Behavioral Contagion Research Articles

Novel automated method to assess group dynamics reveals deficits in behavioral contagion in rats with social deficits

Behavioral copying is a key process in group actions, but it is challenging for individuals with autism spectrum disorder (ASD). We investigated behavioral contagion, or instinctual replication of behaviors, in Krushinky-Molodkina (KM) rats (n = 16), a new potential rodent model for ASD, compared to control Wistar rats (n = 15). A randomly chosen healthy Wistar male (“demonstrator rat”) was introduced to the homecage of experimental rats (“observers”) 10–14 days before the experiments to become a member of the group. For the implementation of the behavioral contagion experiment, we used the IntelliCage system, where rats can live in a group of 5–6 rats and their water visits can be automatically scored. During the experiment, the demonstrator was taken out of IntelliCage for a pre-test water deprivation and then placed back for the behavioral contagion test. As a result, a drinking behavior of the water-deprived demonstrator rat prompted water-seeking and drinking behaviors in the whole group. Unlike the Wistar controls, KM observers showed fewer visits to the drinking bottles, particularly lacking inspection visits (i.e., visits without drinking). The control group, in contrast, exhibited a dynamic, cascade-like visiting of the water corners. The proportion of activated observers in KM rats was significantly lower, as compared to Wistar ones, and they did not mimic other observer rats. KM rats, therefore, displayed an attenuated pattern of behavioral contagion, highlighting social deficits in this strain. This study suggests that measuring group dynamics of behavioral contagion in an automated, non-invasive setup offers valuable insights into social behavior in rodents.

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.

Contagious yawning and scratching in captive lemurs

Behavioral contagion is thought to play a significant role in social synchronization and coordination across animal taxa. While there is extensive evidence of behavioral contagion in Haplorrhines (i.e. monkeys and apes), limited research exists in Strepsirrhines (i.e. lemurs). Here, we aimed to investigate the presence of contagious yawning and scratching in two captive groups of black-and-white ruffed lemurs (Varecia variegata) (N = 4) and red ruffed lemurs (Varecia rubra) (N = 4), and further test whether behavioral contagion is modulated by the model’s social integration in the group. We conducted all occurrence sampling to examine whether individuals observing a yawning or scratching event (i.e. trigger event) were more likely to yawn or scratch in the following 2 min, as compared to individuals who did not observe it. We ran generalized linear mixed models and found that the likelihood of yawning and scratching was higher for subjects observing the trigger event than for subjects who did not observe the event, although the model’s social integration had no modulating effect on the probability of showing behavioral contagion. Our findings represent the first evidence of behavioral contagion in this genus and contribute to shed light on the distribution and the possible adaptive function of this phenomenon in primates.

Social contagions in business resilience: Evidence from the U.S. restaurant industry in the COVID-19 pandemic

The unprecedented COVID-19 has led to the collapse of numerous businesses, notably within the tourism and hospitality sectors. Despite the burgeoning research on resilience, few studies have embraced a theoretical lens, particularly from a social network perspective. In addition, most extant resilience studies have not explicitly considered the geographic accessibility prerequisite inherent to tourism and hospitality products. In this study, leveraging the social contagion theory, we present a holistic research framework to investigate the influence of geographic and social proximities, two pivotal social contagion mechanisms, on business resilience. We also delve into moderating factors to discern the conditions under which contagion effects are amplified or attenuated. To validate our theoretical model, we select the restaurant industry as our research context, given its severe impact from COVID-19. Utilizing an extensive dataset from Yelp, encompassing ten U.S. cities varying in sizes and geolocations, our findings indicate that both geographic and social influences exert significant direct effects on resilience. Additionally, these effects exhibit considerable variations contingent upon product attributes, customer characteristics, and geographic factors. Theoretically, we are the first to substantiate the role of social contagion theory in examining resilience, enriching our understanding of the social network mechanism of behavioral contagion among customers during the COVID-19 pandemic. We also offer valuable practical implications for various stakeholders in supporting their management strategies and decision-making in developing effective plans and preparations, minimizing adverse impacts, and ensuring sustainability in the face of future disruptions.

