We predict a riot: inequity, relative deprivation and collective destruction in the laboratory

Riots are unpredictable and dangerous. Our understanding of the factors that cause riots is based on correlational observations of population data, or post hoc introspection of individuals. To complement these accounts, we developed innovative experimental techniques, investigated the psychological factors of rioting and explored their consequences with agent-based simulations. We created a game, ‘Parklife’, that physically co-present participants played using smartphones. In two teams, participants tapped on their screen to grow trees and flowerbeds on separate but adjacent virtual parks. Participants could also tap to vandalize the other team's park. In some conditions, we surreptitiously introduced inequity between the teams so that one (the disadvantaged team) had to tap more for each reward. The experience of inequity caused the disadvantaged team to engage in more destruction, and to report higher relative deprivation and frustration. Agent-based models suggested that acts of destruction were driven by the interaction between individual level of frustration and the team's behaviour. Our results provide insights into the psychological mechanisms underlying collective action

Animal linguistics: a primer

The evolution of language has been investigated by several research communities, including biologists and linguists, striving to highlight similar linguistic capacities across species. To date, however, no consensus exists on the linguistic capacities of non-human species. Major controversies remain on the use of linguistic terminology, analysis methods and behavioural data collection. The field of ‘animal linguistics’ has emerged to overcome these difficulties and attempt to reach uniform methods and terminology. This primer is a tutorial review of ‘animal linguistics’. It describes the linguistic concepts of semantics, pragmatics and syntax, and proposes minimal criteria to be fulfilled to claim that a given species displays a particular linguistic capacity. Second, it reviews relevant methods successfully applied to the study of communication in animals and proposes a list of useful references to detect and overcome major pitfalls commonly observed in the collection of animal behaviour data. This primer represents a step towards mutual understanding and fruitful collaborations between linguists and biologists

Skin temperature and reproductive condition in wild female chimpanzees

The research was supported by a Fyssen fellowship awarded to Guillaume Dezecache, and has received funding from the European Union’s Seventh Framework Programme for research, technological development and demonstration under grant agreement (No 283871)Infrared thermal imaging has emerged as a valuable tool in veterinary medicine, in particular for evaluating reproductive processes. Here, we explored differences in skin temperature of twenty female chimpanzees in Budongo Forest, Uganda, four of which were pregnant during data collection. Based on previous literature in other mammals, we predicted increased skin temperature of maximally swollen reproductive organs of nonpregnant females when approaching peak fertility. For pregnant females, we made the same prediction because it has been argued that female chimpanzees have evolved mechanisms to conceal pregnancy, including swellings of the reproductive organs, conspicuous copulation calling, and solicitation of male mating behaviour, to decrease the infanticidal tendencies of resident males by confusing paternity. For non-pregnant females, we found slight temperature increases towards the end of the swelling cycles but no significant change between the fertile and non-fertile phases. Despite their different reproductive state, pregnant females had very similar skin temperature patterns compared to non-pregnant females, suggesting little potential for males to use skin temperature to recognise pregnancies, especially during maximal swelling, when ovulation is most likely to occur in non-pregnant females. We discuss this pattern in light of the concealment hypothesis, i.e., that female chimpanzees have evolved physiological means to conceal their reproductive state during pregnancyPublisher PDFPeer reviewe

Skin temperature changes in wild chimpanzees upon hearing vocalizations of conspecifics

The authors are grateful to the Royal Zoological Society of Scotland for providing core funding to the Budongo Conservation Field Station. The research was supported by a Fyssen fellowship awarded to GD, funding from the European Union’s Seventh Framework Programme for research, technological development and demonstration (grant agreement no 283871), and the Swiss National Science Foundation (PZ00P3_154741) awarded to CDD.A growing trend of research using infra-red thermography (IRT) has shown that changes in skin temperature, associated with activity of the autonomic nervous system, can be reliably detected in human and non-human animals. A contact-free method, IRT provides the opportunity to uncover emotional states in free-ranging animals during social interactions. Here, we measured nose and ear temperatures of wild chimpanzees of Budongo Forest, Uganda, when exposed to naturally occurring vocalizations of conspecifics. We found a significant temperature decrease over the nose after exposure to conspecifics’ vocalizations, whereas we found a corresponding increase for ear temperature. Our study suggests that IRT can be used in wild animals to quantify changes in emotional states in response to the diversity of vocalizations, their functional significance and acoustical characteristics. We hope that it will contribute to more research on physiological changes associated with social interactions in wild animals.Publisher PDFPeer reviewe

