Human Social Cues Research Articles

The ontogeny of human point following in dogs: When younger dogs outperform older

We investigated puppies’ responsiveness to hand points differing in salience. Experiment 1 compared performance of younger (8 weeks old) and older (12 weeks) shelter pups in following pointing gestures. We hypothesized that older puppies would show better performance. Both groups followed the easy and moderate but not the difficult pointing cues. Surprisingly, the younger pups outperformed the older ones in following the moderate and difficult points. Investigation of subjects’ backgrounds revealed that significantly more younger pups had experience living in human homes than did the older pups. Thus, we conducted a second experiment to isolate the variable experience. We collected additional data from older pet pups living in human homes on the same three point types and compared their performance with the shelter pups from Experiment 1. The pups living in homes accurately followed all three pointing cues. When comparing both experienced groups, the older pet pups outperformed the younger shelter ones, as predicted. When comparing the two same-age groups differing in background experience, the pups living in homes outperformed the shelter pups. A significant correlation between experience with humans and success in following less salient cues was found. The importance of ontogenetic learning in puppies' responsiveness to certain human social cues is discussed.

Oxytocin enhances the appropriate use of human social cues by the domestic dog (Canis familiaris) in an object choice task

It has been postulated that the neuropeptide, oxytocin, is involved in human-dog bonding. This may explain why dogs, compared to wolves, are such good performers on object choice tasks, which test their ability to attend to, and use, human social cues in order to find hidden food treats. The objective of this study was to investigate the effect of intranasal oxytocin administration, which is known to increase social cognition in humans, on domestic dogs' ability to perform such a task. We hypothesised that dogs would perform better on the task after an intranasal treatment of oxytocin. Sixty-two (31 males and 31 females) pet dogs completed the experiment over two different testing sessions, 5-15 days apart. Intranasal oxytocin or a saline control was administered 45 min before each session. All dogs received both treatments in a pseudo-randomised, counterbalanced order. Data were collected as scores out of ten for each of the four blocks of trials in each session. Two blocks of trials were conducted using a momentary distal pointing cue and two using a gazing cue, given by the experimenter. Oxytocin enhanced performance using momentary distal pointing cues, and this enhanced level of performance was maintained over 5-15 days time in the absence of oxytocin. Oxytocin also decreased aversion to gazing cues, in that performance was below chance levels after saline administration but at chance levels after oxytocin administration.

A comparison of pet and purpose-bred research dog (Canis familiaris) performance on human-guided object-choice tasks

Several studies have shown that domestic dogs respond to human social cues such as pointing. Some experiments have shown that pet dogs outperformed wolves in following a momentary distal point. These findings have lent support to the hypothesis that domestication is responsible for domestic dogs’ ability to utilize human gestures. Other studies demonstrating comparable performance in human-socialized wolves suggest this skill depends on experience with relevant human stimuli. However, domestic dogs lacking thorough exposure to humans are underrepresented in the comparative literature. The goal of this study was to evaluate pet and kennel-reared research domestic dogs on their ability to follow two types of point in an object-choice task. This study used young adult, intact male research dogs (n=11) and a comparison group of pet dogs living in human homes (n=9). We found that while pet dogs followed the momentary distal point above chance levels, research dogs did not. Both groups followed the simpler dynamic proximal point; however, pet dogs outperformed research dogs on this task. Our results indicate that ontogenetic experiences may influence a domestic dog's ability to use human gestures, highlighting the importance of testing different sub-populations of domestic dogs.

Testing the Cognition of the Forgotten Colobines: A First Look at Golden Snub-Nosed Monkeys (Rhinopithecus roxellana)

Although our understanding of primate cognition is growing rapidly, little is known about the cognition of colobines. Here we report the results of a set of 5 experiments on colobine cognition using 17 golden snub-nosed monkeys (Rhinopithecus roxellana). These monkeys are folivores that form multilevel societies with groups of hundreds of individuals and relatively high fission–fusion dynamics. We investigated their sensitivity to human social cues and ability to inhibit impulsive behavioral responses. In three sociocognitive experiments we found that, like most other primates, they follow the gaze direction of a human demonstrator but there is no evidence that they use others’ social cues in a cooperative task to locate hidden food or in a competitive task to steal forbidden food. In two inhibitory control experiments, we found that the monkeys showed a low level of inhibitory control, comparable to that of other folivorous primates. These results suggest that phylogeny and folivory might have been important in shaping the cognition of golden snub-nosed monkeys. Moreover, this species’ large group size and relatively high fission–fusion dynamics may not have imposed a significant social challenge to their cognition, as social interactions occur mainly within basic social units.