Exploring the neuropsychological basis of behavioral contagion during learning about another agent's social preferences: Evidence from an ERP study.

Social contagion is a pervasive phenomenon and an important social influence that involves the rapid dissemination (propagation) of behaviors, attitudes, emotions, or ideas from one person to another, often without conscious reflection or rational thought. This phenomenon is closely related to conformity, by which a person changes his/her original ideas and attitude and imitates certain behavior of others. Although some behavioral research has been carried out on contagion and conformity, there is very little neuropsychological understanding of these phenomena. Existing research on social influence and conformity has predominantly focused on tasks like mental rotation or rating tasks involving facial expressions, with fewer studies exploring risk preferences and temporal discounting. However, there is a notable gap in the literature when it comes to examining social influence and conformity using other‑regarding preference models derived from heterodox economics. To address this research gap, the present study investigates the neuropsychological underpinnings of social contagion by utilizing event‑related potentials (ERPs) recorded while subjects engage in mini‑dictator games. The behavioral analysis revealed that contagion had an impact on the participants' preferences, leading to a change in their choices. We observed a P300 component in the midline and right posterior during the time window of 200‑350 ms after stimulus onset, which showed a significant increase in mean amplitude when participants observed others' behavior, compared to when they made decisions based on their own preferences. Moreover, the lack of late positive potential in the time window of 500‑650 ms suggests that the presence of P300 may indicate difficulty in making decisions. In summary, by analyzing both behavioral and ERP data, this study may provide a more comprehensive understanding of the cognitive and neural processes that drive conformity and contagion behavior. Our analysis has the potential to inform policymakers in developing effective interventions for promoting positive social behaviors and reducing negative ones.

The behavioral contagion effect of tourists’ risk decision-making

This study investigated the contagion effect of other tourists' risk-seeking behavior on tourists' risk decision-making. It further examined the mediation of two contrasting motivational systems (approach-avoidance), and the moderation of destination management deterrence. Four experiments were conducted focusing on the risk decision-making of tourists in the context of undeveloped natural areas and tidal-bore watching settings. Independent samples t-tests, regression, and multivariate analysis of covariance were utilized to examine the proposed conceptual model. The results of Experiment 1 (n = 226) demonstrated that seeing other tourists' risk-seeking behavior had a contagion effect on tourists' risk decisions; specifically, other tourists' risk-seeking behavior increased tourists' risk-seeking intention but decreased their risk-aversion intention. Experiment 2 (n = 528) revealed the mediation effect of approach/avoidance motivation between the relationship of other tourists' risk-seeking and tourists' risk-seeking/avoidance intentions. Experiment 3 (n = 526) confirmed that destination management deterrence counteracted the behavioral contagion effect of tourist risk-seeking and induced more risk avoidance. Experiment 4 (n = 452) provided a holistic test of the conceptual model, demonstrating the robustness and validity of the findings. This study reveals the formation mechanism of tourists’ risk decision-making from a behavioral contagion perspective and offers management insights for tourist safety.

The contagious effect of bullying knowledge hiding: exploring the role of job stress and power values

