Article

Comprehension of human pointing gestures in young human-reared wolves (Canis lupus) and dogs (Canis familiaris)

Authors:
To read the full-text of this research, you can request a copy directly from the authors.

Abstract

Dogs have a remarkable skill to use human-given cues in object-choice tasks, but little is known to what extent their closest wild-living relative, the wolf can achieve this performance. In Study 1, we compared wolf and dog pups hand-reared individually and pet dogs of the same age in their readiness to form eye-contact with a human experimenter in an object-choice task and to follow her pointing gesture. The results showed that dogs already at 4 months of age use momentary distal pointing to find hidden food even without intensive early socialization. Wolf pups, on the contrary, do not attend to this subtle pointing. Accordingly in Studies 2 and 3, these wolves were tested longitudinally with this and four other (easier) human-given cues. This revealed that wolves socialized at a comparable level to dogs are able to use simple human-given cues spontaneously if the human's hand is close to the baited container (e.g. touching, proximal pointing). Study 4 showed that wolves can follow also momentary distal pointing similarly to dogs if they have received extensive formal training. Comparing the wolves to naïve pet dogs of the same age revealed that during several months of formal training wolves can reach the level of dogs in their success of following momentary distal pointing in parallel with improving their readiness to form eye-contact with a human experimenter. We assume that the high variability in the wolves' communicative behaviour might have provided a basis for selection during the course of domestication of the dog.

No full-text available

Request Full-text Paper PDF

To read the full-text of this research,
you can request a copy directly from the authors.

