviewers and patients remitted from a first Lifetime episode. Moreover, we assumed that prior severity of depression modifies this reciprocal coordination process. Methods: During discharge interviews, interviewers were videotaped in interaction with remitted patients with unipolar major depression recurrent depression (REC); n = 28; first episode (SEP); n = 22. Durations and frequencies of nonverbal involvement behaviour was registered during the first 15 min. Involvement of the patients consisted of gesticulating, looking at the interviewer, and general head movements; yes nodding and hm, hm, yes, yes reflected involvement of the interviewer. Coordination between patients and interviewers was analyzed per S-min epochs and defined as 'attunement': the absolute difference between patients' and interviewers' involvement. Averaged attunement, its time course and variability (presumably reflecting control of the attunement process) were assessed. Results: The time course of nonverbal attunement differed between the REC and SEP condition. A larger variability of attunement was found in patients remitted from a relatively severely depressed episode, compared to patients remitted from a seven first life time episode. No other significant differences were found. Conclusions: Partial support was found for the notion that nonverbal vulnerability accumulates in depression and that the severity of prior depression modifies this process. (C) 2000 Elsevier Science B.V. All rights reserved. <s> BIB003 </s> Interpersonal Synchrony: A Survey of Evaluation Methods across Disciplines <s> Functions in Adulthood <s> The existence of a specialized imitation module in humans is hotly debated. Studies suggesting a specific imitation impairment in individuals with autism spectrum disorders (ASD) support a modular view. However, the voluntary imitation tasks used in these studies (which require socio-cognitive abilities in addition to imitation for successful performance) cannot support claims of a specific impairment. Accordingly, an automatic imitation paradigm (a ‘cleaner’ measure of imitative ability) was used to assess the imitative ability of 16 adults with ASD and 16 non-autistic matched control participants. Participants performed a prespecified hand action in response to observed hand actions performed either by a human or a robotic hand. On compatible trials the stimulus and response actions matched, while on incompatible trials the two actions did not match. Replicating previous findings, the Control group showed an automatic imitation effect: responses on compatible trials were faster than those on incompatible trials. This effect was greater when responses were made to human than to robotic actions (‘animacy bias’). The ASD group also showed an automatic imitation effect and a larger animacy bias than the Control group. We discuss these findings with reference to the literature on imitation in ASD and theories of imitation. <s> BIB004 </s> Interpersonal Synchrony: A Survey of Evaluation Methods across Disciplines <s> Functions in Adulthood <s> Abstract While previous research has demonstrated that people’s movements can become coordinated during social interaction, little is known about the cognitive consequences of behavioral synchrony. Given intimate links between the systems that regulate perception and action, we hypothesized that the synchronization of movements during a dyadic interaction may prompt increased attention to be directed to an interaction partner, hence facilitate the information that participants glean during a social exchange. Our results supported this prediction. Incidental memories for core aspects of a brief interaction were facilitated following in-phase behavioral synchrony. Specifically, participants demonstrated enhanced memory for an interaction partner’s utterances and facial appearance. These findings underscore the importance of action perception to social cognition. <s> BIB005 </s> Interpersonal Synchrony: A Survey of Evaluation Methods across Disciplines <s> Functions in Adulthood <s> The temporal coordination of behavior during dyadic interactions is a foundation for effective social exchange with synchronized actions enhancing perceptions of rapport and interpersonal connectedness. What has yet to be established, however, are the precise characteristics of behavioral coordination that give rise to such effects. Informed by a dynamical systems approach, the current investigation considered whether judgments of rapport are influenced by the mode of interpersonal synchrony. In two experiments, participants rated the degree of rapport manifest by a simulated pair of walkers exhibiting various configurations of synchronized strides. The results revealed that the highest levels of rapport were associated with the most stable forms of interpersonal coordination (i.e., in-phase and anti-phase synchrony), regardless of whether coordination between the walkers was conveyed via the presentation of visual (Expt. 1a) or auditory (Expt. 1b) cues. These findings underscore the importance of interpersonal coordination to core aspects of social perception. <s> BIB006 </s> Interpersonal Synchrony: A Survey of Evaluation Methods across Disciplines <s> Functions in Adulthood <s> Armies, churches, organizations, and communities often engage in activities—for example, marching, singing, and dancing—that lead group members to act in synchrony with each other. Anthropologists and sociologists have speculated that rituals involving synchronous activity may produce positive emotions that weaken the psychological boundaries between the self and the group. This article explores whether synchronous activity may serve as a partial solution to the free-rider problem facing groups that need to motivate their members to contribute toward the collective good. Across three experiments, people acting in synchrony with others cooperated more in subsequent group economic exercises, even in situations requiring personal sacrifice. Our results also showed that positive emotions need not be generated for synchrony to foster cooperation. In total, the results suggest that acting in synchrony with others can increase cooperation by strengthening social attachment among group members. <s> BIB007 </s> Interpersonal Synchrony: A Survey of Evaluation Methods across Disciplines <s> Functions in Adulthood <s> Nonverbal behavior plays an important role in human-human interaction. One particular kind of nonverbal behavior is mimicry. Behavioral mimicry supports harmonious relationships in social interaction through creating affiliation, rapport, and liking between partners. Affective computing that employs mimicry knowledge and that is able to predict how mimicry affects social situations and relations can find immediate application in human-computer interaction to improve interaction. In this short paper we survey and discuss mimicry issues that are important from that point of view: application in human-computer interaction. We designed experiments to collect mimicry data. Some preliminary analysis of the data is presented. <s> BIB008 </s> Interpersonal Synchrony: A Survey of Evaluation Methods across Disciplines <s> Functions in Adulthood <s> Movement synchrony has been theoretically linked to the emergence of a social unit. To empirically investigate whether similar movement rhythms are an antecedent of perceived entitativity, movement rhythms were experimentally manipulated in four studies. Using this novel approach, stick figures waving in synchrony were found to be rated higher on entitativity than stick figures waving in different rhythms (Study 1), and this effect was extended to interactional synchrony, where different movements are performed in the same rhythm (Study 2). Objective differences in movement rhythms are linearly related to ratings of perceived entitativity, and this relationship is partially mediated by the subjectively perceived similarity of movement rhythms (Study 3). These results also held for entitativity judgments for videotaped individuals waving rhythmically (Study 4). These results support the hypothesis that movement rhythms are an important source of information which observers use to infer the extent to which individuals are a social unit. <s> BIB009 </s> Interpersonal Synchrony: A Survey of Evaluation Methods across Disciplines <s> Functions in Adulthood <s> 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. <s> BIB010 </s> Interpersonal Synchrony: A Survey of Evaluation Methods across Disciplines <s> Functions in Adulthood <s> Objective: The authors quantified nonverbal synchrony—the coordination of patient's and therapist's movement—in a random sample of same-sex psychotherapy dyads. The authors contrasted nonverbal synchrony in these dyads with a control condition and assessed its association with session-level and overall psychotherapy outcome. Method: Using an automated objective video analysis algorithm (Motion Energy Analysis; MEA), the authors calculated nonverbal synchrony in (n = 104) videotaped psychotherapy sessions from 70 Caucasian patients (37 women, 33 men, mean age = 36.5 years, SD = 10.2) treated at an outpatient psychotherapy clinic. The sample was randomly drawn from an archive (N = 301) of routinely videotaped psychotherapies. Patients and their therapists assessed session impact with self-report postsession questionnaires. A battery of pre- and postsymptomatology questionnaires measured therapy effectiveness. Results: The authors found that nonverbal synchrony is higher in genuine interactions contrasted with pseudointeractions (a control condition generated by a specifically designed shuffling procedure). Furthermore, nonverbal synchrony is associated with session-level process as well as therapy outcome: It is increased in sessions rated by patients as manifesting high relationship quality and in patients experiencing high self-efficacy. Higher nonverbal synchrony characterized psychotherapies with higher symptom reduction. Conclusions: The results suggest that nonverbal synchrony embodies the patients' self-reported quality of the relationship and further variables of therapy process. This hitherto overlooked facet of therapeutic relationships might prove useful as an indicator of therapy progress and outcome. <s> BIB011
In adulthood, interactional synchrony has been shown to act as a facilitator to smooth social interactions, to achieve "coordination of expectancies among participants" BIB001 . Nonverbal synchrony also plays a role in building rapport among individuals  , BIB008 . In their study of nonconscious mimicry, Chartrand and Bargh established a link between the degree of mimicry, the perception of interaction smoothness, and the degree of liking between interaction partners BIB002 . Moreover, they showed that not all individuals share the same dispositions to imitate their partners and that empathic persons had a greater tendency to produce nonconscious mimicry. A link has also been established between the degree of synchrony and how dyadic partners are perceived BIB006 . For instance, Lakens manipulated movement rhythms of stick figures and asked judges to evaluate the perceived entitativity (i.e., the unity, the emergence of a social unit). He demonstrated a linear relationship between the differences of movement rhythms and the perception of entitativity BIB009 . Executing a task in synchrony seems to promote cooperation between individuals BIB007 and to enhance memory of the interaction partner's utterances and face appearance BIB005 . More, in-phase coordination was shown to promote memory of the interaction partner's utterances over self-utterances BIB010 . Interestingly, Ramseyer and Tschacher, investigating nonverbal synchrony between patient and therapist during psychotherapy sessions, showed that nonverbal synchrony was associated with session-level processing and therapy outcome BIB011 . They found higher synchrony in sessions rated by patients as manifesting high relationship quality and in patients experiencing high self-efficacy. Furthermore, higher nonverbal synchrony was observed in psychotherapies with higher symptom reduction. Bouhuys and Sam found that a lack of coordination in nonverbal behaviors constitutes a risk factor for depression recurrence BIB003 . In addition, Bird et al., comparing adults with Autism Spectrum Disorders (ASD) to controls in an imitation task, found that ASD individuals responded faster to robotic hands, whereas the comparison group responded faster to human hands BIB004 .