Dogs functionally respond to and use emotional information from human expressions.

Emotions are critical for humans, not only feeling and expressing them, but also reading the emotional expressions of others. For a long time, this ability was thought to be exclusive to people; however, there is now evidence that other animals also rely on emotion perception to guide their behaviour and to adjust their actions in such way as to guarantee success in their social groups. This is the case for domestic dogs, who have tremendously complex abilities to perceive the emotional expressions not only of their conspecifics but also of human beings. In this paper we discuss dogs' capacities to read human emotions. More than perception, though, are dogs able to use this emotional information in a functional way? Does reading emotional expressions allow them to live functional social lives? Dogs can respond functionally to emotional expressions and can use the emotional information they obtain from others during problem-solving, that is, acquiring information from faces and body postures allows them to make decisions. Here, we tackle questions related to the abilities of responding to and using emotional information from human expressions in a functional way and discuss how far dogs can go when reading our emotions.

How Do Dogs Behave When Presented with Situations of Different Emotional Valences?

Dogs are good models for studying behaviour and cognition as they have complex social capabilities. In the current study, we observed how human emotional valences (positive, neutral and negative) affected aspects of dogs' behaviour. We expected that dogs would exhibit more approaching behaviours in the positive condition and more signs of avoidance in the negative one. We analysed videos of 70 adult pet dogs of various breeds taken from an experiment in which one of two actors expressed an emotion and dogs could freely explore the environment for 30 s. Our results show that dogs exhibit differential behaviour when presented with different emotional valences. Two behaviours arose that might be linked to a reciprocal positive emotional state in dogs: tail raised between 90° and 180° and physical contact during sniffing. These behaviours are associated with an active search for information. In the positive conditions, dogs were more willing to explore the social environment and gather information from the actors.

Size, skull shape and age influence the temperament of domestic dogs.

Studies have investigated the relationship between dogs' morphological characteristics and behavioural dimensions, but little is discussed about this relationship in the context of dogs' responses to emotion eliciting stimuli and temperament. Based on the assumption that the developmental trajectory of behaviour and emotion processing is impacted by the interaction between organisms and environment, we analysed whether dogs' characteristics - that determine how they perceive and interact with their surroundings - affect temperament profiles. We looked at size, height, weight, skull morphology, age, sex, reproductive status, and breed of a sample of Brazilian domestic dogs' and their temperament (measured as Positive and Negative Activation), obtained via the PANAS questionnaire for dogs. We tested possible main effects and first-order interactions in linear mixed models. Younger dogs showed higher positive activation (i.e. sensitivity to positive stimuli; play and treats). For short snouted dogs, the older the dog, less was the negative activation (i.e. sensitivity to negative stimuli; punishment). And for long snouted dogs, larger dogs showed lower negative activation. Weight alone also showed an effect, with heavier dogs having less sensitivity to negative stimuli. Overall, our study demonstrated how morphology and age are important factors that influence temperament expression and emotional reactivity in dogs.

Dogs can infer implicit information from human emotional expressions.

The ability to infer emotional states and their wider consequences requires the establishment of relationships between the emotional display and subsequent actions. These abilities, together with the use of emotional information from others in social decision making, are cognitively demanding and require inferential skills that extend beyond the immediate perception of the current behaviour of another individual. They may include predictions of the significance of the emotional states being expressed. These abilities were previously believed to be exclusive to primates. In this study, we presented adult domestic dogs with a social interaction between two unfamiliar people, which could be positive, negative or neutral. After passively witnessing the actors engaging silently with each other and with the environment, dogs were given the opportunity to approach a food resource that varied in accessibility. We found that the available emotional information was more relevant than the motivation of the actors (i.e. giving something or receiving something) in predicting the dogs' responses. Thus, dogs were able to access implicit information from the actors' emotional states and appropriately use the affective information to make context-dependent decisions. The findings demonstrate that a non-human animal can actively acquire information from emotional expressions, infer some form of emotional state and use this functionally to make decisions.

Effect of different experiences with humans in dogs' visual communication.

