Still-face Effect in Dogs (Canis familiaris). A Pilot Study.

The Still-face Paradigm has been widely used for the assessment of emotion regulation in infants, as well as for the study of the mother-child relationship. Given the close bond that dogs have with humans, the purpose of this research was to evaluate, through an exploratory descriptive study, the presence of the Still-face effect in dogs. To this end, a group of Beagle dogs were exposed to three one-minute phases in which first, an unknown experimenter interacted actively and positively with each dog (Interaction). Then, suddenly, she interrupted the interaction and remained passive, with a non-expressive face and without speaking or petting the dog (Still-face). Finally, the experimenter reestablished the interaction (Reunion). Our results showed a decrease in affiliative behaviors in dogs during the Still-face phase according to changes in the human's behavior, a pattern similar to the one previously found in infants. Contrary to expectations, no stress-related behaviors were shown during that phase. A carry-over effect was also observed in the Reunion phase. This study provides information about the human-dog interaction and the effects of its disruption on dogs' behaviors.

Effects of oxytocin administration and the dog-owner bond on dogs' rescue behavior.

Rescue behavior is a kind of prosocial response that involves the provision of help to a stressed individual. This behavior has been observed in domestic dogs assisting their owners when they pretended to be trapped. Given the role of the hormone oxytocin as a facilitator for prosocial behavior, we aimed to evaluate the effects of its intranasal administration on the rescue behavior of dogs directed to their owners. In addition, we used the Monash Dog Owner Relationship Scale (MDORS) to assess whether the dog-owner bond was associated with this behavior. After receiving either oxytocin or saline, dogs participated in a stressed condition in which their owner pretended to be stressed inside of a box, or a control one, in which the owner was in a calm state. Dogs released their owners more frequently in the stressed condition. Contrary to our expectations, dogs who received oxytocin were less likely to open the box and took longer to do so than those that received saline. Regarding the dog-owner bond, dogs in the stressed condition who received oxytocin exhibited a lower rate and a higher latency of openings the more intense the bond was, while the opposite pattern was observed in dogs in the control condition who received saline. In conclusion, dogs would rescue their owners when they pretended to be trapped and stressed. Both oxytocin administration and the bond with the owner appear to modulate this behavior, but further studies are needed to inquire into the involved mechanisms.

Asking for help: Do dogs take into account prior experiences with people?

When confronted with a difficult or impossible problem, dogs tend to look back at humans and try to catch their attention, instead of trying to solve it themselves. This behavior has been interpreted as a help request, but it is debated whether dogs take into account prior experiences with people when selecting whom to turn to. In the present study, dogs were trained to discriminate between a generous experimenter who gave them food and a selfish one that took it away. After assessing that they had established a preference for the generous one, we exposed them to an unsolvable task in which food was locked inside a container, while the experimenters stood on each side of the apparatus. During this task, we measured their behaviors towards each experimenter. Results showed that dogs did not first turn to the generous experimenter. However, they gazed more at the generous experimenter during the task, which implies that they did, to some degree, selectively ask for help based on previous interactions. Moreover, they gazed more and spent significantly more time in contact with the female experimenter when she was generous, suggesting a possible synergic effect of the experimenters' ID (male/female) and their attitude (generous/selfish). All in all, these results suggest that, to some extent, dogs are able to use the information from previous interactions with unknown humans to selectively ask for help.

Do dogs rescue their owners from a stressful situation? A behavioral and physiological assessment.

Rescue behavior is considered a type of pro-social response, defined as a voluntary action directed to benefit another individual who is in a stressful or dangerous situation. In two experiments, we investigated whether dogs would rescue their owners when the person was trapped inside a wooden box and emitted clear signs of stress. The performance of these dogs was compared against that of a control group in which the owners remained calm while trapped. In addition, to assess if training modulated this behavior, we tested a group of dogs from the military trained in search and rescue tasks (Experiment 1). Results showed that dogs opened the box more frequently when the owner pretended to be stressed than when calm. Training shortened latencies to open the door but not the frequency of the behavior. In Experiment 2, we investigated if emotional contagion could be a possible mechanism underlying dogs' rescue responses by measuring dogs' behavior, heart rate, and saliva cortisol level in the stressed and calm conditions, and also controlled for obedience by having the calm owners call their pets while trapped. We replicated the findings of Experiment 1 as more dogs opened the door in the stressed owner condition than in the calm condition. In addition, we observed an increase in heart rate across trials in the stressed condition and a decrease across trials in the calm condition, but no differences in cortisol levels or stress-related behaviors between conditions. In brief, we found evidence that approximately half of the dogs without previous training showed spontaneous rescue behaviors directed to their owners. Neither was this behavior motivated by obedience nor by the motivation to re-establish social contact with the owner. We conclude that emotional contagion is a plausible mechanism underlying dogs' rescue behavior in the present protocol.

