The causes and consequences of yawning in animal groups

Inertia and Rapid Divergence in the Evolution of Yawning: A Comparison Between Two Closely Related but Socially Different Monkeys

Complex communication systems appear to evolve alongside social complexity. Comparing closely related species with similar social structures but distinct sociobiology offers valuable insights into the evolution of communicative variability. Here, we explore yawning (morphology, sensory modalities, contexts, contagious effect), a highly conserved behavioral trait, in two zoo-housed groups of geladas (Theropithecus gelada, nsubjects = 67, nyawns = 1422) and hamadryas baboons (Papio hamadryas, nsubjects = 28, nyawns = 602). The species are optimal candidates as they both form multilevel groups but differ in intra-group dynamics, cohesion, and cross-sex bonding. Although both species displayed distinct yawn morphologies, hamadryas yawned less frequently than geladas, mainly in non-social contexts and without vocalization. In contrast, geladas yawned more often during affiliative interactions, highlighting a more social dimension to their yawns. When focusing on silent yawns, hamadryas showed a male-biased yawning frequency, whereas geladas exhibited similar rates between sexes, suggesting a more prominent female role in their yawning patterns. We found that yawning is contagious not only in geladas, as previously known, but also in hamadryas baboons. However, geladas were more responsive to others' yawns, possibly due to their greater communicative complexity or to the need to maintain cohesion in larger groups. In geladas, both sexes exhibited similar levels of yawn contagion, whereas in hamadryas it was predominantly male-driven, reflecting the central role of males in hamadryas social dynamics. Our study suggests both evolutionary inertia and divergence in Papionine yawning evolution. The findings confirm the derived nature of gelada yawn vocalizations and highlight the link between multimodal communication and social complexity. Moreover, geladas exhibit more nuanced, context-dependent yawning, likely shaped by their intricate sociobiology. In contrast, hamadryas display a more male-dominated yawning pattern, reflecting their distinct social dynamics. To fully understand the ecological significance of this ancient behavior, further cross-species research on yawning and its contagious effect in wild populations is essential.

Diving back two hundred million years: yawn contagion in fish

Yawning is a widespread and automatic behavior in vertebrates. Yawn contagion, responding with a yawn to others' yawns, helps synchronize motor activities, particularly in social animals, promoting coordination within groups. While primarily observed in social, endothermic species, yawn contagion remains unconfirmed in ectotherms. We discovered yawn contagion in zebrafish (Danio rerio). Using a deep learning model to distinguish yawning from breathing, we found that fish not only yawn but also "catch" yawns from others. The presence of yawn contagion in fish raises important evolutionary questions, particularly regarding its origin. According to evolutionary biology theories, on one hand, it could be a shared trait among vertebrates, with the secondary loss of this phenomenon in some taxa. On the other hand, it may be a result of convergent evolution, emerging independently in different evolutionary lineages as a response to the need for synchronization of motor actions within social groups.

Yawning in sync: implications for social cohesion in horses

The increasing interest in the study of spontaneous (SY) and contagious yawning (CY) was so far focused on several taxa, especially primates. Here, we focused on SY and CY in horses, a suitable species due to their complex social dynamics that has been largely overlooked in research on these phenomena. By analyzing videos of 48 horses on pasture, we identified 2 yawning morphologies: Covered (Y CT) and Uncovered Teeth (Y UCT). Using EquiFACS, we quantitatively demonstrated that Y CT and Y UCT differ in terms of muscle recruitment. Moreover, we provide the first evidence for the presence of CY by comparing 2 different conditions: chewing-yawn-chewing versus chewing-chewing-chewing. Supporting the Social Modulation hypothesis, in our mares, CY was more prominent among subjects sharing good relationships. Moreover, subjects responded more rapidly to kin compared with non-kin and kin frequently grooming each other responded even more rapidly to each other yawns. The high familiar yawn sensitivity can provide selective advantages increasing behavioral synchronization and group cohesion.