PurposeBullying knowledge hiding has been recently identified as a manifestation of knowledge hiding behavior. As a relatively new concept, it is still underexplored. Previous research has focused on the antecedents of bullying hiding. However, there is a lack of research on the negative consequences that bullying hiding may have on employees. This study aims to uncover the effects of supervisor bullying hiding on employees knowledge behavior. The study also aims to examine the moderating effect of power values and the mediating effect of job stress.Design/methodology/approachData were gathered in two waves from 444 employees with higher education in Poland. Data collection was conducted in July and August 2022. A general linear model mediation analysis with jamovi Advanced Mediation Models software was used to examine the hypotheses.FindingsThe results indicate that bullying knowledge hiding by supervisors triggers subordinates’ job stress and aggression in the form of bullying knowledge hiding toward co-workers. Contrary to expectations, job stress does not mediate the relationship between supervisor bullying hiding and subordinate bullying hiding toward co-workers. Power-dominance values, contrary to power-resources values, moderate the above relationship.Practical implicationsAs bullying hiding has significant potential to spread among organizational members, managers seeking to reduce it should check the personal values of job applicants and employees.Originality/valueBased on the behavioral contagion and frustration–aggression–displacement theories, to the best of the author’s knowledge, this study is the first to investigate the relationships between supervisor bullying hiding, job stress, power values and subordinate bullying hiding toward co-workers.

The directional spillover effects and time-frequency nexus between stock markets, cryptocurrency, and investor sentiment during the COVID-19 pandemic

PurposeThis paper aims to analyze the connectedness between Gulf Cooperation Council (GCC) stock market index and cryptocurrencies. It investigates the relevant impact of RavenPack COVID sentiment on the dynamic of stock market indices and conventional cryptocurrencies as well as their Islamic counterparts during the onset of the COVID-19 crisis.Design/methodology/approachThe authors rely on the methodology of Diebold and Yilmaz (2012, 2014) to construct network-associated measures. Then, the wavelet coherence model was applied to explore co-movements between GCC stock markets, cryptocurrencies and RavenPack COVID sentiment. As a robustness check, the authors used the time-frequency connectedness developed by Barunik and Krehlik (2018) to verify the direction and scale connectedness among these markets.FindingsThe results illustrate the effect of COVID-19 on all cryptocurrency markets. The time variations of stock returns display stylized fact tails and volatility clustering for all return series. This stressful period increased investor pessimism and fears and generated negative emotions. The findings also highlight a high spillover of shocks between RavenPack COVID sentiment, Islamic and conventional stock return indices and cryptocurrencies. In addition, we find that RavenPack COVID sentiment is the main net transmitter of shocks for all conventional market indices and that most Islamic indices and cryptocurrencies are net receivers.Practical implicationsThis study provides two main types of implications: On the one hand, it helps fund managers adjust the risk exposure of their portfolio by including stocks that significantly respond to COVID-19 sentiment and those that do not. On the other hand, the volatility mechanism and investor sentiment can be interesting for investors as it allows them to consider the dynamics of each market and thus optimize the asset portfolio allocation.Originality/valueThis finding suggests that the RavenPack COVID sentiment is a net transmitter of shocks. It is considered a prominent channel of shock spillovers during the health crisis, which confirms the behavioral contagion. This study also identifies the contribution of particular interest to fund managers and investors. In fact, it helps them design their portfolio strategy accordingly.

Applying Behavioral Contagion Theory to Examining Young Adults’ Participation in Viral Social Media Challenges

Viral social media challenges have erupted across multiple social media platforms. While social media users participate in prosocial challenges designed to support good causes, like the Ice Bucket Challenge, some challenges (e.g., Cinnamon Challenge) can also potentially be dangerous. To understand the influential factors, experiences, and reflections of young adults who participated in a viral social media challenge in the past, we conducted interviews with 30 college students (ages 18–27). We applied behavioral contagion theory as a qualitative lens to understand whether this theory could help explain the factors that contributed to their participation. We found that behavior contagion theory was useful but not fully able to explain how and why young social media users engaged in viral challenges. Thematic analyses uncovered that overt social influence and intrinsic factors (i.e., social pressure, entertainment value, and attention-seeking) also played a key role in challenge participation. Additionally, we identified divergent patterns between prosocial and potentially risky social media challenges. Those who participated in prosocial challenges appeared to be more socially motivated as they saw more similarities between themselves and the individuals that they observed performing the challenges and were more likely to be directly encouraged by their friends to participate. In contrast, those who performed potentially risky challenges often did not see similarities with other challenge participants, nor did they receive direct encouragement from peers; yet, half of these participants said they would not have engaged in the challenge had they been more aware of the potential for physical harm. We consider the benefits and risks that viral social media challenges present for young adults with the intent of optimizing these interactions by mitigating risks, rather than discouraging them altogether.

