The Modulation of Mimicry by Ethnic Group-Membership and Emotional Expressions

Visible skin disease symptoms of another person reduce automatic imitation of their hand movements

Imitation is an important mechanism for social interaction and learning, and humans tend to imitate others automatically. While imitating others is often useful, it can backfire when imitation is incongruent with one's goals. For example, in forced-choice reaction time tasks, this tendency results in a reliable slowing of reactions if the observed and self-initiated actions are incompatible (compatibility effect). While imitation is commonly explained as a social phenomenon, previous results on the compatibility effect's dependence on social cues are inconsistent. However, in many previous studies, the associated social cues were easy to ignore by the participants. To make the social modifier more salient, the current study manipulated emotionally relevant aspects of the model hand itself in an imitation inhibition task by using models displaying skin disease symptoms which we expected to elicit (1) perceptions of dissimilarity and (2) disgust in participants. As predicted, participants' (n = 63) reaction times were influenced more by the incompatible actions of the symptom-free than the symptomatic model hand. However, both levels of self-reported disgust toward and self-other overlap with symptomatic hands were low and did not account for the observed effect on automatic imitation. Our findings show that automatic imitation depends on social factors if these are an integral part of the model and processed quickly, presumably due to their affective salience or the salience of the self-other distinction. Whether this effect is driven by emotional reactions to the model remains an open question.

“Emotional Proximity” and “Spatial Proximity”: Higher Relationship Quality and Nearer Distance Both Strengthen Scratch Contagion in Tibetan Macaques

Simple Summary

In social situations, people may unconsciously repeat their partners’ small moves. Sometimes we can not help opening our mouths when we watch others yawn; other times, we subconsciously cross our legs like others. This phenomenon also exists in animals. We believe that this retained habit is beneficial to social animals. By observing a group of macaques, we found that close partners are more prone to have behavioral synchronization, which is conducive to the maintenance of the group.

Abstract

Behavioral contagion has been defined as a phenomenon in which an unlearned behavior automatically triggers a similar behavior in others. Previous studies showed that a behavioral contagion might have the function of strengthening social relationships, promoting group coordination and maintaining social cohesion. However, so far, there are few studies investigating the correlation between contagious scratching and social bonding. Tibetan macaques (Macaca thibetana) live in multi-male and multi-female cohesive matrilineal groups, and scratching is usually observed in their affiliated interactions. We investigated the process of scratch contagion in one group of free-ranging Tibetan macaques and explored whether behavioral contagion could consolidate social relationships and maintain social stability. Results showed that the scratching was contagious and correlated with relationship quality and spatial distance. In dyads with a higher Dyadic Composite Sociality Index (DSI), the contagion was strong. In addition, contagions occurred more frequently and faster among individuals nearer to each other. In terms of social groups, members with higher social centrality participated in more behavioral contagion, whether as expressers or observers. Our findings provide new perspectives for studying behavioral contagions in humans and animals.

Emotional mimicry as social regulator: theoretical considerations

The goal of this article is to discuss theoretical arguments concerning the idea that emotional mimicry is an intrinsic part of our social being and thus can be considered a social act. For this, we will first present the theoretical assumptions underlying the Emotional Mimicry as Social Regulator view. We then provide a brief overview of recent developments in emotional mimicry research and specifically discuss new developments regarding the role of emotional mimicry in actual interactions and relationships, and individual differences in emotional mimicry. We conclude with open questions for future research.

Dining with liberals and conservatives: The social underpinnings of food neophobia

Although food and politics seem to be distant domains, socio-political ideology and food neophobia (i.e., reluctance to eat unfamiliar food) may be related. Conservatives’ high threat sensitivity and the inherently threatening nature of novel foods (the existential explanation), along with conservatives’ negative attitudes toward minority outgroups (e.g., foreigners) and the role of the latter in introducing novel foods to a culture (the social explanation), led us to expect that socio-political ideology would predict food neophobia over and above their common roots. Across two correlational and two experimental studies (N = 627), socio-political ideology emerged as a strong predictor of food neophobia. In addition, the findings did not support the existential explanation, while confirming the social explanation of the ideology–food neophobia link: Conservatives seem more neophobic than liberals not because of their higher threat sensitivity but rather because they hold more negative attitudes toward foreigners who are associated with those foods.