Dogs are particularly skillful in communicating with humans, and growing evidence points towards the importance of both species intertwined evolutionary history and intense daily partnership. Gaze alternation is a communicative behavior used by dogs from a very young age and is affected by factors such as aging and experience. We analyzed how different degrees of daily human interaction affect dogs' gazing behavior in the unsolvable task, where a desired food becomes inaccessible. Three groups with different degrees of daily exposure to humans were compared: pet dogs that live inside the house, pet dogs that live outside the house, and shelter dogs. We found no difference in latency to the first gaze, but pet dogs did show a higher proportion of individuals engaging in gaze alternation, a higher number of gaze alternations, and a longer duration of gaze than shelter dogs. Additionally, dogs living inside the house gazed more at the experimenter than dogs living outside. Overall, our results indicate a strong influence of experience over the development and use of these communicative behaviors in dogs, with groups that are closer to people in their daily lives being more willing to communicate with humans as a strategy to obtain a desired goal.

Do Emotional Cues Influence the Performance of Domestic Dogs in an Observational Learning Task?

Using social information is not indiscriminate and being able to choose what to copy and from whom to copy is critical. Dogs are able to learn socially, to recognize, and respond to dog as well as human emotional expressions, and to make reputation-like inferences based on how people behave towards their owner. Yet, the mechanisms dogs use for obtaining and utilizing social information are still to be fully understood, especially concerning whether emotional cues influence dogs' social learning. Therefore, our main aim was to test the hypothesis that an emotionally charged (negative, positive, or neutral) interaction with the demonstrator of a "V" detour task prior to testing would affect subjects' performance, by: (i) changing the value of the information provided by the demonstrator or (ii) changing the valence of the learning environment. Our experimental design consisted of three phases: pre-test (subjects were allowed to solve the task alone); emotional display (dogs watched the unfamiliar human behaving in either a positive, negative or neutral way towards their owner); test (demonstrator showed the task and subjects were allowed to move freely). Only dogs that failed in pre-test were considered for analysis (n = 46). We analyzed four dependent variables: success, time to solve the task, latency to reach the fence and matching the side of demonstration. For each, we used four models (GEEs and GLMMs) to investigate the effect of (1) demographic factors; (2) experimental design factors (including emotional group); (3) behavior of the dog; and (4) side chosen and matching. All models took into account all trials (random effect included) and the first trials only. Our findings corroborate previous studies of social learning, but present no evidence to sustain our hypothesis. We discuss the possibility of our stimuli not being salient enough in a task that involves highly motivating food and relies on long and highly distracting interval between phases. Nevertheless, these results represent an important contribution to the study of dog behavior and social cognition and pave the way for further investigations.

Group cohesiveness in children free-play activity: A social network analysis.

Despite the ethnic diversity and presence of Amerindian communities in all Brazilian states, the indigenous population suffers from a long process of invisibility and stereotyping. Aiming to increase interethnic associations, together with Mbya-Guarani leaders we promoted interventions in which indigenous and non-indigenous children shared free playtime. We hypothesised that free play activity would stimulate group cohesiveness, mitigating ethnic group avoidance in children's playgroups. Twenty-one Mbya-Guarani and 61 non-indigenous children participated in two "Encounters for Play." We recorded children's social interactions during the free playtimes. We selected the first and last 10 minutes of each encounter and performed scans every 30s registering spatial proximity (children who were up to 1 m of each other) and play. Then, we applied Social Network Analysis to explore the children's association pattern at the beginning and end of playtime in each encounter. Our results show free play activity was effective in stimulating group cohesiveness. Children' proximity association pattern and playgroup configuration changed between clips, and there was a significant correlation between both categories' associations. We conclude that the encounters have potential applicability as an intervention to mitigate ethnic group avoidance in children.

Interweaving social and manipulative development in early infancy: Some direction for infant caregiving.

Early infancy has been neglect not having the best opportunities to promote social motor and cognitive development. The maturational concept considering young infants as passive beings provide a misguided view of the developmental process. The human infant is an active being from the very beginning of life. In the social and physical world, they can, by observing and imitating, perform complex actions involving different motor behaviours. In the present review we argue that imitation and manipulative actions are integrated in Expressive Action System (Reed, 1996) where baby-caregiver social interaction is the link between the use and exploration of objects in the world. We present evidence that neonatal imitation and manipulation activities are connected and thus, we propose stimulation practices based in seminal experimental designs where infants should be positioned in favourable postures to observe others acting in the world. This will have an impact on the way that early infants understand the social world and the chain of actions possible in this environment.

A review of the unsolvable task in dog communication and cognition: comparing different methodologies.