Is it a Match? Yawn Contagion and Smile Mimicry in Toddlers

Automatic behavioral matching includes Rapid Facial Mimicry (RFM) and Yawn Contagion (YC) that occur when the facial expression of an individual acts as a 'mirror social releaser' and induces the same facial expression in the observer (within 1 s for RFM, and minutes for YC). Motor replication has been linked to coordination and emotional contagion, a basic form of empathy. We investigated the presence and modulating factors of Rapid Smile Mimicry (RSM) and YC in infants/toddlers from 10 to 36 months at the nursery 'Melis' (Turin, Italy). In February-May 2022, we gathered audio and/or video of all occurrences data on affiliative behaviors, smiling during play, and yawning during everyday activities. Both RSM and YC were present, as toddlers were most likely to smile (within 1 s) or yawn (within three-min) after perceiving a smile/yawn from another toddler. Sex, age, and parents' country of origin did not influence RSM and YC occurrence, probably because gonadal maturation was long to come, the age range was skewed towards the early developmental phase, and toddlers had been in the same social group for months. RSM and YC showed social modulation, thus possibly implying more than just motor resonance. Both phenomena were inversely related to affiliation levels (a social bond proxy). Because literature reports that in adults RSM and YC may increase with familiarity, our reversed result suggests that in certain toddler cohorts the same phenomena may help increase socio-emotional coordination and that the function of motoric resonance may be experience- and context-dependent.

Yawn Contagion and Modality-Matching in the Female-Bonded Society of Geladas (Theropithecus gelada)

Behavioral contagion is widespread in primates, with yawn contagion (YC) being a well-known example. Often associated with ingroup dynamics and synchronization, the possible functions and evolutionary pathways of YC remain subjects of active debate. Among nonhuman animals, geladas (Theropithecus gelada) are the only species known to occasionally emit a distinct vocalization while yawning. Yet, the role of different sensory modalities in YC remains poorly understood. Due to their social and communicative complexity, geladas serve as an excellent model for investigating the effects of multimodality and social factors on behavioral contagion. Here we studied a large zoo-housed colony of geladas (103 subjects, 1422 yawns) and confirm the previous evidence for visual and auditory YC. Hearing, seeing, or hearing and seeing yawns significantly triggered contagious yawning at comparable levels. Additionally, we found no evidence of laterality influencing responses based on the side of detection. While the social bond, measured via grooming, between the trigger and receiver did not correlate with YC, a consistent sex effect emerged. Females responded more frequently to female than to male yawns and were more likely to match modality (i.e., vocalized vs. nonvocalized) and mirror morphology of other females' yawns. Effective female-female communication and affiliation are crucial for maintaining cohesion and fostering strong intra-unit relationships among geladas. Our results underscore the importance of different sensory components in the distribution of YC, particularly for species living in complex social systems. These findings raise further questions about the functional and emotional significance of yawning and potential inter-sexual differences, suggesting that the phenomenon is more complex than previously thought.

First predict, then bond: Rethinking the function of mimicry from prediction to affiliation in human and non-human animals

Automatic mimicry, where social animals mimic the emotional expressions of others, is a well-documented phenomenon. While research has extensively examined how being mimicked influences our perception of others, the fundamental question of why we mimic remains largely unexplored. Previous theories often link mimicry with an affiliative social goal. While we agree that mimicry can increase survival chances by enhancing group cohesion, we argue for a more primitive adaptive value that may operate independently of social bonding. By reviewing existing literature, we propose that mimicry serves as a mechanism to predict other individuals, and consequently, the environment, enhancing survival of the individual. We posit a shift towards understanding mimicry as a mechanism that minimizes prediction error, empowering individuals to navigate their surroundings more effectively. Embracing mimicry as a tool for self-preservation and environmental prediction opens new avenues for interdisciplinary research in comparative psychology and behavioral ecology.

The sociality of sleep in animal groups

Group-living animals sleep together, yet most research treats sleep as an individual process. Here, we argue that social interactions during the sleep period contribute in important, but largely overlooked, ways to animal groups' social dynamics, while patterns of social interaction and the structure of social connections within animal groups play important, but poorly understood, roles in shaping sleep behavior. Leveraging field-appropriate methods, such as direct and video-based observation, and increasingly common on-animal motion sensors (e.g., accelerometers), behavioral indicators can be tracked to measure sleep in multiple individuals in a group of animals simultaneously. Sleep proximity networks and sleep timing networks can then be used to investigate the collective dynamics of sleep in wild group-living animals.