Imitation and interindividual differences: Belief in free will is not related to automatic imitation

It is well known that individuals have the tendency to automatically imitate each other and that such imitative behavior is fostered by perceiving intentions in others' actions. That is, past research has shown that perceiving an action as internally driven enhances the shared representation of observed and executed actions increasing automatic imitation. An interpersonal factor that increases the perception that a behavior is internally driven is belief in free will. Consequently, we hypothesized that the more individuals believe in free will, the more they automatically imitate others. To test this prediction, we conducted two high-powered (total N = 642) and preregistered studies in which we assessed automatic imitation with the imitation-inhibition task. Contrary to our predictions, belief in free will did not correlate with automatic imitation. This finding contributes to current findings challenging the assumption that automatic imitation is modulated by interindividual differences. Further theoretical implications are discussed.

Group membership does not modulate automatic imitation

Individuals have the automatic tendency to imitate each other. A key prediction of different theories explaining automatic imitation is that individuals imitate in-group members more strongly than out-group members. However, the empirical basis for this prediction is rather inconclusive. Only a few experiments have investigated the influence of group membership using classic automatic imitation paradigms and these experiments led to mixed results. To put the group membership prediction to a critical test, we carried out six high-powered experiments (total N = 1538) in which we assessed imitation with the imitation-inhibition task and manipulated group membership in different ways. Evidence across all experiments indicates that group membership does not modulate automatic imitation. Moreover, we do not find support for the idea that feelings of affiliation or perceived similarity moderate the effect of group membership on automatic imitation. These results have important implications for theories explaining automatic imitation and contribute to the current discussion of whether automatic imitation can be socially modulated.

Interplay of self-other distinction and cognitive control mechanisms in a social automatic imitation task: An ERP study

The regulation of motor resonance processes in daily life is indispensable. The automatic imitation task is an experimental model of those daily-life motor resonance processes. Recent research suggests that both self-other distinction and cognitive control processes may be involved in interference control during automatic imitation. Yet, we lack a clear understanding of the chronological sequence of interacting processes. To this end, this study used event-related potentials (ERPs) to investigate the time course underlying interference control during automatic imitation. We moreover aimed to extend previous results by investigating its modulation by social context. Cognitive conflict/action monitoring was assessed with the N2, in an exploratory manner the N450, and the CRN components. The Pre-Motor Positivity (PMP), associated with movement initiation, was suggested as a possible correlate of the successful resolution of self-other distinction. The cognitive control/action monitoring ERP components were influenced by the social context manipulation and partly by congruency, while PMP amplitudes were only sensitive to congruency. In addition, the exploratorily investigated N450 component predicted response times on incongruent relative to congruent trials in the different social contexts. This suggested that cognitive control/action monitoring processes, reflected in the N450, are guiding behavioral outcomes. Overall, interference control may primarily be guided by processes of cognitive control/action monitoring, whilst being modulated by social context demands.

Right Temporoparietal Junction Plays a Role in the Modulation of Emotional Mimicry by Group Membership

Our prior research demonstrated that the right temporoparietal junction (rTPJ) exerted a modulatory role in ingroup bias in emotional mimicry. In this study, two experiments were conducted to further explore whether the rTPJ is a neural region for emotional mimicry or for the modulation of emotional mimicry by group membership in a sham-controlled, double-blinded, between-subject design. Both experiments employed non-invasive transcranial direct current stimulation (tDCS) to temporarily change the cortical excitability over the rTPJ and facial electromyography (fEMG) to measure facial muscle activations as an index of emotional mimicry. After the anodal or sham stimulation, participants in Experiment 1 passively viewed a series of happy clips, while participants in Experiment 2 viewed happy clips performed by ethnic ingroup and outgroup models. fEMG analyses revealed that participants in Experiment 1 showed the same degree of happy mimicry for both tDCS conditions (anodal vs. sham) and participants in Experiment 2 showed an ingroup bias in happy mimicry in the sham condition, which disappeared in the anodal condition. Taken together, the present study demonstrated that rTPJ plays a role in the modulation of emotional mimicry by group membership.