Training improves inhibitory control in water rescue dogs.

Inhibitory control is a collection of several processes that are aimed to refrain from any impulsive response in the subject during inappropriate situations. Evidence suggests that in dogs, the inhibitory control is affected by domestication process, but also experiences during ontogeny could be an important driver in acquiring inhibitory control. The aim of the study was to compare the performance of highly trained dogs (i.e., water rescue dogs) and pet dogs in the A-not-B task. In this procedure, the animals have to inhibit their urge of going to a previous reinforced place. The results showed that the trained dogs committed fewer errors in the task than the pet dogs suggesting a better inhibitory control. This result could indicate that inhibitory control is a flexible ability affected by ontogenetic processes such as the training experience.

Effect of Intranasal Oxytocin Administration on Human-Directed Social Behaviors in Shelter and Pet Dogs.

A wide variety of evidence has demonstrated that oxytocin is involved in socio-cognitive skills in domestic dogs (Canis familiaris). The purpose was to evaluate the effect of oxytocin administration on socio-cognitive abilities in two populations of dogs with different levels of daily human contact: shelter and pet dogs. Additionally, the effect of different doses of oxytocin (i.e., 16 and 24 IU) was assessed. To this end, dogs were tested on two tasks: a sociability test to assess their social responses and a communicative task focused on the learning of gazing responses. Results showed that pet dogs performed better than shelter dogs on the sociability and the gazing tests showing the relevance of dogs' previous experience and learning when interacting with people. The administration of 16 IU as well as 24 IU of oxytocin improved the performance on the communicative learning task, producing an increment in gaze duration during extinction. This difference was observed in both pet and shelter dogs. Therefore, oxytocin seems to participate in the persistence of this communicative response. However, the treatment did not modify the behaviors during the sociability test. Furthermore, oxytocin appears to be beneficial to increase the communicative abilities of shelter dogs.

La importancia de la oxitocina en el vínculo entre perros y personas / The relevance of oxytocin in the dog-human bond

Dadas las crecientes investigaciones acerca de las habilidades sociocognitivas de los perros domésticos, recientemente se renovó el interés hacia sus correlatos fisiológicos. Particularmente se está indagando en el papel de la oxitocina (OT), una neurohormona que modula las conductas afiliativas y sociocognitivas de diversas especies. El objetivo del presente trabajo es realizar una revisión de los estudios sobre los efectos de la OT en las conductas sociocognitivas en perros. Se analizarán los trabajos que miden OT endógena y los efectos de la administración exógena. Asimismo, se presentarán las posibles áreas de aplicación, así como la dirección de futuras investigaciones en el área.