Beware! Different methods lead to divergent results on yawn contagion modulation in bonobos

Contagious yawning (CY)-linked to physiological synchronization and possibly emotional contagion-occurs when one individual's yawn induces yawning in others. CY was investigated over different time windows (minutes from the triggering stimulus) via naturalistic or experimental studies (using real and video yawns, respectively) with contrasting results, especially in bonobos. We verified whether in bonobos result divergences may derive from different methods. We gathered yawning data on 13 bonobos at Twycross Zoo (UK) via a naturalistic (all-occurrences observations) and experimental approach (by showing yawn/control video stimuli). Based on literature, we used 1- and 3-min windows to detect CY. Due to fission-fusion management, individuals could form permanent or non-permanent associations (more/less familiar subjects under naturalistic setting). Video yawn stimuli may come from group mates/stranger models (more/less familiar subjects under the experimental setting). Stimulus type and time window affected CY modulating factors but not CY detection. Familiarity and age effect on CY showed opposite trends in 3-min trials and 1-min observations. CY was highest in oldest, non-permanently (rather than permanently) associated subjects in the naturalistic setting, but in the youngest subjects and with ingroup (rather than outgroup) models in trials. The age effect differences on CY might be due to decontextualized yawns and immature subject curiosity toward videos. The reversed familiarity effect suggests CY's context-dependent function in promoting social synchronization with socially distant group mates, as failing to coordinate as a group may lead to social disruption. Complementary methods are needed to fully understand motor replication phenomena.

Selective and prolonged attention to emotional scenes in humans and bonobos

Perceiving emotions in others is at the foundation of higher-order social cognition. The importance of emotions is evidenced by the fact that they receive prioritized attention at early stages of processing the environment in humans and some other primates. Nevertheless, we do not fully understand how emotion modulates attention over longer durations in primates, particularly in great apes. Bonobos, one of our closest relatives, stand out in emotion processing and regulation among great apes. This makes them an interesting comparison species and a valuable model for studying the evolution of emotion perception in hominids. We investigated how bonobos and humans spontaneously attend to emotionally valent scenes in a preferential looking task using eye-tracking. With Bayesian mixed modelling, we found that bonobos and humans generally looked longer at emotional scenes, mainly of conspecifics. Moreover, while bonobos did not have a bias toward emotional human scenes, humans sustained their attention toward bonobos playing, grooming and having sex. Furthermore, when exploring an immediate bias for emotions, humans showed a bias toward affiliative human scenes, and bonobos showed a bias away from bonobos-in-distress scenes. These findings suggest that emotions modulate attention at early and later attentional stages in bonobos, similar to humans.

More than a simple fixed action pattern: Yawning in drills

In the last decade, increasing attention has been devoted to exploring some aspects of yawning in non-human animals. With their chin red mark, bony paranasal swellings, male large brains and long canines, drills (Mandrillus leucophaeus) offer a robust model for testing hypotheses on the phenomenon. We identified two yawn variants (covered, YCT and uncovered teeth, YUCT) which differ in terms of recruitment of muscular action units (AUs). We tested the effects of several variables (sex, dominance rank, context) on the duration of the yawn and the probability of YCT or YUCT occurrence. We found that males performed longer and more YUCT than females. These findings support the Brain Cooling Hypothesis suggesting that those species showing large brains tend to display larger and longer yawns. We also tested the State Changing Hypothesis predicting the presence of a temporal association of yawning and ongoing behavioral transitions. A sequential analysis revealed that after 30 s following a yawn, drills were significantly more likely to change their behavioral state. Through the observation of yawning, conspecifics might gain knowledge of impending state changes. Seeing other's yawns increased the probability of a similar response in the observers, thus suggesting the presence of yawn contagion in drills. Although the dataset needs to be expanded, our findings indicate that yawning is variable in drills, it can be associated with subjects' state changes, and the imminent shifts can be perceived/processed by conspecifics.

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.

