Elsevier

Human Movement Science

Volume 41, June 2015, Pages 240-254
Human Movement Science

Moving attractive virtual agent improves interpersonal coordination stability

https://doi.org/10.1016/j.humov.2015.03.012Get rights and content

Abstract

Interpersonal motor coordination is influenced not only by biomechanical factors such as coordination pattern, oscillating frequency, and individual differences, but also by psychosocial factor such as likability and social competences. Based on the social stereotype of “what is beautiful is good”, the present study aimed at investigating whether people coordinate differently with physically attractive people compared to less attractive people. 34 participants were engaged in an interpersonal coordination task with different looking (virtual) agents while performing at the same time a reaction time task. Results showed that participants had more stable motor coordination with the moving attractive than with the less attractive agent, and that the difference in motor coordination could not be interpreted by a specific attention allocation strategy. Our findings provide the evidence that physical attractiveness genuinely affects how people interact with another person, and that the temporal-spatial coordinated movement varies with the partner’s psychosocial characteristics. The study broadens the perspective of exploring the effect of additional psychosocial factors on social motor coordination.

Introduction

Motor coordination plays a fundamental role in our daily life. It enables individuals to efficiently synchronize with external environmental events as well as with other people during social interaction. Phenomena of motor coordination encompass for instances hand-clapping (Neda, Ravasz, Brechet, Vicsek, & Barabasi, 2000), two people walking together (van Ulzen, Lamoth, Daffertshofer, Semin, & Beek, 2008), and team sports such as basketball (Esteves et al., 2012).

In social context, our behavior is well coordinated temporally and spatially with the person(s) we are interacting with. Because of the cooperative nature of human relationship, two agents can be viewed as a single dyadic synergy (Schmidt, Carello, & Turvey, 1990). More than three decades’ research on interpersonal motor coordination has investigated the movement dynamics between people by adopting the model of the dynamical entrainment of two coupled oscillators. Relative phase, which captures the angular difference between two oscillators as a function of time (Haken et al., 1985, Kelso et al., 1986), summarizes the temporal spatial difference between the interactants’ movement. The standard deviation (SD) of relative phase depicts the variability of relative phases around their mean during the interaction process (Haken et al., 1985, Richardson et al., 2007). Lower SD of relative phase indicates higher stability of the coordination, and higher SD describes lower stability.

The majority of the studies conducted in the context of the dynamical approach to interpersonal motor coordination have focused on the biomechanical and neuromuscular factors shaping pattern formation. As in the bimanual coordination context, two natural patterns of interpersonal coordination co-exist: in-phase (relative phase = 0°) and anti-phase (relative phase = 180°). In-phase coordination is more stable than anti-phase, and a (between-people) phase transition occurs from anti-phase to in-phase when the oscillating frequency is elevated to a threshold value (Schmidt et al., 1998a, Schmidt et al., 1990). Moreover, when two interacting people share the same preferred frequency, coordination is the most stable, as large difference between two interactants’ preferred frequencies is more likely to lead to breakdowns in motor coordination (Richardson et al., 2007, Schmidt et al., 1998b).

As mentioned above, interpersonal motor coordination is influenced by biomechanical factors such as the type of coordination pattern (in-phase or anti-phase) (Schmidt et al., 1990), the oscillating frequency (Schmidt et al., 1990), and individual differences (Richardson et al., 2007, Schmidt et al., 1998b). Psychosocial factors, which are elements seemingly unrelated to biomechanical properties – such as social competence (Schmidt, Christianson, Carello, & Baron, 1994) and social motives (Lumsden, Miles, Richardson, Smith, & Macrae, 2012) – were reported to influence the performance of interpersonal coordination. Schmidt et al. (1994) explored whether social competence exerted any impact on visual interpersonal coordination of rhythmic limb movements. Participants were paired to form three types of combination of social competence: high-high (HH), high-low (HL), and low-low (LL). Results demonstrated that the HL combination produced fewer breakdowns in phase locking than the HH and LL pairs did (Schmidt et al., 1994). Lumsden et al. (2012) explored whether the degree of spontaneous synchronization with others can be modulated by social motives. People with a pro-social orientation showed a higher orientation to synchronize with others compared to the pro-self individuals (Lumsden et al., 2012). These two studies provide evidences that human beings’ temporal-spatial coordinated behavior is influenced by psychosocial factors, and that the way we interact with others reflects some of our psychological features.