Given the growing investigation on the dog-human bond and sociocognitive skills of domestic dogs, the focus of research has recently been shifted towards its physiological correlates. Oxytocin (OT), a neuro-hormone that modulates affiliative and sociocognitive behaviors in a wide number of species, has received particular interest. The aim of this paper is to review studies which focus on the effects of OT on the socio-cognitive behaviors in dogs. These works were divided into investigations that measured endogenous and exogenous administration of OT. Several endogenous OT studies measure OT concentration in dogs using samples of blood, urine or saliva. In these studies, OT effects on affiliative interactions, mutual gazing and stressful situations were found. Physical contact and gazing were affiliative interactions which modulated the OT release. In addition, proximity and contact seeking were associated with OT release in stressful situations. Exogenous OT studies measure the physiological and behavioral effects of OT intranasal administration. These studies were grouped into research that found effects of OT in social interaction, gaze, communication, and cognitive bias in dogs. In the social interaction studies, intranasal OT was found to improve affiliative behaviors with both interspecifics and conspecifics. In gazing studies, this neuro-hormone was found to increase gazing towards the region of human eyes, even in threatening contexts. Regarding communicative effects, OT modulated the ability to follow human communicative cues in dogs. Moreover, was found that OT increased positive cognitive bias and induced positive expectations. Although there is evidence of OT influencing behavior on both sexes, some studies have found differences based on gender. For example, the females had longer gaze duration toward humans, improved following of human communicative cues such as pointing and looked more at projected images on a screen than males. These effects could be explained by the interaction of the OT system and the estrogen levels in females. Concerning the applied area, OT could beused in the treatment of canine behavioral problems such as social deficits, phobias and separation anxiety. Moreover, it could facilitate integration in dogs with poor early socialization, like shelter or abandoned dogs. In addition, it could improve the training in rescue and assistance dogs. However, further research is needed since there are no follow-up reports of treatments in dogs. In conclusion, OT increases affiliative behaviors in dogs both towards humans and their conspecifics. Regarding endogenous OT studies, effects were found with both brief interactions ranging between 3 and 4 minutes, as well as long-term interactions, between 25 and 30 minutes. In exogenous OT studies, although there is no consensus on the amounts of OT to be administered, effects were found with 2 IU / kg,12, 24 and 40 IU on at least one of the measured variables. Specifically, nasal OT enhances the ability to use human communicative cues, induces positive expectations about neutral stimuli, and increases gaze both toward human eyes and to socially relevant stimuli. A number of exogenous OT studies showed differential effects on sex. Female dogs had greater responses to exogenous OT administration than males. Therefore, sex should be a variable to be considered in future studies. In sum, although the studies in this field are incipient, OT appears to be key in the interaction between dogs and humans since it participates in the interspecific bond, affiliative behaviors and socio-cognitive skills in domestic dogs.

Dogs' recognition of human selfish and generous attitudes requires little but critical experience with people.

There is some dispute regarding the role of experience in the development of dogs´ socio-cognitive abilities in their interaction with people. We sought to provide new evidence to this debate by comparing dogs with contrasting levels of experience with humans, in a task involving the discrimination of human generous and selfish attitudes. To this end, we compared the performance of adult family dogs against that of adult shelter dogs and puppies living in people´s homes. In training trials, the generous experimenter (G) signaled the bowl with food and allowed the dog to eat, whereas the selfish experimenter (S) also signaled the baited bowl, but she/he ate the food before the dog could have access to it. Then, subjects were allowed to freely choose between G and S in the choice test. The main finding was that adult subjects (both family and shelter dogs) developed a preference for G over S, but puppies did not. We conclude that the quality and/or quantity of everyday-contact with people did not affect the discrimination of human attitudes in the present protocol, but the amount of experience with people (in years) did matter. Finally, we discuss the relative role of domestication and ontogeny in the development of dogs´ socio-cognitive abilities.

Direct reciprocity in animals: The roles of bonding and affective processes.

The presence of direct reciprocity in animals is a debated topic, because, despite its evolutionary plausibility, it is believed to be uncommon. Some authors claim that stable reciprocal exchanges require sophisticated cognition which has acted as a constraint on its evolution across species. In contrast, a more recent trend of research has focused on the possibility that direct reciprocity occurs within long-term bonds and relies on simple as well as more complex affective mechanisms such as emotional book-keeping, rudimentary and higher forms of empathy, and inequity aversion, among others. First, we present evidence supporting the occurrence of long-term reciprocity in the context of existing bonds in social birds and mammals. Second, we discuss the evidence for affective responses which, modulated by bonding, may underlie altruistic behaviours in different species. We conclude that the mechanisms that may underlie reciprocal exchanges are diverse, and that some act in interaction with bonding processes. From simple associative learning in social contexts, through emotional contagion and behavioural mimicry, to empathy and a sense of fairness, widespread and diverse social affective mechanisms may explain why direct reciprocity may not be a rare phenomenon among social vertebrates.