Communication between dogs and humans is a topic of growing interest, and the "unsolvable task" is a common method used to measure human-directed communication. In this task, dogs learn how to solve a problem to obtain a reward. After a fixed number of trials, the reward becomes impossible to access, arguably leading to communicative attempts from the dog. Although useful to observe dogs' communicative behaviors in a fairly naturalistic situation, the methodology varies among studies regarding apparatus, number of trials, and other factors. The proxies used, for instance, gaze duration or frequency of gaze alternation, also vary, and there are discrepancies and a debate regarding what the task actually measures. Therefore, in this study, we reviewed the usage of the unsolvable task in canids of the genus Canis, searching Web of Science and Scopus for the terms "dog*", "Canis", "dingo*", "wolf" or "wolves" in the title and "unsolvable task" or "impossible task" in the topic. We included thirty-five studies in this review and discussed their different methodologies and proxies, such as different apparatuses, number of solvable trials, and different interpretations of "looking back", pointing out how they can affect results and hinder comparisons. Lastly, we used current data to propose strategies to homogenize the use of this important paradigm, with an ethogram of possible behaviors and their interpretation and a predefined set of methodological aspects for future research.

Revisiting the fourth dimension of tool use: how objects become tools for capuchin monkeys.

Culture allows humans to adapt to a diversity of contexts. Participatory experience in technical activities and activity with artefacts provide the basis for learning traditional technical skills. Some populations of non-human animals use tools. The ways in which artefacts influence the development of a traditional skill in non-human species can provide insight into essential supports for technical traditions in humans and shared learning processes across species. In wild bearded capuchins, nut cracking leaves edible pieces of nuts, nut shells and stones used as hammers at anvil sites. We addressed how mastery of cracking nuts by young monkeys is associated with interactions with these objects. We studied monkeys' reuse of nuts, hammers and anvils and the outcome of attempts to crack nuts, and from these data derived their behavioural variability and proficiency in nut cracking. Behavioural variability was the most robust predictor of whether a monkey collects pieces of nuts cracked by others or reuses stones and nuts, and was a stronger predictor of proficiency than age. Young monkeys were increasingly likely to reuse the stone used by another after the other monkey had left the anvil as they increasingly focused their behaviour on actions relevant to cracking nuts.

The Development of Context-Sensitive Attention in Urban and Rural Brazil.

Human perception differs profoundly between individuals from different cultures. In the present study, we investigated the development of context-sensitive attention (the relative focus on context elements of a visual scene) in a large sample (N = 297) of 5- to 15-year-olds and young adults from rural and urban Brazil, namely from agricultural villages in the Amazon region and the city of São Paulo. We applied several visual tasks which assess context-sensitive attention, including an optical illusion, a picture description, a picture recognition and a facial emotion judgment task. The results revealed that children and adults from the urban sample had a higher level of context-sensitive attention, when compared to children and adults from the rural sample. In particular, participants from São Paulo were more easily deceived by the context elements in an optical illusion task and remembered more context elements in a recognition task than participants from rural Amazon villages. In these two tasks, context-sensitivity increased with age. However, we did not find a cultural difference in the picture description and the facial emotion judgment task. These findings support the idea that visual information processing is highly dependent on the culture-specific learning environments from very early in development. Specifically, they are more consistent with accounts that emphasize the role of the visual environment, than with the social orientation account. However, they also highlight that further research is needed to disentangle the diverse factors that may influence the early development of visual attention, which underlie culture-specific developmental pathways.

Infants' Characteristics and Skills: Dissolving the Nature/Nurture Dichotomy / Características e Competências dos Bebês: Rompendo a Dicotomia Inato/Aprendido / Características y Habilidades de los Bebés: Rompendo la Dicotomía Innato /Aprendido

Abstract According to an emergent group of researchers, systemic, relational and evolutionary thought is needed to understand the development of organisms' characteristics and competences. In this paper, we first introduce the prevalent view on the biological basis of behavior, based on the New Synthesis of Modern Biology. Next, we present the critical view of those who defend Extended Evolutionary Synthesis. The existing debate between the different perspectives is illustrated by studies on infants' sensorial capacities, attachment, and neonatal imitation. Possible interpretations, based on the theoretical approaches presented, lead to a reflection on the innate/acquired dichotomy: from the prevailing view, this dichotomy is overcome because the interaction between the innate and the acquired is being considered to explain the characteristics of living beings. A further reflection on the developmental processes involved in the emergence of behavior, on the concepts of what is learning and what is innate leads to the dissolution of this dichotomy.