African Elephants Can Use Human Pointing Cues to Find Hidden Food

How animals gain information from attending to the behavior of others has been widely studied, driven partly by the importance of referential pointing in human cognitive development [1-4], but species differences in reading human social cues remain unexplained. One explanation is that this capacity evolved during domestication [5, 6], but it may be that only those animals able to interpret human-like social cues were successfully domesticated. Elephants are a critical taxon for this question: despite their longstanding use by humans, they have never been domesticated [7]. Here we show that a group of 11 captive African elephants, seven of them significantly as individuals, could interpret human pointing to find hidden food. We suggest that success was not due to prior training or extensive learning opportunities. Elephants successfully interpreted pointing when the experimenter's proximity to the hiding place was varied and when the ostensive pointing gesture was visually subtle, suggesting that they understood the experimenter's communicative intent. The elephant's native ability in interpreting social cues may have contributed to its long history of effective use by man.

Contagious yawning, social cognition, and arousal: an investigation of the processes underlying shelter dogs’ responses to human yawns

Studies of contagious yawning have reported inconsistent findings regarding whether dogs exhibit this behavior and whether it is mediated by social-cognitive processes or the result of physiological arousal. We investigated why some dogs yawn in response to human yawns; particularly, whether these dogs are exceptional in their ability to understand human social cues or whether they were more physiologically aroused. Sixty shelter dogs were exposed to yawning and nonyawning control stimuli demonstrated by an unfamiliar human. We took salivary cortisol samples before and after testing to determine the role of arousal in yawn contagion. Dogs were tested on the object-choice task to assess their sensitivity for interpreting human social cues. We found that 12 dogs yawned only in response to human yawns (i.e., appeared to exhibit yawn contagion), though contagious yawning at the population level was not observed. Dogs that exhibited yawn contagion did not perform better on the object-choice task than other dogs, but their cortisol levels remained elevated after exposure to human yawning, whereas other dogs had reduced cortisol levels following yawning stimuli relative to their baseline levels. We interpret these findings as showing that human yawning, when presented in a stressful context, can further influence arousal in dogs, which then causes some to yawn. Although the precise social-cognitive mechanisms that underlie contagious yawning in dogs are still unclear, yawning between humans and dogs may involve some communicative function that is modulated by context and arousal.

Pointing gestures modulate domestic dogs’ search behavior for hidden objects in a spatial rotation problem

In the spatial domain, domestic dogs are highly inclined to search at the last location where they saw an object disappear and cannot infer that a hidden object has moved imperceptibly from one location to another. In the current study, we examined whether exposure to human social cues modulates dogs’ search behavior for hidden objects. In Experiment 1, twenty dogs were first trained to find an object they saw disappear inside a stationary container in the presence (social group) or absence (non-social group) of pointing gestures. In tests, the containers were rotated 180° around a central axis. The dogs in the non-social group systematically searched at the initial (now incorrect) hiding location, whereas the dogs in the social group chose correctly significantly above chance. In Experiment 2, we tested whether pre-exposure to human pointing has an impact on dogs’ use of gestures. No gestures were given during training and both the social and non-social conditions were administered to each of the ten dogs. In contrast to Experiment 1, the performance of dogs in the social condition dropped significantly and varied substantially from one dog to another. Overall, this study suggests that dogs’ tendency to use human signals is so strong that it even outweighs their spatial bias to search where they saw an object disappear; however, this penchant to use human gestures appears to be dependent on the degree of familiarity of the dog with these signals.

Human disturbance and conspecifics influence display site selection by Great Bustards Otis tarda

SummaryUnderstanding habitat selection and assessing habitat quality have an important role in habitat management and prioritisation of areas for protection. However, interpretations of habitat selection and habitat quality can be confounded by social effects such as conspecific attraction. Using 7 years’ data from a well monitored Great Bustard Otis tarda population in Central Europe, we investigated the roles of human disturbance and social cues in display site selection of male Great Bustards Otis tarda. The spatial distribution of displaying males was best predicted by human disturbance. In addition, the number of males attending display sites was strongly correlated to the number of females present and not with disturbance. This suggests that abundance could be a misleading metric for habitat quality in social species. Our results highlight the roles of disturbance and social cues in male habitat choice, and suggest that social factors need to be taken into consideration for management of endangered populations.