Following human pointing: Where do dogs (Canis familiaris) look at to find food?

Domestic dogs (Canis familiaris) are notably skillful in following cues from people (e.g., pointing gestures). However, not much is known about the processing of information available during such tasks. We here focus on one of the earliest of such processes, namely attention. The goal of the present work was to describe variations in dogs' attention towards diverse targets while they solve an object choice task with human pointing. The direction of subjects' gaze was measured in the period comprising one second before and two seconds after the experimenter called the dog and simultaneously performed a static distal pointing gesture towards the correct bowl. We did two consecutive training phases: acquisition and extinction. Dogs spent more time watching the pointer than the pointing gesture itself and the correct than the incorrect bowl. Indeed, the time spent watching the correct bowl was the best predictor of correct choices across phases. We discuss the relevance of these findings for the process of local enhancement.

Sociability and gazing toward humans in dogs and wolves: Simple behaviors with broad implications.

Sociability, defined as the tendency to approach and interact with unfamiliar people, has been found to modulate some communicative responses in domestic dogs, including gaze behavior toward the human face. The objective of this study was to compare sociability and gaze behavior in pet domestic dogs and in human-socialized captive wolves in order to identify the relative influence of domestication and learning in the development of the dog-human bond. In Experiment 1, we assessed the approach behavior and social tendencies of dogs and wolves to a familiar and an unfamiliar person. In Experiment 2, we compared the animal's duration of gaze toward a person's face in the presence of food, which the animals could see but not access. Dogs showed higher levels of interspecific sociability than wolves in all conditions, including those where attention was unavailable. In addition, dogs gazed longer at the person's face than wolves in the presence of out-of-reach food. The potential contributions of domestication, associative learning, and experiences during ontogeny to prosocial behavior toward humans are discussed.

Interspecific social skills in a highly socialized Aguará Guazú (maned wolf, Chrysocyon brachyurus). A pilot-subject study

Some beliefs seem to be more resilient to change and extinction than others. This paper argues that some of the strong beliefs held by humans have deep biological roots in our evolutionary past, and the neuronal pathways and structures that support them can be found in other species. This paper describes four basic universal criteria present in persistent beliefs: intuitibility, predictability, reliability and utility (IPRU). The paper argues that the study of belief as a modern scientific discipline will require consideration of the evolutionary context through which the neural pathways associated with belief formation, maintenance and endorsement have emerged. We also suggest that the study of religious belief has discouraged the adoption of an overarching framework for understanding our belief system in all its breadth. Our approach incorporates evolution-driven cognitive and affective biases, attachment mechanisms and reward expectation. Rather than operating as genuinely adaptive phenomena associated with evolutionary advantage, we suggest that belief systems emerge as a by-product of evolutionary pressures

Há crenças que parecem ser mais resilientes a mudanças e extinção do que outras. Este artigo argumenta que algumas das crenças humanas mais fortes têm raízes biológicas profundas em nosso passado evolutivo, e que vias e estruturas nervosas que as suportam podem ser encontradas em outra espécie. Este trabalho descreve quatro critérios universais básicos nas crenças persistentes: ser intuitiva, ser previsível, ser confiável e ser utilizável (IPRU). O trabalho argumenta que o estudo de crença como uma disciplina moderna demandará considerações sobre o contexto evolutivo, através do qual emergiram vias neurais associadas à formação, manutenção e apoio à crença. Também é sugerido que o estudo da crença religiosa tem desencorajado a adoção de um contexto abrangente para a compreensão de nosso sistema de crença em toda a sua profundidade. Abordagem aqui utilizada incorpora viés cognitivo movido pela evolução assim como viés afetivo, mecanismos de fixação e expectativas de recompensa. Sugerimos que os sistemas de crença emergiram como subproduto de pressões evolutivas, ao invés de operar como um processo genuinamente adaptativo associado a vantagens evolutivas

Dog's discrimination of human selfish and generous attitudes: the role of individual recognition, experience, and experimenters' gender.