Imitation in one's own presence: No specific effect of self-focus on imitation

Previous studies have reported that imitative responses may be modulated by top-down social factors such as self-focus. However, growing evidence suggests that such social factors may actually modulate domain-general processes such as spatially compatible responding, rather than specifically social processes such as imitation. In this study, we aimed to identify the cognitive processes being modulated under conditions of heightened or diminished self-focus. Participants performed a stimulus-response compatibility task which independently measures both spatial and imitative response tendencies, under two conditions: heightened self-focus, where the task was performed in the presence of two mirrors; and diminished self-focus, where the mirrors were covered. While participants were faster to respond to compatible trials than to incompatible trials, both imitatively and spatially, there was no significant modulation of either spatial or imitative compatibility by self-focus; although the magnitude of the modulation of spatial compatibility was numerically similar to the effect of self-focus on imitation found in previous studies. These results provide no evidence for an effect of self-focus on either social-specific, or domain-general, processes.

Dynamic emotional expressions do not modulate responses to gestures

The tendency to imitate the actions of others appears to be a fundamental aspect of human social interaction. Emotional expressions are a particularly salient form of social stimuli (Vuilleumier & Schwartz, 2001) but their relationship to imitative behaviour is currently unclear. In this paper we report the results of five studies which investigated the effect of a target's dynamic emotional stimuli on participants' tendency to respond compatibly to the target's actions. Experiment one examined the effect of dynamic emotional expressions on the automatic imitation of opening and closing hand movements. Experiment two used the same basic paradigm but added gaze direction as an additional factor. Experiment three investigated the effect of dynamic emotional expressions on compatibility responses to handshakes. Experiment four investigated whether dynamic emotional expressions modulated response to valenced social gestures. Finally, experiment five compared the effects of dynamic and static emotional expressions on participants' automatic imitation of finger lifting. Across all five studies we reliably elicited a compatibility effect however, none of the studies found a significant modulating effect of emotional expression. This null effect was also supported by a random effects meta-analysis and a series of Bayesian t-tests. Nevertheless, these results must be caveated by the fact that our studies had limited power to detect effect sizes below d = 0.4. We conclude by situating our findings within the literature, suggesting that the effect of emotional expressions on automatic imitation is, at best, minimal.

Self-categorization as a basis of behavioural mimicry: Experiments in The Hive

INTRODUCTION

Do we always do what others do, and, if not, when and under what conditions do we do so? In this paper we test the hypothesis that mimicry is moderated by the mere knowledge of whether the source is a member of the same social category as ourselves.

METHODS

We investigated group influence on mimicry using three tasks on a software platform which interfaces with mobile computing devices to allow the controlled study of collective behaviour in an everyday environment.

RESULTS

Overall, participants (N = 965) were influenced by the movements of confederates (represented as dots on a screen) who belonged to their own category in both purposive and incidental tasks.

CONCLUSION

Our results are compatible with collective level explanations of social influence premised on shared social identification. This includes both a heuristic of unintended mimicry (the acts of group members are diagnostic of how one should act), and communication of affiliation (based on a desire to make one's group cohesive). The results are incompatible with traditional 'contagion' accounts which suggest mimicry is automatic and inevitable. The results have practical implications for designing behavioural interventions which can harness the power of copying behaviour, for example in emergency evacuations.

