Integrating Tinbergen's inquiries: Mimicry and play in humans and other social mammals

Behavioural Synchronisation between Dogs and Humans: Unveiling Interspecific Motor Resonance?

Dogs' behavioural synchronisation with humans is of growing scientific interest. However, studies lack a comprehensive exploration of the neurocognitive foundations of this social cognitive ability. Drawing parallels from the mechanisms underlying behavioural synchronisation in humans, specifically motor resonance and the recruitment of mirror neurons, we hypothesise that dogs' behavioural synchronisation with humans is underpinned by a similar mechanism, namely interspecific motor resonance. Based on a literature review, we argue that dogs possess the prerequisites for motor resonance, and we suggest that interspecific behavioural synchronisation relies on the activation of both human and canine mirror neurons. Furthermore, interspecific behavioural studies highlight certain characteristics of motor resonance, including motor contagion and its social modulators. While these findings strongly suggest the potential existence of interspecific motor resonance, direct proof remains to be established. Our analysis thus paves the way for future research to confirm the existence of interspecific motor resonance as the neurocognitive foundation for interspecific behavioural synchronisation. Unravelling the neurocognitive mechanisms underlying this behavioural adjustment holds profound implications for understanding the evolutionary dynamics of dogs alongside humans and improving the day-to-day management of dog-human interactions.

Behavioural synchronization and social referencing of dogs and humans: walking in dyad vs in group

Recent studies have demonstrated that dogs synchronize their locomotor behaviour with that of their owners. The present study aims to improve our understanding of the sensorimotor processes underlying interspecific behavioural synchronization by testing the influence of the number of humans on dogs' behavioural synchronization. We used Global Positioning System (GPS) devices in an outdoor environment to measure dogs' behavioural synchronization to humans during a locomotor activity involving three speeds (static, slow walking and fast walking). For half of the dogs, only their owner was walking, while for the other half, the owner walked with two familiar people. We also tested the effect of dog breeds by involving 30 shepherd dogs and 30 molossoids. Our results showed that dogs exhibited the same level of behavioural synchronization with their owner if alone or if surrounded by two familiar people. Though the presence of a group of humans did not strengthen the dogs' locomotor synchronization, it did produce another effect: dogs gazed at their owners more frequently in the presence of a group compared to their owner alone. This result suggests the same level of locomotor social entrainment but a difference in social referencing depending on the number of humans.

Collective Rhythm as an Emergent Property During Human Social Coordination

The literature on social interactions has shown that participants coordinate not only at the behavioral but also at the physiological and neural levels, and that this coordination gives a temporal structure to the individual and social dynamics. However, it has not been fully explored whether such temporal patterns emerge during interpersonal coordination beyond dyads, whether this phenomenon arises from complex cognitive mechanisms or from relatively simple rules of behavior, or which are the sociocultural processes that underlie this phenomenon. We review the evidence for the existence of group-level rhythmic patterns that result from social interactions and argue that the complexity of group dynamics can lead to temporal regularities that cannot be predicted from the individual periodicities: an emergent collective rhythm. Moreover, we use this interpretation of the literature to discuss how taking into account the sociocultural niche in which individuals develop can help explain the seemingly divergent results that have been reported on the social influences and consequences of interpersonal coordination. We make recommendations on further research to test these arguments and their relationship to the feeling of belonging and assimilation experienced during group dynamics.

Playing together, laughing together: rapid facial mimicry and social sensitivity in lowland gorillas

In nonhuman animals, the phenomenon of rapid facial mimicry (RFM)—the automatic, involuntary, and rapid (<1 s) replication of others’ facial expressions—has been mainly investigated in the playful domain. In immature lowland gorillas Gorilla gorilla gorilla both play face (PF) and full PF (FPF) are rapidly mimicked between the players. This makes the species suitable to test hypotheses on the factors influencing RFM during play. The observations on 3 captive groups of lowland gorillas (N = 27) revealed that contrary to expectations, the closeness of social bond negatively influenced the occurrence of RFM but it did not affect either RFM latency or its overlapping index (OVERLAP). RFM was affected by the degree of symmetry of play fighting: the more balanced the session, the higher the occurrence of RFM. Players of the same sex class responded faster than players of different sex. These findings suggest that RFM may help synchronizing behaviors of playmates matching in size (same-sex) and promote symmetric playful interactions. “Laughing together” (measured by the RFM OVERLAP) lasted longer when the responder perfectly mirrored the partner expression (PF→PF; FPF→FPF). If PF and FPF convey information on the different play roughness degree, through “laughing together” the players could coordinate their actions and share positive moods and playful intensity. If the perfect congruency in the motor resonance, also known as social sensitivity, can foster a possible emotional dialogue between gorillas remains to be investigated.