Discrimination of and memory for others' generous and selfish behaviors could be adaptive abilities in social animals. Dogs have seemingly expressed such skills in both direct and indirect interactions with humans. However, recent studies suggest that their capacity may rely on cues other than people's individual characteristics, such as the place where the person stands. Thus, the conditions under which dogs recognize individual humans when solving cooperative tasks still remains unclear. With the aim of contributing to this problem, we made dogs interact with two human experimenters, one generous (pointed towards the food, gave ostensive cues, and allowed the dog to eat it) and the other selfish (pointed towards the food, but ate it before the dog could have it). Then subjects could choose between them (studies 1-3). In study 1, dogs took several training trials to learn the discrimination between the generous and the selfish experimenters when both were of the same gender. In study 2, the discrimination was learned faster when the experimenters were of different gender as evidenced both by dogs' latencies to approach the bowl in training trials as well as by their choices in preference tests. Nevertheless, dogs did not get confused by gender when the experimenters were changed in between the training and the choice phase in study 3. We conclude that dogs spontaneously used human gender as a cue to discriminate between more and less cooperative experimenters. They also relied on some other personal feature which let them avoid being confused by gender when demonstrators were changed. We discuss these results in terms of dogs' ability to recognize individuals and the potential advantage of this skill for their lives in human environments.

Individual differences in social and non-social behaviors in domestic dogs (Canis familiaris) during the acquisition, extinction and reacquisition of a problem solving task.

Dogs are able to solve different problems by trial and error learning, but it seems that they cannot understand the means-end connection. Some studies suggest that dogs' performance is influenced by their breed and by the level of familiarity with the person they interact with. In our study, we assess individual differences in both social and non-social responses in a problem-solving task during the acquisition, extinction, and reacquisition phases. In order to investigate the effect of familiarity, in the first experiment, the human present during the task was either a familiar (the dog's owner) or unfamiliar person. In the second experiment, we compared breeds (Retrievers and Shepherds) that had previously shown differences in a communicative task. The results revealed that all groups learned the task and became more efficient in the acquisition trials. These non-social responses diminished during extinction, where an increase in social responses was observed. With regard to individual differences, dogs were more persistent in searching the reward during the second extinction trial when the owner was present (in contrast with a stranger), and also looked longer at the unfamiliar person at the beginning of the acquisition trial. On the other hand, Retrievers showed greater social motivation during reacquisition and Shepherds picked up more bones during the third acquisition trial, thus suggesting a more persistent search of the reward. These findings highlight the relevance of studying different learning schedules as well as individual differences in problem-solving ability so as to improve selection and training techniques.

Estudios Sobre Cooperación en Perros Domésticos: una Revisión Crítica / Studies on Cooperation in Household Dogs: A Critical Review / Estudos sobre Cooperação em Cachorros Domésticos: uma Revisão Crítica

El análisis comparado de la cooperación contribuye al entendimiento tanto de sus orígenes evolutivos como de los mecanismos próximos involucrados en dicho fenómeno. Esta revisión se centra en estudios sobre cooperación en perros domésticos. Para ello se definieron conceptos relacionados con la cooperación, se describieron las razones filogenéticas y ontogenéticas que hacen del perro un buen modelo para el estudio de este fenómeno y se hizo una revisión crítica de los trabajos realizados en este campo. Fueron incluidas investigaciones sobre situaciones cooperativas y sobre las habilidades cognitivas involucradas. Se discuten hipótesis sobre los mecanismos próximos de esta habilidad que incluyen elementos emocionales, motivacionales y de aprendizaje asociativo.

The comparative analysis of cooperation contributes to the understanding of both its evolutionary origins and the proximate mechanisms involved in this phenomenon. This review focuses on studies of cooperation in household dogs, describing the phylogenetic and ontogenetic reasons that make dogs a good model for the study of this phenomenon, and carrying out a critical review of the research carried out in this field, particularly of research regarding cooperative situations and the cognitive abilities involved. The article also discusses hypotheses regarding the proximate mechanisms of this ability, which include emotional, motivational, and associative learning abilities.