Vocal functional flexibility : what it is and why it matters

The primary funder of this research was the ‘University of Portsmouth, Department of Psychology’ and the grant ID is ‘PhD Bursary’ which was awarded to ‘Derry Taylor’.Human speech is marked by a signal–function decoupling, the capacity to produce sounds that can fulfil a variety of functions, in contrast to nonverbal vocalizations such as laughter, cries and screams, which are functionally more rigid. It has been argued that this decoupling provides an essential foundation for the emergence of language, in both ontogeny and phylogeny. Although language has a deep evolutionary history, whether this capacity for vocal functional flexibility also exists in the vocal systems of nonhuman animals has been much overlooked. Reasons are multiple. Here, we propose to diagnose the problems that have thus far hindered progress on understanding the evolutionary basis of functional flexibility, an issue which can shed broader light on the evolution of language. In particular, we aim to clarify what vocal functional flexibility is, why it matters, why we believe it should be investigated in nonhuman animals and how this could be best achieved.Publisher PDFPeer reviewe

A quantification of the reliability of self-reports following a simulated stressful event

Interviews and surveys are the most commonly used data-gathering and data-generating techniques when investigating human behaviour in emergencies. However, these approaches suffer from several limitations, including potential errors in memory accuracy, a lack of quantitative reliability. This study focuses on a survey performed on participants who had taken part in a stressful experiment. The survey was carried out three months afterwards, asking them to recall their experience. Analysis of this data quantitatively assesses their recall, across multiple different domains. This study observed several differences between experimental and control group participants, as well as differences between participants in VR and Physical experimental groups. However, it observes no increase in confabulation as a result of increased stress. The outcome of this study is to provide insight into the quantitative reliability of interviews and surveys of people involved in emergencies

The development of communication in alarm contexts in wild chimpanzees

Funding: The Royal Zoological Society of Scotland provided core funding to the Budongo Conservation Field Station. This research was financially supported by FP7-IDEAS-ERC (324115), the Agence Nationale de la Recherche (ANR-10-LABX-0087 IEC and ANR-10-IDEX-0001-02 PSL) and by the Swiss National Science Foundation (31003A_166458).Animals have evolved a range of communicative behaviours in the presence of danger. Although the mechanisms and functions of some of these behaviours have been relatively well researched, comparatively little is known about their ontogeny, including how animals learn to inform social partners about impending danger. In adult chimpanzees, behaviours in response to dangers involve several channels, particularly alarm calls and simultaneous gaze alternations with nearby recipients. Gaze alternations may allow inexperienced individuals to learn from more experienced ones by assessing their reactions to unfamiliar objects or events, but they may also provide the basis for more advanced social referencing. Here, we were interested in the development of these two common behaviours, alarm calling and gaze alternations, in wild chimpanzees (Pan troglodytes schweinfurthii) confronted with a threat. Using a cross-sectional design, we investigated those in 8 infant and 8 juveniles by experimentally exposing them to an unfamiliar but potentially dangerous object, a large, remotely controlled, moving spider model. For alarm calling, we found a positive relation with age, starting at around 28 months, although alarm calls were not consistently emitted until after 80 months. For gaze alternations, we found no age effect, with some of the youngest infants already showing the behaviour. Although its function remains unclear in infant and juvenile chimpanzees, gaze alternations emerge early in chimpanzee development. Alarm calling may require more advanced developmental stages, such as greater perceptual abilities, categorical capacities or more sophisticated social cognition, i.e. an understanding that danger is a collective experience that requires communication.Publisher PDFPeer reviewe

Social influence matters: We follow pandemic guidelines most when our close circle does

Why do we adopt new rules, such as social distancing? Although human sciences research stresses the key role of social influence in behaviour change, most COVID-19 campaigns emphasize the disease’s medical threat. In a global data set (n = 6,674), we investigated how social influences predict people’s adherence to distancing rules during the pandemic. Bayesian regression analyses controlling for stringency of local measures showed that people distanced most when they thought their close social circle did. Such social influence mattered more than people thinking distancing was the right thing to do. People’s adherence also aligned with their fellow citizens, but only if they felt deeply bonded with their country. Self-vulnerability to the disease predicted distancing more for people with larger social circles. Collective efficacy and collectivism also significantly predicted distancing. To achieve behavioural change during crises, policymakers must emphasize shared values and harness the social influence of close friends and family

Facial complexity in sun bears: exact facial mimicry and social sensitivity

Abstract Facial mimicry is a central feature of human social interactions. Although it has been evidenced in other mammals, no study has yet shown that this phenomenon can reach the level of precision seem in humans and gorillas. Here, we studied the facial complexity of group-housed sun bears, a typically solitary species, with special focus on testing for exact facial mimicry. Our results provided evidence that the bears have the ability to mimic the expressions of their conspecifics and that they do so by matching the exact facial variants they interact with. In addition, the data showed the bears produced the open-mouth faces predominantly when they received the recipient’s attention, suggesting a degree of social sensitivity. Our finding questions the relationship between communicative complexity and social complexity, and suggests the possibility that the capacity for complex facial communication is phylogenetically more widespread than previously thought