Mechanisms of copying, social learning, and imitation in animals

When an animal matches the behavior of another animal of the same species it likely has evolutionary value because that behavior often avoids the negative outcomes that may accompany trial and error learning. Psychologists have been interested in the mechanisms that might be responsible for the copying behavior. Flocking behavior, an example of behavioral contagion, for example, is likely to be under genetic control. Alternatively, if an animal needs to acquire a new behavior to obtain a reinforcer, the mere presence of another animal may influence motivation, and perhaps also performance. Also, when observing the performance of a response, attention to the manipulated object may be sufficient to facilitate learning. Furthermore, a distinction can be made between imitating the movements of the demonstrator and learning the relations between the manipulated object and the reinforcer (learned affordance). Research using the two-action procedure controls for all of these alternative mechanisms and shows what appears to be evidence for a more cognitive form of imitation. Although human children show a remarkable propensity to imitate there is evidence that many other species (not only other apes, other mammals, and bird species) show evidence that they too will imitate the behavior of others, under appropriate conditions. These results suggest that imitation, thought to be a conceptually cognitive behavior, is widely distributed among many animal species.

From target to actor: Contagion of honesty and deception across buyer–supplier negotiations

AbstractUnderstanding negotiators' decision‐making processes in buyer–supplier relationships has been of key interest to behavioral operations and supply chain management researchers. We hypothesize that through the exposure to various counterparts in the supply chain network, negotiators' behaviors are influenced by others' behaviors and prone to behavioral contagion—where the target adopts the behavior he/she is subjected to and exhibits it toward a nonpartisan counterpart. This paper examines such contagion where targets turn into actors of honesty and deception across buyer–supplier negotiations. We analyzed text responses from two studies employing scenario‐based negotiation experiments with 350 and 424 individuals with B2B sales experience and tested for the effects of previously received behavior (honesty/deception) and different frequency levels of the received behavior. Our results show contagion effects for honesty and deception in both studies. These effects are largely independent from the frequency with which the behaviors have been received, suggesting that a low stimulus frequency suffices to induce contagion of honest and deceptive behaviors across buyer–supplier negotiations. Interestingly, in contrast to our hypothesized key mechanism based on the extant literature, neither injunctive nor descriptive social norms mediated the relationship between received and acted behaviors. We offer alternative explanations and discuss implications for theory and practice.

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

Simple SummaryIn 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.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.

Performance Benefits of Employees’ Own and Their Coworkers’ Nonlimited Willpower Beliefs

The limited-resource perspective provides a primary account of whether people fail to keep persistent in the face of difficulties. A well-documented idea is that any act of self-control efforts will consume people’s willpower (i.e., their capacity to exert self-control) and impair their further self-regulation attempts in persistence. Extending this limited-resource perspective, the present research first brings in implicit theories about willpower to the work context by arguing that whether people believe willpower is a limited or nonlimited resource will affect their job persistence and subsequent job performance. By examining one’s own and interpersonal influence of implicit willpower beliefs, we explore how focal employees’ and coworkers’ willpower beliefs, respectively, affect focal employees’ job performance. Specifically, focal employees’ willpower belief affects job performance through job persistence. In parallel, to examine how coworkers’ willpower belief influences focal employees’ job performance, we theorize a behavioral contagion process whereby coworkers’ job persistence triggered by their willpower belief can be learned by the focal employee to exhibit job persistence themselves, which in turn increases job performance. Further, we theorize that such behavioral contagion effect is stronger when there is lower variance of coworkers’ job persistence. Results based on two multi-wave, multi-source field studies provide consistent support for our hypotheses. We discuss how our findings contribute to the literatures on implicit theories about willpower and behavioral contagion, and provide practical implications for organizations.