Mirror replication of sexual facial expressions increases the success of sexual contacts in bonobos

Rapid Facial Mimicry (RFM), one of the possible predictors of emotional contagion, is defined as the rapid, involuntary and automatic replication of a facial expression. Up to now, RFM has been demonstrated in nonhuman animals exclusively during play. Since in bonobos, as in humans, socio-sexuality is a powerful tool for assessing/strengthening inter-individual relationships, we investigated RFM in this domain. Bonobos displayed silent bared-teeth (sbt, the most common facial expression during sexual contacts) more frequently after the detection of an sbt emitted by the trigger than in the no-detection condition. This is the first demonstration of the presence of RFM during sex. The occurrence of RFM was positively affected by the sex of the partners with female homo-sexual contacts being punctuated by a higher presence of RFM. At an immediate level, RFM increased the duration of homo- and hetero-sexual contacts. This finding suggests that RFM can increase individuals’ potential fitness benefits. By prolonging their sexual contacts, females can strengthen their social relationships thus increasing the probability to obtain priority over resources (RFM indirect fitness benefits). Via longer copulations, males can increase the probability to make females pregnant (RFM direct fitness benefits). In conclusion, in bonobos the access to the partner’s face during sexual contacts (face-to-face, proximate factor) and the role of socio-sexuality in increasing the individual direct and indirect fitness (ultimate factor) could have favoured the evolution of specific sexual facial expressions and their rapid mirror replication. Our findings on bonobos expand the role of RFM well beyond the animal play domain thus opening new scenarios for future comparative studies exploring the evolution of socio-sexuality in humans.

Intraspecific Motor and Emotional Alignment in Dogs and Wolves: The Basic Building Blocks of Dog-Human Affective Connectedness

Involuntary synchronization occurs when individuals perform the same motor action patterns during a very short time lapse. This phenomenon serves an important adaptive value for animals permitting them to socially align with group fellows thus increasing integration and fitness benefits. Rapid mimicry (RM) and yawn contagion (YC) are two behavioral processes intermingled in the animal synchronization domain. Several studies demonstrated that RM and YC are socially modulated being more frequently performed by individuals sharing close relationships. This evidence highlights the relation between RM/YC and emotional contagion that is the capacity of two or more individuals to share the same affective state. In this review, we try to delineate a possible developmental trajectory of emotional sharing phenomena by using, as a model species, the domestic dog (Canis lupus familiaris), a valid example of empathic predisposition towards individuals belonging both to the same and the different species. We contrast available findings on RM and YC in dog-dog and dog-human dyads with those in wolf-wolf dyads, in order to investigate if the ability to emotionally engage with conspecifics (wolf-wolf and dog-dog) is evolutionary rooted in canids and if provides the basis for the development of inter-specific emotional sharing (dog-human).

Sharing playful mood: rapid facial mimicry in Suricata suricatta

One of the most productive behavioural domains to study visual communication in mammals is social play. The ability to manage play-fighting interactions can favour the development of communicative modules and their correct decoding. Due to their high levels of social cohesion and cooperation, slender-tailed meerkats (Suricata suricatta) are a very good model to test some hypotheses on the role of facial communication in synchronizing playful motor actions. We found that the relaxed open mouth (ROM), a playful facial expression conveying a positive mood in several social mammals, is also present in meerkats. ROM was mainly perceived during dyadic playful sessions compared to polyadic ones. We also found that meerkats mimic in a very rapid and automatic way the ROM emitted by playmates (Rapid Facial Mimicry, RFM). RFM was positively correlated with the relationship quality shared by subjects, thus suggesting that the mimicry phenomenon is socially modulated. Moreover, more than the mere presence of isolated ROMs, the presence of at RFM prolonged the duration of the play session. Through RFM animals can share the emotional mood, they are experiencing and this appears to be particularly adaptive in those species, whose relationships are not inhibited by rank rules and when animals build and maintain their bonds through social affiliation. The meerkat society is cohesive and cooperative. Such features could have, therefore, favoured the evolution of facial mimicry, a phenomenon linked to emotional contagion, one of the most basic forms of empathy.

Playing it cool: Characterizing social play, bout termination, and candidate play signals of juvenile and infant Tibetan macaques (Macaca thibetana)

Play behaviors and signals during playful interactions with juvenile conspecifics are important for both the social and cognitive development of young animals. The social organization of a species can also influence juvenile social play. We examined the relationships among play behaviors, candidate play signals, and play bout termination in Tibetan macaques (Macaca thibetana) during juvenile and infant social play to characterize the species play style. As Tibetan macaques are despotic and live in groups with strict linear dominance hierarchies and infrequent reconciliation, we predicted that play would be at risk of misinterpretation by both the individuals engaged in the play bout and by those watching, possibly leading to injury of the players. Animals living in such societies might need to frequently and clearly signal playful intent to play partners and other group members to avoid aggressive outcomes. We gathered video data on 21 individually-identified juvenile and infant macaques (one month to five years of age) from the Valley of the Wild Monkeys, Mt. Huangshan, China. We used all-occurrence sampling to record play behaviors and candidate play signals based on an ethogram. We predicted that play groups would use multiple candidate play signals in a variety of contexts and in association with the number of audience members in proximity to the players and play bout length. In the 283 playful interactions we scored, juvenile and infant macaques used multiple body and facial candidate play signals. Our data showed that juvenile and infant Tibetan macaques use a versatile repertoire of play behaviors and signals to sustain play.