Interestingly, the relationship between interactants has been broadly reported to affect and to be affected by interpersonal coordination. For instance, higher perceived movement synchrony was found to be associated with higher rapport between teacher and student (Bernieri, 1988). Miles, Nind, and Macrae (2009) demonstrated that the way individuals coordinate with each other reflects their mental connectedness. In their study, participants evaluated the rapport level of two walkers either by looking at a video of two animated walking images or by listening to auditory recordings of walking steps. Results showed that the highest third-party judgment of rapport was obtained when perceiving the most stable forms of interpersonal coordination (i.e., in-phase or anti-phase coordination) (Miles et al., 2009). In another experiment, the same group of researchers indicated that rapport resulted in higher level of motor coordination. Participants performed a stepping task in the presence of either a late-coming or a punctual confederate. Results showed that the late-coming confederate induced less rapport and lower degree of coordination compared to the on-time confederate. Moreover, a positive correlation between rapport and the level of coordination was found (Miles, Griffiths, Richardson, & Macrae, 2010). On the other hand, Hove et al. (2009) claimed that interpersonal coordination promotes likability. In their study, participants performed a finger-tapping task while sitting aside to a confederate who was either tapping synchronously or asynchronously with them, or stayed silent. Their results exhibited a higher level of likability in the synchronous condition than in the other two situations (Hove & Risen, 2009). Together, these studies suggest that coordinated behavior and interpersonal relationship are highly integrated. The way people coordinate with each other conveys information about the likability between interactants and influences it. At the same time, the likability between interacting partners may exert an impact on temporal-spatial coordinated movements during interpersonal interaction.

The focus of our study was to explore whether the coordinated behavior differs with the partner’s physical appearance, more specifically with physical attractiveness. The idea emerged from the Gibsonian notion of social perception, suggesting that individuals use others’ physical appearance to guide their behavior (Zebrowitz & Collins, 1997). Human appearance during social interaction can be viewed as a social affordance because what a person “invites, promises, threatens, or does can be found in (the information contained in) light” (Gibson, 1979). Furthermore, previous research has indeed found evidences for the phenomenon that individuals perceive and behave differently with attractive faces compared to less attractive faces. However, no consensus has been reached concerning whether physical attractiveness brings more positive or more negative effects. For example, some studies showed that men sought less help from attractive than unattractive women (Nadler, Shapira, & Ben-Itzhak, 1982). Physically attractive individuals were negatively evaluated by the same-gender counterparts in romantic contexts (Maner, Miller, Rouby, & Gailliot, 2009). On the contrary, in most cases, physical attractiveness exhibits advantages. Physically attractive faces were reported to win more help (Benson, Karabenick, & Lerner, 1976), higher likability (Byrne, London, & Reeves, 1968), and higher appraisal (Landy & Sigall, 1974) from perceivers compared to less attractive ones. In social psychology, the famous social stereotype of “what is beautiful is good” indicates that attractive appearance alone is powerful enough to evoke positive overgeneralizing effect. People tend to perceive physically attractive people as happier, outgoing, successful, kinder, and more intelligent, and have more favorable personal traits (Dion, Walster, & Berschei, 1972).

To sum up, individuals coordinate their movements during social interaction. As social agents, our between-person motor coordination is not only affected by biomechanical factors, but also by psychosocial characteristics of the people with whom we interact. Physical attractiveness, which can be considered as a social affordance, has been widely studied to influence the judgments and behavior of other people. However, no study so far has been conducted to explore whether physical attractiveness genuinely evokes different coordinated behavior during social interaction. Specifically our study aimed at investigating whether people adjust their motor behavior as a function of the social attractiveness of their interacting partner.

As more attention is often paid to physically attractive people (Lorenzo, Biesanz, & Human, 2010) and higher level of attention has been reported to increase interpersonal coordination performance (Richardson et al., 2007, Schmidt and O’Brien, 1997), we added a reaction time (RT) task to investigate whether the difference in coordination stability could be explained by the attention allocation strategy. A red dot on the face of the agent was displayed for the RT task, and it also assured that participants noticed the physical attractiveness of the agent.

Two questions were addressed: (1) whether motor coordination stability was different with attractive compared to less attractive agent; (2) whether the difference in motor coordination was due to attention allocation. We hypothesized that coordination would be more stable during coordination with the attractive agent, and that participants would pay more attention to coordinate with the attractive agent, thus leaving less attention to the RT task.

An attractive and a less attractive agent were used as coordination partners. Human-agent interaction instead of real human-human interaction was adopted to eliminate the possible interpretation that higher stability of motor coordination with the attractive agent was due to the similarity in preferred frequency (Schmidt et al., 1998b). Therefore in order to make sure that physical attractiveness was the only manipulated factor, artificial agents (in the present study they were pictures and videos) provided us with the possibility to assign exactly the same movement to agents with different physical attractiveness.