Resumo Uma corrente emergente de pesquisadores vem defendendo que a compreensão sobre o desenvolvimento das características e competências dos organismos passa pela adoção de um pensamento sistêmico, relacional e também evolucionista. Com o objetivo de apresentar este pensamento, inicialmente discutimos a visão prevalente sobre as bases biológicas do comportamento, que se baseia na Nova Síntese da Biologia Moderna, e, a seguir, expomos a crítica colocada pelos defensores da Síntese Estendida da Evolução. Os debates entre as abordagens serão exemplificados por meio da apresentação de pesquisas sobre as capacidades sensoriais e estabelecimento de vínculo do bebê e a imitação neonatal. As interpretações possíveis, baseadas nas abordagens teóricas apresentadas, desembocam em uma reflexão sobre a dicotomia inato/adquirido: pela visão prevalente, esta dicotomia está superada porque a interação entre o inato e o adquirido vem sendo considerada para explicar as características dos seres vivos. Uma reflexão aprofundada sobre os processos de desenvolvimento envolvidos na emergência do comportamento ressignifica, no entanto, os conceitos de inato e aprendido, levando à dissolução desta dicotomia.

Resumen Una corriente emergente de investigadores viene defendiendo que la comprensión del desarrollo de los carácter y competencias de los organismos implica la adopción de un enfoque sistémico, relacional y evolucionista. Con el fin de presentar este argumento, en principio discutiremos la visión predominante sobre las bases biológicas del comportamiento, soportada en la Nueva Síntesis de la Biología Moderna y, a continuación, expondremos la crítica propuesta por los partidarios de la Síntesis Evolutiva Extendida. El debate entre los enfoques será ejemplificado a través de la presentación de investigaciones sobre capacidades sensoriales, el establecimiento del apego e imitación neonatal. Las posibles interpretaciones desde cada uno de los enfoques teóricos presentados desembocaran en una reflexión sobre la dicotomía innato/ adquirido: el punto de vista predominante sostiene que esta dicotomía se supera cuando se consideran las interacciones innato-adquirido. Una reflexión profunda sobre los procesos de desarrollo, involucrados en la emergencia del comportamiento, conduce a la disolución de la dicotomia innato-aprendido.

Mouth-licking by dogs as a response to emotional stimuli.

Dogs are able to perceptually discriminate emotional displays of conspecifics and heterospecifics and possess the cognitive prototypes for emotional categorisation, however, it remains unclear whether dogs can respond appropriately to this information. One way to assess associations between specific behaviours and the perception of emotionally competent stimuli is to look at other reliable measures that are related to cognitive and physiological processing. Using a cross-modal preferential looking paradigm (Albuquerque et al., 2016), we presented dogs with pairs of facial expressions (positive and negative) combined with an emotionally charged vocalisation (positive or negative) or a control sound (neutral) and coded their mouth-licking behaviour. We found an effect of the valence of the face image dogs were seeing on the onset of the mouth-licking, with higher frequencies of this behaviour in response to the negative faces compared to images with positive valence. However, neither the sound being played nor the interaction between image valence and sound affected the behaviour. We also found an effect of species with mouth-licking occurring more often towards human stimuli. This spontaneous differential behavioural response, combined with previous evidence of cognitive emotional processing in these animals, suggests that dogs may have a functional understanding of emotional expressions.

Synchronized practice helps bearded capuchin monkeys learn to extend attention while learning a tradition.

Culture extends biology in that the setting of development shapes the traditions that individuals learn, and over time, traditions evolve as occasional variations are learned by others. In humans, interactions with others impact the development of cognitive processes, such as sustained attention, that shape how individuals learn as well as what they learn. Thus, learning itself is impacted by culture. Here, we explore how social partners might shape the development of psychological processes impacting learning a tradition. We studied bearded capuchin monkeys learning a traditional tool-using skill, cracking nuts using stone hammers. Young monkeys practice components of cracking nuts with stones for years before achieving proficiency. We examined the time course of young monkeys' activity with nuts before, during, and following others' cracking nuts. Results demonstrate that the onset of others' cracking nuts immediately prompts young monkeys to start handling and percussing nuts, and they continue these activities while others are cracking. When others stop cracking nuts, young monkeys sustain the uncommon actions of percussing and striking nuts for shorter periods than the more common actions of handling nuts. We conclude that nut-cracking by adults can promote the development of sustained attention for the critical but less common actions that young monkeys must practice to learn this traditional skill. This work suggests that in nonhuman species, as in humans, socially specified settings of development impact learning processes as well as learning outcomes. Nonhumans, like humans, may be culturally variable learners.