Social Cognitive Correlates of Contagious Yawning and Smiling

It has been theorized that the contagion of behaviors may be related to social cognitive abilities, but empirical findings are inconsistent. We recorded young adults' behavioral expression of contagious yawning and contagious smiling to video stimuli and employed a multi-method assessment of sociocognitive abilities including self-reported internal experience of emotional contagion, self-reported trait empathy, accuracy on a theory of mind task, and observed helping behavior. Results revealed that contagious yawners reported increases in tiredness from pre- to post-video stimuli exposure, providing support for the internal experience of emotional contagion, and were more likely to provide help to the experimenter relative to non-contagious yawners. Contagious smilers showed stably high levels of self-reported happiness from pre- to post-video exposure, were more likely to provide help to the experimenter, and had increased accuracy on a theory of mind task relative to non-contagious smilers. There were no differences in self-reported trait empathy for contagious versus non-contagious yawners or smilers. Contagious yawning may be related to some basic (i.e., emotional contagion) and advanced (i.e., helping behavior) sociocognitive processes, whereas contagious smiling is related to some advanced sociocognitive processes (i.e., theory of mind and helping behavior).

The Role of Empathic Concern and Gender on Interspecific Contagious Yawning in Humans

Interspecific contagious yawning (CY), whereby yawns from one species trigger yawning in different species, has now been reported across various taxa. This response to human yawning appears common among animals in captivity and has been interpreted as an empathic response towards human handlers/caregivers. A recent study found that humans also display interspecific CY, though this response was not modulated by proxies of empathic processing (i.e., phylogenetic relatedness or social closeness to the animals). Here, we explored this relationship more explicitly by assessing how interspecific CY to yawns from common household pets relates to self-reported empathic concern. Participants (N = 103) completed a survey measuring empathic concern and then reported on their yawning behavior following exposure to a control condition or yawning images either from domesticated cats or domesticated dogs. The results provide further evidence for interspecific CY in humans, but empathic concern was negatively predictive of this response. There was also no sex difference in interspecific CY, though when comparing the sexes across CY conditions, women reported a higher frequency of yawning in response to dog yawns, and men reported a higher frequency of yawning in response to cat yawns. Overall, these findings do not support a strong connection between interspecific CY and empathy or emotional contagion.

How video calls affect mimicry and trust during interactions

Many social species, humans included, mimic emotional expressions, with important consequences for social bonding. Although humans increasingly interact via video calls, little is known about the effect of these online interactions on the mimicry of scratching and yawning, and their linkage with trust. The current study investigated whether mimicry and trust are affected by these new communication media. Using participant-confederate dyads (n = 27), we tested the mimicry of four behaviours across three different conditions: watching a pre-recorded video, online video call, and face-to-face. We measured mimicry of target behaviours frequently observed in emotional situations, yawn and scratch and control behaviours, lip-bite and face-touch. In addition, trust in the confederate was assessed via a trust game. Our study revealed that (i) mimicry and trust did not differ between face-to-face and video calls, but were significantly lower in the pre-recorded condition; and (ii) target behaviours were significantly more mimicked than the control behaviours. This negative relationship can possibly be explained by the negative connotation usually associated with the behaviours included in this study. Overall, this study showed that video calls might provide enough interaction cues for mimicry to occur in our student population and during interactions between strangers. This article is part of a discussion meeting issue 'Face2face: advancing the science of social interaction'.

Contagious yawning in African painted dogs

Contagious yawning (CY), which is yawning elicited by sensing another yawning, has been observed only in social species and is considered linked to high sociality. Although this idea-the social communication hypothesis-is supported by previous studies, investigating the occurrence of CY in various species remains necessary. We investigated the occurrence of CY in one of the most social canine species, the African painted dog (Lycaon pictus). We recorded 1387 yawn events from five pairs (10 individuals) in captivity. Temporal analysis showed that subsequent yawns occurred frequently within 15 s or 30 s after spontaneous yawns (SYs). SYs that were detectable by another individual (i.e., visible to the other individual or performed in close proximity) were more likely to elicit subsequent yawns by the other individual. However, the influence of contextual factors on CY differed according to the time window, implying that a conservative time window should be used to reduce overcounting of CY and misattribution of its determinants. The proportion of CY was positively related to time spent in physical proximity to another, a proxy for a social bond. Overall, our results provide the first evidence of CY in African painted dogs and further support the notion that such behavior is prevalent among social animals. They also strongly imply that an appropriate time window should be used to define yawn contagion.