Challenges and opportunities for top-down modulation research in cognitive psychology

Studying social modulation of cognitive processes holds much promise for illuminating how, where, when and why social factors influence how we perceive and act in the world, as well as providing insight into the underlying cognitive mechanisms. This is no small objective; it reflects an ambitious programme of research. At present, based on the modal theoretical and methodological approach, we suggest that several challenges exist to achieving such lofty aims. These challenges span an overreliance on a simplistic dichotomy between "top-down" and "bottom-up" modulation, a lack of specificity about mechanisms that renders clear interpretations difficult, and theories that largely test against null hypotheses. We suggest that these challenges present several opportunities for new research and we encourage the field to abandon simplistic dichotomies and connect much more with existing research programmes such as semantics, memory and attention, which have all built diverse research platforms over many decades and that can help shape how social modulation is conceptualised and studied from a cognitive and brain perspective. We also outline ways that stronger theoretical positions can be taken, which avoid comparing to null hypotheses, and endorse methodological reform through fully embracing proposals from the open science movement and "credibility revolution". We feel that by taking these opportunities, the field will have a better chance of reaching its potential to build a cumulative science of social modulation that can inform understanding of basic cognitive and brain systems, as well as real-life social interactions and the varied abilities observed across the Autism Spectrum.

Being mimicked affects inhibitory mechanisms of imitation

This study investigated the effects of being mimicked on automatic imitation indices and social cohesion. 180 female participants were either interactively mimicked or anti-mimicked. In the mimicry condition, a confederate topographically aligned, during anti-mimicry, misaligned, their behavior to the participants. Being mimicked may evoke a sense of overlap between self and other generated movements. This so-created self-other overlap may generalize to other forms of imitation and social cohesion. Here, we investigated the effects of being mimicked on automatic imitation indices, using the Imitation-Inhibition Task. These indices are the baseline corrected facilitation and inhibition index, and the interference index which depicts the relation between facilitation and inhibition. In case of a generalized self-other overlap, we expect an increase in the facilitation, inhibition, and interference index, after the Mimicry as compared to the Anti-Mimicry condition. We furthermore predicted that the modulation of the indices would predict higher social cohesion ratings. Yet, our results showed a lower inhibition index after being mimicked, respectively an increase after Anti-Mimicry, with no effects on social cohesion ratings. This suggests that potential self-other overlap after being mimicked does not generalize to automatic imitation indices. Instead, being mimicked may have increased self-regulatory processes, and task performance.

Right Temporoparietal Junction Modulates In-Group Bias in Facial Emotional Mimicry: A tDCS Study

The present study employs transcranial direct current stimulation (tDCS), a non-invasive brain stimulation technique, to explore the possible role of the right temporoparietal junction (rTPJ) in regulating in-group bias in facial emotional mimicry. Participants received either anodal or cathodal stimulation, or they were assigned to a sham condition. After that, they passively viewed a series of video clips depicting different emotions (happiness and anger) that were performed either by ethnic in-group or out-group models. The emotion-specific muscle activities, zygomatic major (ZM) and corrugator supercilii (CS) were recorded simultaneously as the index of facial emotional mimicry. The results first confirm the in-group bias in facial emotional mimicry in the sham condition, as shown in prior studies, though it only occurs in happy mimicry. Moreover, the in-group bias in facial emotional mimicry is modulated by the cortical excitability over the rTPJ, which may be attributed to the accompanied change of overlap of the mental representations of in-group and out-group. This study provides a close look at the neural underpinning of the modulation of facial emotional mimicry by group membership and highlights the role of rTPJ in on-line control of co-activated self and other representations in social cognition.

Developmental trajectory of interpersonal motor alignment: Positive social effects and link to social cognition

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Interpersonal motor alignment (IMA) has positive effects on healthy social life.

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IMA - mimicry, synchrony, automatic imitation - is studied throughout development.

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It relies on motor resonance brain mechanisms identified throughout development.

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It is modulated by contextual and personal factors.