In the present study, both pictures and videos were employed to seek whether the agent’s moving status was critical in facilitating motor coordination based on the following two reasons. First, the findings of the mirror neuron system (Rizzolatti et al., 1996) suggest a strong neurological basis for interpersonal motor coordination. It illustrates the human nature of synchronizing with others when the perception of other’s behavior becomes available. Furthermore, studies using neuroimaging technology to compare the effect of static versus dynamic event showed that videos evoked higher activity in the related brain areas (Kessler et al., 2011, LaBar et al., 2003), indicating that perceiving movement stimulates the brain to a higher extent. Due to the close perception-action connection in the mirror neuron system, higher stimulation of the neural structures by perceiving movement is more likely to evoke execution of the perceived action. Therefore we hypothesized that videos might induce higher level of coordinated movements than pictures. Second, moving characteristic is a strong social affordance, which invites participants to coordinate more with the movements of their interactants. In the study of Aguiar and Taylor (2014) investigating children’s concepts of social affordance of a stuffed dog (static) compared to a virtual dog (moving), results showed that a virtual dog was rated higher in terms of inviting children to interact with them than the static dog (Aguiar & Taylor, 2014). It has been suggested that the moving characteristic provides a “live” experience, which affords more interactive behavior.

Section snippets

Participants

18 women and 16 men ranging in age from 15 to 31 (M = 22 years) were recruited into the experiment. Two participants were left-handed. Each participant signed the informed consent prior to the start of the experiment, and they were not told the real purpose of the experiment until it was finished. The study conforms to the principles expressed in the Declaration of Helsinki.

Displayed stimuli

In our experiment, seven displayed stimuli consisting of three videos and four pictures were adopted to show moving and

Stability of motor coordination

A 2 (pattern) × 2 (velocity) × 7 (display) repeated-measure ANOVA, completed by Fisher LSD post-hoc tests, was carried out on SD of relative phase. It revealed a significant main effects of pattern (F(1, 31) = 180, p < .01) and velocity (F(1, 31) = 24, p < .01). These effects demonstrated that participants had more stable coordination with in-phase compared to anti-phase, and at 100% compared to 150% of the preferred frequency. Representative times series of the four conditions of motor coordination are

Discussion

This study investigated whether interpersonal coordination is affected by the physical attractiveness of an interacting partner. The results confirmed previous findings that in-phase rhythmic coordination is more stable than anti-phase (Schmidt et al., 1990, Schmidt et al., 1998a), and that rhythmic coordination at a preferred frequency is more stable than at a faster frequency (Schmidt et al., 1994). More remarkably, we showed that participants had significantly higher coordination stability

Conclusion

To date, our study shows a direct link between moving physical attractiveness and motor coordination, confirming our intuition that the physical attractiveness modifies the way people move during social interaction. It broadens the possibility for investigating additional psychosocial properties that could affect one’s social behavior.

Funding/financial disclosure

This research was supported by AlterEgo, a project funded by the European Union [Grant Number 600610].

None of the authors have a financial interest in any of the products, devices, or drugs mentioned in this manuscript.

References (48)

  • D.H. Brainard

    The psychophysics toolbox

    Spatial Vision

    (1997)
  • D. Byrne et al.

    Effects of physical attractiveness sex and attitude similarity on interpersonal attraction

    Journal of Personality

    (1968)
  • K. Dion et al.

    What is beautiful is good

    Journal of Personality and Social Psychology

    (1972)
  • P.T. Esteves et al.

    Interpersonal dynamics and relative positioning to scoring target of performers in 1 vs. 1 sub-phases of team sports

    Journal Sports Sciences

    (2012)
  • F. Ferri et al.

    Social requests and social affordances: How they affect the kinematics of motor sequences during interactions between conspecifics

    PLoS One

    (2011)
  • C. Gianelli et al.

    Acting in perspective: The role of body and language as social tools

    Psychological Research-Psychologische Forschung

    (2013)
  • J.J. Gibson

    The ecological approach to visual perception

    (1979)
  • H. Haken et al.

    A theoretical model of phase transitions in human hand movements

    Biological Cybernetics

    (1985)
  • M.J. Hove et al.

    It’s all in the timing: Interpersonal synchrony increases affiliation

    Social Cognition

    (2009)
  • J.A.S. Kelso et al.

    On the nature of human interlimb coordination

    Science

    (1979)
  • H. Kessler et al.

    Neural correlates of the perception of dynamic versus static facial expressions of emotion

    Psychosocial Medicine

    (2011)
  • M. Kleiner et al.

    What’s new in Psychtoolbox-3?

    Perception

    (2007)
  • K.S. LaBar et al.

    Dynamic perception of facial affect and identity in the human brain

    Cerebral Cortex

    (2003)
  • D. Landy et al.

    Beauty is talent: task evaluation as a function of the performer’s physical attractiveness

    Journal of Personality and Social Psychology

    (1974)
  • Cited by (0)

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