The Effect of Stabling Routines on Potential Behavioural Indicators of Affective State in Horses and Their Use in Assessing Quality of Life

Increasing interest in equine welfare has emphasised the need for objective and reliable behavioural indicators of horses’ affective state. However, research has yielded mixed results regarding behaviours suited for industry use largely because they are subject to anthropomorphic interpretation. Stabling is commonly used to manage domesticated horses despite research indicating that it can negatively impact horse welfare, but its effect on their affective state is yet to be quantified. Ten adult horses (11.8 ± 4.4 years) were observed either on a day- (DS) or night-stabling (NS) schedule over two consecutive 24 h periods. NS horses were kept confined for significantly longer (13.60 ± 0.04 h) than DS horses (7.73 ± 0.07; t7 = 5.70; p = 0.0004). Eight behaviours occurred significantly more often during NS than DS: forward ears (t7 = 3.32; p = 0.001), neutral ears (t7 = 3.47; p = 0.001), stepping forward (t7 = 2.62; p = 0.001), stepping laterally (t7 = 2.39; p = 0.001), sternal recumbency (t7 = 2.64; p = 0.001), yawning (t7 = 2.69; p = 0.001), non-nutritive chewing (t7 = 2.49; p = 0.001), and closing eyes (t7 = 2.71; p = 0.001). These behaviours may be candidates for indicators that can be used to determine the affective state in horses and subsequently be used to assess equine quality of life and to optimise individual horse welfare.

Yawning informs behavioural state changing in wild spotted hyaenas

Abstract

Yawning is a complex behaviour linked to several physiological (e.g. drowsiness, arousal, thermoregulation) and social phenomena (e.g. yawn contagion). Being yawning an evolutionary well-conserved, fixed action pattern widespread in vertebrates, it is a valuable candidate to test hypotheses on its potential functions across the different taxa. The spotted hyaena (Crocuta crocuta), the most social and cooperative species of the Hyaenidae family, is a good model to test hypotheses on yawning correlates and significances. Through an accurate sequential analysis performed on a group of wild hyaenas, we found that yawning mainly occurred during an imminent behavioural state changing in both juveniles and adults and that seeing others’ yawn elicited a mirror response in the receiver, thus demonstrating that yawn contagion is present in this species. These results taken together suggest that yawning is linked to a behavioural state change of the yawner and that such change is caught by the observers that engage in a motor resonance phenomenon, yawn contagion, possibly effective in anticipating yawners’ motor actions. Although additional data are necessary to verify whether yawn contagion translates into subsequent motor convergence and alignment, our data suggest that both spontaneous and contagious yawning can be fundamental building blocks on the basis of animal synchronisation in highly social and cooperative species.

Significant statement

Yawning is pervasive in many animal species, including humans. It is considered as a polyfunctional cue that has a role in regulating social interactions. While several studies focussed on yawning functions in primates, a little amount of effort was devoted to exploring this behaviour in social carnivores. We monitored a group of wild spotted hyaenas (Crocuta crocuta), which is one of the most cooperative carnivore species. In both immature and adult subjects, we found that a subject frequently changed its behavioural state after spontaneously yawning and that seeing others’ yawn elicited a mirror response in the observer. Although additional data are necessary to verify whether yawn contagion translates into subsequent motor convergence and alignment, our data suggest that both spontaneous and contagious yawning can be fundamental building blocks on the basis of animal synchronisation in highly social and cooperative species.

Mimicry eases prediction and thereby smoothens social interactions

In their "social contextual view" of emotional mimicry, authors Hess and Fischer (2022) put forward emotional mimicry as a social regulator, considering it a social act, bound to certain affiliative contexts or goals. In this commentary, we argue that the core function of mimicry is to ease predicting conspecifics' behaviours and the environment, and that as a consequence, this often smoothens social interactions. Accordingly, we make three main points. First, we argue that there is no good reason to believe that the mimicry of negative expressions is fundamentally different than the mimicry of positive or ambiguous or autonomic expressions. Second, we give examples of empirical evidence that mimicry is not always a social act. Third, we show that mimicry has primary benefits for the mimicker. As such, we will briefly summarise and elaborate on the relevant findings in these respects, and propose a comparative, multi-method and ecologically valid approach which can explain the multifaceted character of the phenomenon.