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IMA is underinvestigated in adolescence, yet it may aid to enhance resilience.

Interpersonal motor alignment is a ubiquitous behavior in daily social life. It is a building block for higher social cognition, including empathy and mentalizing and promotes positive social effects. It can be observed as mimicry, synchrony and automatic imitation, to name a few. These phenomena rely on motor resonance processes, i.e., a direct link between the perception of an action and its execution. While a considerable literature debates its underlying mechanisms and measurement methods, the question of how motor alignment comes about and changes in ontogeny all the way until adulthood, is rarely discussed specifically. In this review we will focus on the link between interpersonal motor alignment, positive social effects and social cognition in infants, children, and adolescents, demonstrating that this link is present early on in development. Yet, in reviewing the existing literature pertaining to social psychology and developmental social cognitive neuroscience, we identify a knowledge gap regarding the healthy developmental changes in interpersonal motor alignment especially in adolescence.

Low relationship quality predicts scratch contagion during tense situations in orangutans (Pongo pygmaeus)

Primates show various forms of behavioral contagion that are stronger between kin and friends. As a result, behavioral contagion is thought to promote group coordination, social cohesion, and possibly state matching. Aside from contagious yawning, little is known about the contagious effect of other behaviors. Scratching is commonly observed during arousal and as such may play a role within group dynamics. While the Bornean orangutan (Pongo pygmaeus) is commonly considered the least social great ape, orangutans do engage in social interactions. Therefore, their social organization makes them a suitable case for studying the social function of behavioral contagion. Through behavioral observations of captive orangutans, we recorded all yawn and scratch events together with the corresponding behavior of all bystander group-members. As yawning was rarely observed, no conclusions could be drawn regarding this behavior. Scratching was contagious and occurred within 90 s after the triggering scratch. Specifically, orangutans showed increased scratch contagion when they had seen a weakly bonded individual scratch during tense contexts. When the orangutan had not seen the triggering scratch, the contagiousness of scratching was not affected by context or relationship quality. Our results indicate that behavioral contagion is not simply higher between individuals with stronger social relationships, but that the contagiousness of behaviors may vary based on the context and on social factors. We discuss these findings in light of an adaptive function that may reduce aggression.

Unfolding political attitudes through the face: facial expressions when reading emotion language of left- and right-wing political leaders

Spontaneous emotionally congruent facial responses (ECFR) to others’ emotional expressions can occur by simply observing others’ faces (i.e., smiling) or by reading emotion related words (i.e., to smile). The goal of the present study was to examine whether language describing political leaders’ emotions affects voters by inducing emotionally congruent facial reactions as a function of readers’ and politicians’ shared political orientation. Participants read sentences describing politicians’ emotional expressions, while their facial muscle activation was measured by means of electromyography (EMG). Results showed that reading sentences describing left and right-wing politicians “smiling” or “frowning” elicits ECFR for ingroup but not outgroup members. Remarkably, ECFR were sensitive to attitudes toward individual leaders beyond the ingroup vs. outgroup political divide. Through integrating behavioral and physiological methods we were able to consistently tap on a ‘favored political leader effect’ thus capturing political attitudes towards an individual politician at a given moment of time, at multiple levels (explicit responses and automatic ECFR) and across political party membership lines. Our findings highlight the role of verbal behavior of politicians in affecting voters’ facial expressions with important implications for social judgment and behavioral outcomes.