Advanced Human Behavioral Cues Detection: A Method in Social Signal Processing

Social Signal Processing (SSP) is the new research domain that aims at understanding social interactions and social intelligence. The essence of social intelligence is the ability to recognize human social signals and behaviors cues (verbal and non-verbal). We present a unified model for non-verbal behavioral cues SSP under the categories of face detection like eyes-mouth-lips-ears-nose, emotional assessments like anger-happy-sadness-neutral and physical appearance like height (short-average-tall), attractiveness (smartness) and body shape(slim-normal-flat) in real-world cluttered images which is one of the method in social signal processing. It is rather difficult task to detect and interpret temporal patterns of nonverbal behavioral cues in a given context. Our main objective is to detect non-verbal behavioral cues by introducing advanced human behavioral cues detection method. Our proposed method shown a better results and practically applicable in the real world environment. We implemented our proposed method in MATLAB R2007b simulator and designed a GUI for our proposed method .

Responder de Cães por Exclusão em Tarefas de Discriminação Condicional

O presente estudo treinou o responder por exclusão em cães por meio do ensino de discriminações condicionais entre objetos e seus respectivos nomes ditados e avaliou empiricamente a influência neste desempenho de dicas sociais humanas (gestos direcionados aos estímulos) quando estas eram direcionadas ao estímulo contrário. Os dois animais demonstraram rápida aquisição de controle pelo estímulo novo, controle que se manteve mesmo com a inserção de dicas sociais contrárias ao estímulo ditado (instruir oralmente a seleção de S+, porém apontar para S-). Foi evidente a influência das dicas sociais contrárias quando os estímulos eram familiares, com ruptura do controle preestabelecido. Discute-se a relevância deste estudo na comparação de diferentes aspectos do ambiente no comportamento canino, e enfatiza-se a necessidade de incluir sondas de controle pela novidade, para pesquisas futuras. Palavras-chave: exclusão; aprendizagem animal; discriminação condicional; cães.

Pointing following in dogs: are simple or complex cognitive mechanisms involved?

Domestic dogs have proved to be extremely successful in finding hidden food following a series of human social cues such as pointing (an extended hand and index finger indicating the location of the reward), or body position, among many other variants. There is controversy about the mechanisms responsible for these communicative skills in dogs. On the one hand, a hypothesis states that dogs have complex cognitive processes such as a theory of mind, which allow them to attribute intent to the human pointing gesture. A second, more parsimonious, hypothesis proposes that these skills depend on associative learning processes. The purpose of this paper is to provide data that may shed some light on the discussion by looking into two learning processes by using an object choice task: the effect of interference between stimuli on the preference for human social cues and the effect of generalization of the response to novel human social stimuli. The first study revealed that previous training using a physical cue (container location) may hamper the learning of a novel human social cue (distal cross-pointing). The results of the second study indicated stimulus generalization. Dogs learnt a novel cue (distal cross-pointing) faster due to previous experience with a similar cue (proximal pointing), as compared to dogs confronted by a less similar cue (body position) or dogs with no previous experience. In sum, these findings support the hypothesis about the important role of associative learning in interspecific communication mechanisms of domestic dogs.

Reduced recruitment of orbitofrontal cortex to human social chemosensory cues in social anxiety

Social anxiety refers to the prevalent and debilitating experience of fear and anxiety of being scrutinized in social situations. It originates from both learned (e.g. adverse social conditioning) and innate (e.g. shyness) factors. Research on social anxiety has traditionally focused on negative emotions induced by visual and auditory social cues in socially anxious clinical populations, and posits a dysfunctional orbitofrontal-amygdala circuit as a primary etiological mechanism. Yet as a trait, social anxiety is independent of one's specific emotional state. Here we probe the neural substrate of intrinsic social anxiety by employing a unique type of social stimuli, airborne human social chemosensory cues that are inherently social, ubiquitously present, and yet operating below verbal awareness. We show that the adopted social chemosensory cues were not perceived to be human-related, did not differentially bias self-report of anxiety or autonomic nervous system responses, yet individuals with elevated social anxiety demonstrated a reduced recruitment of the orbitofrontal cortex to social chemosensory cues. No reciprocal activity in the amygdala was observed. Our findings point to an intrinsic neural substrate underlying social anxiety that is not associated with prior adverse social conditioning, thereby providing the first neural evidence for the inherent social aspect of this enigmatic phenomenon.

Are dogs (Canis familiaris) misled more by their owners than by strangers in a food choice task?