Interspecific Contagious Yawning in Humans

Simple Summary

Contagious yawning has been observed in humans and a growing number of social vertebrates. While the majority of studies on yawn contagion have documented this phenomenon amongst conspecifics, there is also evidence for interspecific contagious yawning among non-human animals in captivity. This study was the first to formally investigate whether humans also yawn in response to yawns from different species. In particular, participants were exposed to yawning stimuli either from (1) fish, (2) amphibians, (3) reptiles, (4) birds, (5) non-primate mammals, (6) apes, or (7) domesticated cats and dogs. Overall, the results provide strong support for interspecific contagious yawning in humans, with 69% reporting yawn contagion during testing. This response was not altered by phylogenetic proximity or domestication, suggesting that the mechanisms governing yawn contagion are generalized, and can be triggered by varied representations of yawning across diverse taxa.

Abstract

Contagious yawning, or the reflexive tendency to yawn following the detection of yawning in others, is well-documented among humans and a growing number of social vertebrates. While the most common form of yawn contagion occurs between conspecifics, some non-human animals in captivity have been reported to yawn in response to yawns from human handlers/caregivers. The current research sought to provide the first formal investigation of whether people yawn contagiously in response to yawns from non-human animals. In addition, this study aimed to test whether this response was modulated by phylogenetic relatedness and domestication/social closeness. A total of 296 participants from Amazon Mechanical Turk self-reported on their yawning behavior following exposure to a (1) control (non-yawning) condition or a compilation of yawning stimuli either from (2) fish, (3) amphibians, (4) reptiles, (5) birds, (6) non-primate mammals, (7) apes, or (8) domesticated cats and dogs. The results provide strong support for interspecific yawn contagion. However, neither the propensity to yawn (binary) nor total yawn frequency varied significantly across interspecific conditions. Overall, these findings suggest that the mechanisms governing yawn contagion can be activated by varied forms of yawning stimuli, including those from distantly related and unfamiliar species.

Familiarity modulates both intra- and interspecific yawn contagion in red-capped mangabeys

Yawn contagion (YC) is, compared to spontaneous yawning, an evolutionary recent phenomenon probably linked to behavioral synchronization in highly social species that is more likely when it involves familiar subjects. Here, we investigate for the first time in monkeys which factors modulate intra- and interspecific YC. Through an experimental approach, we exposed 17 red-capped mangabeys to video stimuli (Yawn vs Control) depicting familiar/unfamiliar red-capped mangabeys and humans, and unfamiliar hamadryas. We found that mangabeys yawned more often in response to Yawn than Control videos independently from the species depicted, demonstrating both intra- and interspecific YC in the tested species. Moreover, both mangabey and human familiar yawning stimuli evoked a stronger yawning response in the subjects compared to the unfamiliar counterparts. Neither the amount of time spent looking frontally at the screen (probability of stimulus perception) nor the levels of self-directed behaviors (a proxy of anxiety) accounted for the results. In conclusion, we provide the first evidence that in non-human primate familiarity modulates both intra- and inter-specific YC. Stimuli emitted by familiar faces somehow ease the mechanisms underlying YC, and this modulation can also apply to heterospecific subjects when previous shared experiences provide the prerequisites for the development of social bonds.

No Evidence for Contagious Yawning in Juvenile Ravens (Corvus corax): An Observational Study

The overt and reflexive matching of behaviors among conspecifics has been observed in a growing number of social vertebrates, including avian species. In general, behavioral contagion-such as the spread of yawning-may serve important functions in group synchronization and vigilance behavior. Here, we performed an exploratory study to investigate yawn contagion among 10 captive juvenile ravens (Corvus corax), across two groups. Using observational methods, we also examined the contagiousness of three other distinct behaviors: stretching, scratching, and shaking. A total of 44 20 min observations were made across both groups, including 28 in the morning and 16 in the afternoon. The time and occurrence of all the behaviors from each bird were coded, and the temporal pattern of each behavior across both groups was then analyzed to assess the degree of social contagion. Overall, we found no evidence for contagious yawning, stretching, scratching, or shaking. However, yawns were relatively infrequent per observation (0.052 ± 0.076 yawns/bird) and thus experimental methods should be used to support this finding.