News coverage and mass shootings in the US

We study the potential effect of mass-shooting-related television news in the US on subsequent mass shootings from 2006–2017. To circumvent endogeneity, our identification strategy relies on unpredictable disasters in countries home to substantial numbers of US emigrants crowding out shooting news. Instrumental variable and reduced form regressions consistently suggest a positive and statistically significant effect. This result remains consistent throughout a battery of robustness checks. In terms of magnitude, a one standard deviation increase in shooting news raises mass shootings by approximately 73% of a standard deviation. We then explore potential mechanisms, broadly delineating (i) the ideation of murder, (ii) fame seeking, and (iii) behavioral contagion. The number of murders in general remains orthogonal to shooting news, and mass shootings are not more likely on days with predictable news pressure (e.g., during the Olympics or the Super Bowl). However, mass shootings are more likely after anniversaries of the most deadly historical mass shootings. Taken together, these results lend support to a behavioral contagion mechanism following the public salience of mass shootings.

The impact of the COVID-19 pandemic on the nexus between the investor’s sentiment and the financial market dynamics: evidence from the Chinese market

PurposeThis study aims to investigate the impact of the COVID-19 pandemic on both of stock prices and investor's sentiment in China during the onset of the COVID-19 crisis.Design/methodology/approachIn this study, the ADCC-GARCH model was used to analyze the asymmetric volatility and the time-varying conditional correlation among the Chinese stock market, the investors' sentiment and its variation. The authors relied on Diebold and Yilmaz (2012, 2014) methodology to construct network-associated measures. Then, the wavelet coherence model was applied to explore the co-movements between these variables. To check the robustness of the study results, the authors referred to the RavenPack COVID sentiments and the Chinese VIX, as other measures of the investor's sentiment using daily data from December 2019 to December 2021.FindingsUsing the ADCC-GARCH model, a strong co-movement was found between the investor's sentiment and the Shanghai index returns during the COVID-19 pandemic. The study results provide a significant peak of connectivity between the investor's sentiment and the Chinese stock market return during the 2015–2016 and the end of 2019–2020 turmoil periods. These periods coincide, respectively, with the 2015 Chinese economy recession and the COVID-19 pandemic outbreak. Furthermore, the wavelet coherence analysis confirms the ADCC results, which revealed that the used proxies of the investor's sentiment can detect the Chinese investors' behavior especially during the health crisis.Practical implicationsThis study provides two main types of implications: on the one hand, for investors since it helps them to understand the economic outlook and accordingly design their portfolio strategy and allocate decisions to optimize their portfolios. On the other hand, for portfolios managers, who should pay attention to the volatility spillovers between investor sentiment and the Chinese stock market to predict the financial market dynamics during crises periods and hedge their portfolios.Originality/valueThis study attempted to examine the time-varying interactions between the investor's sentiment proxies and the stock market dynamics. Findings showed that the investor's sentiment is considered a prominent channel of shock spillovers during the COVID-19 crisis, which typically confirms the behavioral contagion theory.

Scale-free behavioral cascades and effective leadership in schooling fish

Behavioral contagion and the presence of behavioral cascades are natural features in groups of animals showing collective motion, such as schooling fish or grazing herbivores. Here we study empirical behavioral cascades observed in fish schools defined as avalanches of consecutive large changes in the heading direction of the trajectory of fish. In terms of a minimum turning angle introduced to define a large change, avalanches are characterized by distributions of size and duration showing scale-free signatures, reminiscent of self-organized critical behavior. We observe that avalanches are generally triggered by a small number of fish, which act as effective leaders that induce large rearrangements of the group’s trajectory. This observation motivates the proposal of a simple model, based in the classical Vicsek model of collective motion, in which a given individual acts as a leader subject to random heading reorientations. The model reproduces qualitatively the empirical avalanche behavior observed in real schools, and hints towards a connection between effective leadership, long range interactions and avalanche behavior in collective movement.