Dogs are highly skilled in understanding a large variety of human social cues and use them appropriately to solve a number of different cognitive tasks. They rely on human signals even when these are contradictory or misleading and ultimately prevent them from correctly solving a task. In the following two experiments, we investigated whether the owner and a stranger differently influenced dogs' choices in food discrimination tasks. In Experiment 1, 48 dogs were tested in 3 different conditions: (1) choice between a large and a small amount of dog pellets with no demonstration; (2) choice between a large and a small amount of dog pellets after having witnessed the owner/stranger favouring the small quantity; (3) choice between two single food pellets after observing the owner/stranger choosing one of them. In Experiment 2, 48 dogs could choose between two foods of different palatability: in Condition1, dogs chose between a slice of sausage and a dry pellet with no demonstration. In Condition2, the same choice was available but with a person (owner/stranger) showing a preference for the dry pellet. In Condition3, dogs chose between a single dry pellet and 8 slices of sausage, with the person (owner/stranger) showing a preference for the pellet. In both experiments, dogs conformed to the human's indications even though these led to the selection of the less advantageous option (i.e. the smaller amount of food in Experiment 1 or the low quality food in Experiment 2). However, the owner and the stranger did not differently influence the dogs' behaviour. Results show that dogs are willing to follow a person's indication even when this is visibly (if perhaps only mildly) counterproductive to them and that they are socially prepared to rely equally on cues given by the owner and an unfamiliar friendly person.

Domesticated dogs ( Canis familiaris) react to what others can and cannot hear

Recent research suggests some nonhuman primates (e.g., chimpanzees, rhesus macaques) consider what others hear when acting in competitive situations. We explored whether dogs living in private homes or sourced from an animal shelter would show this same predilection. Following an inhibition task where dogs ( Canis familiaris) were commanded not to take a treat left on a plate by a human, we presented subjects with the opportunity to take food from one of two containers. These containers were located within the proximity of a human gatekeeper who was either looking straight ahead or not looking at the time of choice. One container was silent when food was inserted or removed while the other was noisy. Among pet dogs (20 total; 10 in each condition) randomly assigned to the Looking or Not Looking condition, four subjects approached the silent container in the Looking condition (binomial test: P = 0.8) while 10 approached the silent container in the Not Looking condition (binomial test: P = 0.004). We compared pet dogs’ pattern of performance between conditions using a chi-square test for independence, which indicated that dogs significantly preferred the silent container only in the Not Looking condition ( χ 1 2 = 8.8 , P = 0.003). This outcome suggests dogs preferentially attempted to retrieve food silently only when silence was germane to obtaining food unobserved by the human gatekeeper. Interestingly, dogs sourced from a local animal shelter evidenced similar outcomes. Among shelter dogs (20 total; 10 in each condition) randomly assigned to the Looking or Not Looking condition, four subjects approached the silent container in the Looking condition (binomial test: P = 0.8) while nine approached the silent container in the Not Looking condition (binomial test: P = 0.02). We compared shelter dogs’ pattern of performance between conditions using a chi-square test for independence, which indicated that dogs significantly preferred the silent container only in the Not Looking condition ( χ 1 2 = 5.5 , P = 0.02). This result suggests shelter dogs, like pet dogs, preferentially tried to retrieve food silently only if silence was relevant to obtaining food unobserved by a human gatekeeper. This result conflicts with other recent data suggesting that shelter dogs perform more poorly than pet dogs in tasks involving human social cues.

Virtual proximity and facial expressions of computer agents regulate human emotions and attention

AbstractEmotion‐ and attention‐related subjective and physiological responses to virtual proximity and facial expressions of embodied computer agents (ECA) were studied. Thirty participants viewed female and male characters with a neutral, unpleasant, or pleasant facial expression. Agents' size was used to simulate three levels of proximity. Participants' electrical facial muscle and heart activity were registered, and subjective ratings of emotional and attentional experiences collected. Unpleasant and large (i.e., closer) agents were more alerting (i.e., unpleasant, arousing, and dominating) and attracted more stimulus‐driven attention than neutral, pleasant, and smaller (i.e., further away) agents. Pleasant agents attracted more voluntary attention than neutral and unpleasant agents. Heart rate (HR) responded to agent proximity, while the valence of the agent affected electrical facial muscle activity. Thus, the imitation of human social emotional cues in embodied computer agents (ECAs) could be used to regulate human–computer interaction. Copyright © 2010 John Wiley & Sons, Ltd.