Event-related potentials of automatic imitation are modulated by ethnicity during stimulus processing, but not during motor execution

This study investigated neural processes underlying automatic imitation and its modulation by ethnically diverse hand stimuli (Black, White) using event-related brain potentials (ERPs). Automatic imitation relies on motor stimulus-response compatibility (SRC), i.e., response conflict caused by motoric (in)congruency between task-irrelevant hand stimuli and the required response. Our novel task aimed to separate two distinct neuro-cognitive processing stages of automatic imitation and its modulation by ethnicity: the stage of stimulus processing (i.e. perception), comprising presentation of stimulus ethnicity and SRC, and the stage of response execution (i.e. action). Effects of ethnicity were observed in ERPs of different stages of stimulus processing - during presentation of ethnicity (LPP) and SRC (N190, P3). ERPs at response execution, Pre-Motion Positivity (PMP) and Reafferent Potential (RAP), were only sensitive to congruency. The N190 results may index visual self-other distinction, while the neural timecourse of P3 and PMP variation could reflect a dynamical decision process linking perception to action, with motor initiation reflected in the PMP component. The PMP might further index motor-related self-other distinction regardless of ethnicity. Importantly, overt motor execution was not influenced by ethnically diverse stimuli, which suggests generalizability of the automatic imitation effect across ethnicities.

Mimicking emotions

Emotional mimicry refers to the tendency to mimic other's emotions in order to share minds. We present new evidence that supports our Contextual Model of Emotional Mimicry, showing that emotional mimicry serves affiliative goals that vary across social contexts. This also implies the opposite, namely that we (unconsciously) refrain from mimicking others' emotions if we want to keep emotional distance. Facial mimicry of emotions is further suggested to be a largely top-down process, based on goals and representations, rather than on mere watching others' facial movements.

Age invariance in rapid facial affective reactions to emotionally valenced stimuli

It has been suggested that an age-related positivity effect may only occur in the context of explicit information processing, but it is unclear whether this bias extends to the processing of rapid facial reactions. In addition, most studies that have looked for evidence of age-related implicit positivity have used attentional (as opposed to sensory) unawareness paradigms, or used broad-based indicators of attentional awareness that do not speak to the nature of the affective response. In the present study, younger and older adults were therefore asked to view non-facial images presented supraliminally (i.e., consciously) as well as outside of sensory awareness (i.e., subliminally) while their facial reactions were indexed using electromyography. The results indicated that both younger and older adults exhibited rapid facial reactions congruent with the emotional valence of non-facial images in both supraliminal and subliminal conditions. Relative to young, older adults did not respond with greater zygomaticus (cheek) activity to positive stimuli or reduced corrugator (brow) activity to negative stimuli in either condition. These data show that rapid facial reactions to emotional stimuli are intact in late adulthood, even in response to stimuli that activate more automatic and implicit forms of emotion processing. However, there is no evidence for any age-related positivity bias in these behavioral responses.

The Influence of Facial Signals on the Automatic Imitation of Hand Actions

Imitation and facial signals are fundamental social cues that guide interactions with others, but little is known regarding the relationship between these behaviors. It is clear that during expression detection, we imitate observed expressions by engaging similar facial muscles. It is proposed that a cognitive system, which matches observed and performed actions, controls imitation and contributes to emotion understanding. However, there is little known regarding the consequences of recognizing affective states for other forms of imitation, which are not inherently tied to the observed emotion. The current study investigated the hypothesis that facial cue valence would modulate automatic imitation of hand actions. To test this hypothesis, we paired different types of facial cue with an automatic imitation task. Experiments 1 and 2 demonstrated that a smile prompted greater automatic imitation than angry and neutral expressions. Additionally, a meta-analysis of this and previous studies suggests that both happy and angry expressions increase imitation compared to neutral expressions. By contrast, Experiments 3 and 4 demonstrated that invariant facial cues, which signal trait-levels of agreeableness, had no impact on imitation. Despite readily identifying trait-based facial signals, levels of agreeableness did not differentially modulate automatic imitation. Further, a Bayesian analysis showed that the null effect was between 2 and 5 times more likely than the experimental effect. Therefore, we show that imitation systems are more sensitive to prosocial facial signals that indicate “in the moment” states than enduring traits. These data support the view that a smile primes multiple forms of imitation including the copying actions that are not inherently affective. The influence of expression detection on wider forms of imitation may contribute to facilitating interactions between individuals, such as building rapport and affiliation.