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

Simple SummaryResearch suggests that contagious yawning evolved to synchronize activity and vigilance within groups. To date, yawning has shown to be contagious in a wide range of mammalian species, including humans, great apes, some monkey species, domesticated dogs and pigs, wolves, lions, and rats. However, yawn contagion has only been previously documented in one bird species: budgerigars (Melosittacus undulatus). Here, we sought to examine whether yawning was contagious among juvenile common ravens (Corvus corax). By observing two small and undisturbed captive groups, we also assessed the contagious nature of other frequently observed and potentially contagious behaviors: stretching, scratching, and shaking. Overall, we found no evidence for behavioral contagion. Given the limitations to the observational methods, however, we suggest future experimental research be conducted to support these findings.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.

Simulation Research on the Infection of Unsafe Behavior of Employees Based on Social Network

In order to study the characteristics of unsafe behavior contagion, based on the small world network, an unsafe behavior contagion model with behavioral rules such as homogenization aggregation, second-degree relationship distance of infection, influence paradox, and attenuation of behavioral contagion was constructed. The Netlogo platform was used for simulation. According to the results, it is found that the transmission of unsafe behavior has the contagion characteristics of hysteresis, emerging, and progressiveness. Whether the contagion behaviors occur was determined by the average path length of the network. The strong connection relationship in the network structure would trigger the infection of unsafe behavior. There was a significant positive correlation between the node distribution level of the network structure and the time-consuming cycle of unsafe behavior. Through research and exploration of the formation law and diffusion characteristics of unsafe behaviors in social networks, it is expected to provide theoretical support and direction guidance for the prevention and control of unsafe behaviors in social networks, thereby promoting the improvement of individual and organizational safety performance.

People that score high on psychopathic traits are less likely to yawn contagiously

Considerable variation exists in the contagiousness of yawning, and numerous studies have been conducted to investigate the proximate mechanisms involved in this response. Yet, findings within the psychological literature are mixed, with many studies conducted on relatively small and homogeneous samples. Here, we aimed to replicate and extend upon research suggesting a negative relationship between psychopathic traits and yawn contagion in community samples. In the largest study of contagious yawning to date (N = 458), which included both university students and community members from across 50 nationalities, participants completed an online study in which they self-reported on their yawn contagion to a video stimulus and completed four measures of psychopathy: the primary and secondary psychopathy scales from the Levenson Self-Report Psychopathy Scale (LSRPS), the psychopathy construct from the Dirty Dozen, and the Psychopathic Personality Traits Scale (PPTS). Results support previous findings in that participants that yawned contagiously tended to score lower on the combined and primary measures of psychopathy. That said, tiredness was the strongest predictor across all models. These findings align with functional accounts of spontaneous and contagious yawning and a generalized impairment in overall patterns of behavioral contagion and biobehavioral synchrony among people high in psychopathic traits.

The importance of peer imitation on smoking initiation over time: a dynamical systems approach.

A recent Institute of Medicine Report calls for explicit modeling of smoking initiation, cessation and addiction processes. We introduce a model of smoking initiation that explicitly teases out the percentage of initiation due to social pressures, which we call "peer-imitation," and the percentage due to other factors, such as media ads, family smoking, and psychological factors, which we call "self-initiation." We propose a dynamic non-linear behavioral contagion model of smoking initiation and employ data from the National Survey on Drug Use and Health to estimate the relative contributions of imitation and self-initiation to the overall smoking initiation process. Although the percent of total smoking due to peer imitation has been trending downward over time, it remains higher than the percent due to self-initiation. We note unexpected changes for the 2007 cohort, and we discuss possible implications for intervention and for the spread of e-cigarettes.