A análise comparada da cooperação contribui para o entendimento tanto de suas origens evolutivas quanto dos mecanismos próximos envolvidos nesse fenômeno. Esta revisão se centraliza em estudos sobre cooperação em cachorros domésticos. Para isso, definiram-se conceitos relacionados com a cooperação, descreveram-se as razões filogenéticas e ontogenéticas que fazem do cachorro um bom modelo para o estudo desse fenômeno e fez-se uma revisão crítica dos trabalhos realizados nesse campo. Foram incluídas pesquisas sobre situações cooperativas e sobre as habilidades cognitivas envolvidas. Discutem-se hipóteses sobre os mecanismos próximos dessa habilidade que incluem elementos emocionais, motivacionais e de aprendizagem associativa.

¿Pueden los perros domésticos (Canis lupus familiaris) reconocer expresiones emocionales humanas? Una revisión crítica de las evidencias

Las expresiones emocionales tienen un papel fundamental en las interacciones de especies sociales, brindando información acerca del emisor, las características e importancia del estímulo o situación que desencadena tales interacciones, y también funcionan regulando los vínculos sociales. Los perros poseen notorias capacidades comunicativas hacia los humanos por lo que resulta interesante estudiar si estas habilidades se extienden al reconocimiento de las expresiones emocionales. Se han realizado diversas investigaciones acerca del reconocimiento de expresiones emocionales humanas en perros exponiéndolos a una situación representada por personas durante la evaluación, así como mediante el uso de imágenes, videos y grabaciones. El análisis de las evidencias permite concluir que los perros podrían distinguir entre distintas emociones humanas ya sea en presencia de modelos en vivo o mediante la observación de imágenes y modulan su conducta conforme esta discriminación, así como también pueden utilizar esta información como clave en la resolución de problemas. Sin embargo, aún no están claros los mecanismos que subyacen a estas habilidades.(AU)

Emotional expressions play a critical role in the interactions among individuals, particularly, in social species. They provide information about the sender and the characteristics and importance of the triggering stimulus or situation, also regulating social ties. Dogs have notorious communication skills towards humans, which makes the study of their ability to recognize human emotional expressions an interesting endeavor. There have been several studies in which dogs have been tested using real people in an experimental situation as well as images, video and audio recordings of people's expressions. The evidence suggests that dogs can discriminate between different human emotions either in the presence of live models or by looking at images. This type of information has been shown to modulate their behavior and to be used as cues to solve problems. However, the mechanisms underlying these abilities are not fully understood yet.(AU)

¿Pueden los perros domésticos (canis lupus familiaris) reconocer expresiones emocionales humanas? una revisión crítica de las evidencias / Can domestic dogs (canis lupus familiaris) recognize human emotional expressions? a critical review of the evidence

Las expresiones emocionales tienen un papel fundamental en las interacciones de especies sociales, brindando información acerca del emisor, las características e importancia del estímulo o situación que desencadena tales interacciones, y también funcionan regulando los vínculos sociales. Los perros poseen notorias capacidades comunicativas hacia los humanos por lo que resulta interesante estudiar si estas habilidades se extienden al reconocimiento de las expresiones emocionales. Se han realizado diversas investigaciones acerca del reconocimiento de expresiones emocionales humanas en perros exponiéndolos a una situación representada por personas durante la evaluación, así como mediante el uso de imágenes, videos y grabaciones. El análisis de las evidencias permite concluir que los perros podrían distinguir entre distintas emociones humanas ya sea en presencia de modelos en vivo o mediante la observación de imágenes y modulan su conducta conforme esta discriminación, así como también pueden utilizar esta información como clave en la resolución de problemas. Sin embargo, aún no están claros los mecanismos que subyacen a estas habilidades.

Emotional expressions play a critical role in the interactions among individuals, particularly, in social species. They provide information about the sender and the characteristics and importance of the triggering stimulus or situation, also regulating social ties. Dogs have notorious communication skills towards humans, which makes the study of their ability to recognize human emotional expressions an interesting endeavor. There have been several studies in which dogs have been tested using real people in an experimental situation as well as images, video and audio recordings of people's expressions. The evidence suggests that dogs can discriminate between different human emotions either in the presence of live models or by looking at images. This type of information has been shown to modulate their behavior and to be used as cues to solve problems. However, the mechanisms underlying these abilities are not fully understood yet.