What did domestication do to dogs? A new account of dogs' sensitivity to human actions

Over the last two decades increasing evidence for an acute sensitivity to human gestures and attentional states in domestic dogs has led to a burgeoning of research into the social cognition of this highly familiar yet previously under-studied animal. Dogs (Canis lupus familiaris) have been shown to be more successful than their closest relative (and wild progenitor) the wolf, and than man's closest relative, the chimpanzee, on tests of sensitivity to human social cues, such as following points to a container holding hidden food. The "Domestication Hypothesis" asserts that during domestication dogs evolved an inherent sensitivity to human gestures that their non-domesticated counterparts do not share. According to this view, sensitivity to human cues is present in dogs at an early age and shows little evidence of acquisition during ontogeny. A closer look at the findings of research on canine domestication, socialization, and conditioning, brings the assumptions of this hypothesis into question. We propose the Two Stage Hypothesis, according to which the sensitivity of an individual animal to human actions depends on acceptance of humans as social companions, and conditioning to follow human limbs. This offers a more parsimonious explanation for the domestic dog's sensitivity to human gestures, without requiring the use of additional mechanisms. We outline how tests of this new hypothesis open directions for future study that offer promise of a deeper understanding of mankind's oldest companion.

Efficiency of working dogs undergoing a new Human Familiarization and Training Program

Abstract The study of human-dog interaction has increased over the past several years. It has been demonstrated that dogs can use a number of human social cues to successfully accomplish a task, and that they do so better than apes. Many authors agree that these abilities are a result of 10,000 years of domestication by humans. Domestication may have genetically predisposed dogs to accurately recognize human communication signals. However, only a few authors have studied the performance of working dogs, implying recognition of human communication signals. Haverbeke et al. (2008) found that military working dogs do not always perform as they are expected to. To investigate this finding, we studied the performance of obedience and protection work exercises between 2 groups of dog-handler teams: a control group (CG), trained using the current training method used by the Belgian Defense, and an experimental group (EG) that underwent a new human familiarization and training program. During obedience and protection work exercises, EG teams obtained better results than CG teams and EG dogs exhibited a higher body posture than CG dogs. The results suggest that even if dogs are genetically predisposed toward the recognition of human communication signals, this aptitude alone does not explain the dogs' performance and their interactions with humans in this study. Regular training combined with positive dog-handler interaction is also required to increase the dog-handler (DH) team's performances.

When do domestic dogs, Canis familiaris, start to understand human pointing? The role of ontogeny in the development of interspecies communication

A decade of research indicates that domestic dogs are sensitive to a variety of human social cues, including pointing with the hand and arm. Previous studies conducted with puppies as young as 6 weeks old have reported that puppies are able to follow a human pointing gesture, even when they have had little human contact. These results have led some experimenters to conclude that ontogeny does not contribute to dogs' ability to understand human cues. To determine the age at which domestic dogs first show the ability to understand human pointing cues, we tested puppies in their human caregivers' homes when the puppies were 9–24 weeks old. We found little evidence that puppies younger than 21 weeks had the ability to follow human pointing gestures.

Dingoes (Canis dingo) can use human social cues to locate hidden food

There is contention concerning the role that domestication plays in the responsiveness of canids to human social cues, with most studies investigating abilities of recognized domestic dog breeds or wolves. Valuable insight regarding the evolution of social communication with humans might be gained by investigating Australian dingoes, which have an early history of domestication, but have been free-ranging in Australia for approximately 3500-5000 years. Seven 'pure' dingoes were tested outdoors by a familiar experimenter using the object-choice paradigm to determine whether they could follow nine human communicative gestures previously tested with domestic dogs and captive wolves. Dingoes passed all cues significantly above control, including the "benchmark" momentary distal pointing, with the exception of gaze only, gaze and point, and pointing from the incorrect location. Dingo performance appears to lie somewhere between wolves and dogs, which suggests that domestication may have played a role in their ability to comprehend human gestures.

Testing the social dog hypothesis: Are dogs also more skilled than chimpanzees in non-communicative social tasks?

Relative to non-human primates, domestic dogs possess a number of social skills that seem exceptional-particularly in solving problems involving cooperation and communication with humans. However, the degree to which dogs' unusual skills are contextually specialized is still unclear. Here, we presented dogs with a social problem that did not require them to use cooperative-communicative cues and compared their performance to that of chimpanzees to assess the extent of dogs' capabilities relative to those of non-human primates. We tested the abilities of dogs and chimpanzees to inhibit previously learned responses by using a social and a non-social version of a reversal learning task. In contrast to previous findings in cooperative-communicative social tasks, dogs were not more skilled on the social task than the non-social task, while chimpanzees were significantly better in the social paradigm. Chimpanzees were able to inhibit their prior learning better and more quickly in the social paradigm than they were in the non-social paradigm, while dogs took more time to inhibit what they had learned in both versions of the task. These results suggest that the dogs' sophisticated social skills in using human social cues may be relatively specialized as a result of domestication.