Eye Contact Is Crucial for Referential Communication in Pet Dogs.

Dogs discriminate human direction of attention cues, such as body, gaze, head and eye orientation, in several circumstances. Eye contact particularly seems to provide information on human readiness to communicate; when there is such an ostensive cue, dogs tend to follow human communicative gestures more often. However, little is known about how such cues influence the production of communicative signals (e.g. gaze alternation and sustained gaze) in dogs. In the current study, in order to get an unreachable food, dogs needed to communicate with their owners in several conditions that differ according to the direction of owners' visual cues, namely gaze, head, eyes, and availability to make eye contact. Results provided evidence that pet dogs did not rely on details of owners' direction of visual attention. Instead, they relied on the whole combination of visual cues and especially on the owners' availability to make eye contact. Dogs increased visual communicative behaviors when they established eye contact with their owners, a different strategy compared to apes and baboons, that intensify vocalizations and gestures when human is not visually attending. The difference in strategy is possibly due to distinct status: domesticated vs wild. Results are discussed taking into account the ecological relevance of the task since pet dogs live in human environment and face similar situations on a daily basis during their lives.

Cultural Influences on Toddlers' Prosocial Behavior: How Maternal Task Assignment Relates to Helping Others.

This cross-cultural study investigates how maternal task assignment relates to toddlers' requested behavior and helping between 18 and 30 months. One hundred seven mother-child dyads were assessed in three different cultural contexts (rural Brazil, urban Germany, and urban Brazil). Brazilian mothers showed assertive scaffolding (serious and insistent requesting), whereas German mothers employed deliberate scaffolding (asking, pleading, and giving explanations). Assertive scaffolding related to toddlers' requested behavior in all samples. Importantly, assertive scaffolding was associated with toddlers' helping in rural Brazil, whereas mothers' deliberate scaffolding related to toddlers' helping behavior in urban Germany. These findings highlight the role of caregivers' socialization practices for the early ontogeny of helping behavior and suggest culture-specific developmental pathways along the lines of interpersonal responsibility and personal choice.

Tufted capuchin monkeys (Sapajus sp) learning how to crack nuts: does variability decline throughout development?

We investigated the process of nut-cracking acquisition in a semi-free population of tufted capuchin monkeys (Sapajus sp) in São Paulo, Brazil. We analyzed the cracking episodes from monkeys of different ages and found that variability of actions related to cracking declined. Inept movements were more frequent in juveniles, which also showed an improvement on efficient striking. The most effective behavioral sequence for cracking was more frequently used by the most experienced monkeys, which also used non-optimal sequences. Variability in behavior sequences and actions may allow adaptive changes to behavior under changing environmental conditions.

Are dogs sensitive to the human's visual perspective and signs of attention when using a keyboard with arbitrary symbols to communicate?

This study investigated whether dogs take into account the human's direction of attention and visual field when they communicate by means of a keyboard with lexigrams. In order to test this, two dogs, Sofia and Laila, were given the choice between two keyboards, one visible and the other one non-visible from the experimenter's perspective. In one experiment, different barriers were positioned in such way so as to block the experimenter's visibility to one of the keyboards, and, in another experiment we manipulated human's signs of attention, like body orientation and visibility of the eyes. Sofia and Laila consistently preferred to use the keyboard that was in the human's visual field. Laila's choice was also influenced by the human's body orientation. Results suggested that the subjects are sensitive to the human's visual access to the keyboard when they use it to ask for food.(AU)

Este estudo investigou se cães levam em conta a direção da atenção e o campo visual do ser humano quando se comunicam por meio de um teclado com lexigramas. Para tanto, duas cadelas, Sofia e Laila, foram submetidas a uma situação em que podiam escolher entre dois teclados, um deles visível e outro não-visível sob a perspectiva do experimentador. Em um experimento, diferentes barreiras foram posicionadas de tal forma a bloquear a visibilidade do experimentador a um dos teclados, e, em outro, experimento manipulamos os sinais de atenção do ser humano, como orientação corporal e visibilidade dos olhos. Sofia e Laila preferiram consistentemente usar o teclado que estava dentro do campo visual do ser humano. A escolha de Laila também foi influenciada pela orientação corporal do ser humano. Os resultados sugerem que as duas são sensíveis ao acesso visual do ser humano ao teclado quando elas o usam para pedir comida.(AU)