Evaluación del temperamento en perros de refugio y de familia. Un estudio comparativo / Avaliação do temperamento em cães de refúgio e de família. Um estudo comparativo / Evaluation of the temperament of shelter dogs and family pets. A comparative study

Este estudio comparó el desempeño de perros de refugio y de familia en una batería de pruebas comportamentales de temperamento, con el fin de evaluar si existe una asociación entre las condiciones de alojamiento en refugios (restricción social y espacial) y la aparición de alteraciones del comportamiento. Se utilizaron 30 perros domésticos mestizos a los que se les administró una batería de cuatro pruebas de temperamento: sociabilidad y miedo interespecífico, entrenabilidad, agresión interespecífica y miedo no social. Los resultados muestran que, comparados con los perros de familia, los perros de refugio permanecieron más tiempo cerca de la experimentadora en la prueba de sociabilidad y presentaron puntuaciones significativamente más elevadas en la prueba de miedo no-social.

The study compared the performance of shelter dogs and family pets in a battery of behavioral temperament tests, in order to evaluate whether there is an association between the living conditions in shelters (social and spatial restriction) and alterations of behavior. Thirty half-breed house dogs were given a battery of four temperament tests: sociability and interspecific fear, trainability, interspecific aggression, and non-social fear. Results show that, compared to family pets, shelter dogs remained close to the experimenter for a longer period during the sociability test and their scores were significantly higher in the non-social fear test.

Este estudo comparou o desempenho de cães de refúgio e de família em uma série de provas comportamentais de temperamento, com o objetivo de avaliar se existe uma associação entre as condições de alojamento em refúgios (restrição social e espacial) e o surgimento de alterações do comportamento. Utilizaram-se 30 cães domésticos mestiços aos quais foram dadas quatro provas de temperamento: sociabilidade e medo interespecífico, treinabilidade, agressão interespecífica e medo não social. Os resultados mostram que, comparados com os cães de família, os de refúgio permaneceram mais tempo perto da experimentadora na prova de sociabilidade e apresentaram pontuações significativamente mais elevadas nas provas de medo não social.

Dogs' Eavesdropping from people's reactions in third party interactions.

Eavesdropping involves the acquisition of information from third-party interactions, and can serve to indirectly attribute reputation to individuals. There is evidence on eavesdropping in dogs, indicating that they can develop a preference for people based on their cooperativeness towards others. In this study, we tested dogs' eavesdropping abilities one step further. In a first experiment, dogs could choose between cooperative demonstrators (the donors) who always gave food to an approaching third person (the beggar); here, the only difference between donors was whether they received positive or negative reactions from the beggar (through verbal and gestural means). Results showed that dogs preferentially approached the donor who had received positive reactions from the beggar. By contrast, two different conditions showed that neither the beggar's body gestures nor the verbal component of the interaction on their own were sufficient to affect the dogs' preferences. We also ran two further experiments to test for the possibility of dogs' choices being driven by local enhancement. When the donors switched places before the choice, dogs chose at random. Similarly, in a nonsocial condition in which donors were replaced by platforms, subjects chose at chance levels. We conclude that dogs' nonrandom choices in the present protocol relied on the simultaneous presence of multiple cues, such as the place where donors stood and several features of the beggar's behavior (gestural and verbal reactions, and eating behavior). Nonetheless, we did not find conclusive evidence that dogs discriminated the donors by their physical features, which is a prerequisite of reputation attribution.

Frustration behaviors in domestic dogs.

During extinction a previously learned behavior stops being reinforced. In addition to the decrease in the rate of the instrumental response, it produces an aversive emotional state known as frustration. This state can be assimilated with the fear reactions that occur after aversive stimuli are introduced at both the physiological and behavioral levels. This study evaluated frustration reactions of domestic dogs (Canis familiaris) during a communicative situation involving interactions with a human. The task included the reinforcement and extinction of the gaze response toward the experimenter's face when the dogs tried to obtain inaccessible food. The dog's frustration reactions during extinction involved an increase in withdrawal and side orientation to the location of the human as well as lying down, ambulation, sniffing, and vocalizations compared with the last acquisition trial. These results are especially relevant for domestic dog training situations in which the extinction technique is commonly used to discourage undesirable behaviors.