... Such research has focused on domestic dogs, as pet dogs generally perform well on point-following tasks (Lazarowski & Dorman, 2015;Miklósi, Polgárdi, Topál, & Csányi, 1998;Udell, Dorey, & Wynne, 2008). Furthermore, initial studies have suggested that wolves performed poorly at point-following tasks, especially compared with dogs (Hare, Brown, Williamson, & Tomasello, 2002;Virányi et al., 2008). This suggested that perhaps point following was an evolved behavior as a by-product of domestication and cohabitation with humans (Hare et al., 2002;Hare et al., 2010;Hare & Tomasello, 2005;Riedel, Schumann, Kaminski, Call, & Tomasello, 2008;Virányi et al., 2008). ...
... Furthermore, initial studies have suggested that wolves performed poorly at point-following tasks, especially compared with dogs (Hare, Brown, Williamson, & Tomasello, 2002;Virányi et al., 2008). This suggested that perhaps point following was an evolved behavior as a by-product of domestication and cohabitation with humans (Hare et al., 2002;Hare et al., 2010;Hare & Tomasello, 2005;Riedel, Schumann, Kaminski, Call, & Tomasello, 2008;Virányi et al., 2008). This behavior at first seemed to be unique to domestic dogs, as other nonhuman species, even chimpanzees, have been shown to fail to follow human gestures (Kirchhofer, Zimmermann, Kaminski, & Tomasello, 2012). ...
... This behavior at first seemed to be unique to domestic dogs, as other nonhuman species, even chimpanzees, have been shown to fail to follow human gestures (Kirchhofer, Zimmermann, Kaminski, & Tomasello, 2012). However, subsequent studies have found evidence supporting that chimpanzees and wolves are both capable of using human pointing gestures at the same level or better than dogs with intensive socialization or extensive training (Hopkins, Russell, McIntyre, & Leavens, 2013;Udell et al., 2008;Virányi et al., 2008). Virányi et al. (2008) showed that at the age of 4 months, dog pups outperform wolf pups at a pointing task, however adult wolves are able to perform comparably to adult dogs with extensive training and socialization. ...
Article
Full-text available
Pet dogs are known to be responsive to human pointing gestures, but shelter dogs have repeatedly demonstrated poor abilities to follow human pointing, although they can be explicitly trained quickly. This study evaluated the time course in which shelter dogs learn to follow points without explicit training, when given typical interactions with humans. In a longitudinal evaluation, the development of point following was tracked in seven shelter dogs in a training program (enriched human exposure), seven dogs in a traditional shelter (control population), and evaluated once in pet dogs. Twice a week for 6 weeks, shelter dogs’ point-following performance was evaluated in 10 probe trials in which an experimenter pointed to one of two containers equidistant from the dog. To avoid direct training, dogs were given a treat for approaching and touching either container; although correct responses were recorded for touching the pointed-towards container within 30 s. Pet dogs were tested in only one session. All shelter dogs initially showed the expected poor performance. However, enriched shelter dogs receiving enriched human exposure showed significant improvements reaching an identical performance to pet dogs within 7 weeks. In comparison, shelter dogs under standard conditions showed an initial improvement, but performance reached asymptote close to chance levels and lower than that of enriched dogs or pet dogs. Together, these results suggest that enriched experiences with humans, typical of pet dogs, is sufficient for dogs to learn to follow points without explicit training.
... The exact experimental setup and procedure details were also found to affect performance in the pointing task (Pongrácz et al. 2013). Consequently, slight differences in our procedure compared to others' (e.g., lack of pre-training to both sides, as, e.g., in Gácsi et al. 2009bor Virányi et al. 2008 or the setup, such as somewhat bigger distance between the two objects and/or the tip of the pointing finger and the container (as in, e.g., Virányi et al. 2008) could also cause the task to be more difficult for the dogs participating in our study. ...
... The exact experimental setup and procedure details were also found to affect performance in the pointing task (Pongrácz et al. 2013). Consequently, slight differences in our procedure compared to others' (e.g., lack of pre-training to both sides, as, e.g., in Gácsi et al. 2009bor Virányi et al. 2008 or the setup, such as somewhat bigger distance between the two objects and/or the tip of the pointing finger and the container (as in, e.g., Virányi et al. 2008) could also cause the task to be more difficult for the dogs participating in our study. ...
... One particular advantage of this study, in line with some previous ones comparing, e.g., the interspecific social skills of dogs and cats (Miklósi et al. 2005) or wolves (e.g., Virányi et al. 2008) is that we aimed to ensure that subjects are raised in similar environments providing comparable social stimulation by humans. This reduces the chance that any differences that emerged are due to a general determinative difference in the two species' experience with humans. ...
Article
Full-text available
Previous research proves dogs’ outstanding success in socio-communicative interactions with humans; however, little is known about other domestic species’ interspecific skills when kept as companion animals. Our aim was to assess highly socialized young miniature pigs’ spontaneous reactions in interactions with humans in direct comparison with that of young family dogs. All subjects experienced similar amount of socialization in human families. In Study 1, we investigated the appearance of human-oriented behaviours without the presence of food (Control condition) when a previously provided food reward was withheld (Food condition). In Study 2, we measured responsiveness to two types of the distal pointing gesture (dynamic sustained and momentary) in a two-way object choice test. In the Control condition of Study 1, the duration of pigs’ and dogs’ orientation towards and their frequency of touching the human’s body was similar. In the Food condition, these behaviours and orienting to the human’s face were intensified in both species. However, pigs exhibited face-orientation to an overall lesser extent and almost exclusively in the Food condition. In Study 2, only dogs relied spontaneously on the distal dynamic-sustained pointing gesture, while all pigs developed side bias. The results suggest that individual familiarization to a human environment enables the spontaneous appearance of similar socio-communicative behaviours in dogs and pigs, however, species predispositions might cause differences in the display of specific signals as well as in the success of spontaneously responding to certain types of the human pointing gestures.
... We used dynamic and momentary gazing signals, because our second goal was to test whether the nature of the referential signal would affect the cats' success rate. In the case of dynamic signals, the gazing posture is sustained until the subject makes a choice, therefore, based on pointing experiments done with dogs and wolves (Virányi et al., 2008), one could expect that cats would perform with a higher success rate when the gazing is dynamic. However, in the case of momentary gazing, when the signal consists of a brief look at the target, then the experimenter takes back her/his glance to the subject, the movement is more apparent, therefore one could also expect that for a predatory species (such as the dog and the cat), these cues would be more salient (i.e. ...
... Similarly to cats, in companion dogs it was also found that even very young subjects perform with remarkable success in two-way choice experiments based on following human visual cues (Gácsi, McGreevy, Kara, & Miklósi, 2009). In comparative experiments it was also shown that young dogs do not require excessive training (repeated testing) for being successful in point-following, while intensively socialized young wolves reached the success level of dogs only when they were 11 months old (Virányi et al., 2008). It is also worth to mention that adult socialized wolves were shown to be capable of outperforming shelter dogs in following human pointing where the latter were of unknown level of socialization (Udell, Dorey, & Wynne, 2008). ...
... It is also worth to mention that adult socialized wolves were shown to be capable of outperforming shelter dogs in following human pointing where the latter were of unknown level of socialization (Udell, Dorey, & Wynne, 2008). In the case of making eye contact with humans, young dogs develop this skill seemingly spontaneously compared to socialized wolves, which require a lengthy and frequently repeated exposure to communicative tasks with humans to reaching the level of dogs (Gácsi et al., 2005;Miklósi et al., 2003;Virányi et al., 2008). Based on our results showing the high performance of young cats in the gaze following task, we can assume that the development of this skill starts early and may only require a relatively short learning period in cats. ...
Article
Companion cats often occupy the same anthropogenic niche as dogs in human families. Still, cat cognition remains an underrepresented research subject in ethology. Our goal was to examine whether two components that are crucial in dog-human communicative interactions (sensitivity to ostensive signals; gaze following) are also present in cats. In a two-object choice task, we used dynamic and momentary gazing in ostensive and non-ostensive communicative situations. We tested 41 cats at their owner's home. Cats on the group level achieved a 70% overall success rate, showing that they are capable of following human gaze as a referential cue. Cats' success rate was unaffected both by the type of gazing and the presence/absence of ostensive communication, showing that the subjects followed readily even the more difficult momentary cues. We found a trend (p = 0.085), showing that young cats (max. 1 year old) may achieve higher success rate than adult animals. Ostension had a significant effect on the latency of eye contact, which was the shortest when the experimenter called the cat's attention with ostensive signals (p = 0.006). Our results are the first that prove cats' ability to follow human gaze, which is considered to be one of the more difficult visual referential signals given during human-animal interactions. Although ostension did not affect the success rate of cats, we found ostensive human signals to be a more effective attention elicitor compared to non-ostensive vocalizations. Our study therefore provided the first insight to the existence of sensitivity to human ostension in another non-human species besides dogs. These results emphasize the possible relevance of the domestication process and responsiveness to socialization in the development of human-compatible socio-cognitive skills even in such animals as the cat, where the ancestor was not a highly social species.
... Nesses experimentos, os animais são expostos a tarefas em que devem responder a dicas humanas (Hare, Brown, Williamson, & Tomasello, 2002;Miklósi, Kubinyi, Topál, Gácsi, Virányi, & Csányi. 2003;Virányi et al, 2008;Udell, Dorey, & Wynne, 2008). Há variações experimentais que manipulam a história de vida dos animais com os humanos (e.g., uso de lobos que recebem cuidados de humanos e uso de cães de abrigo, que teriam menos contato com humanos) e que manipulam as condições experimentais relativas tanto ao local em que o teste é feito, quanto aos estímulos físicos ou sociais (Hare, Rosati, Kaminski, Braüer, Call, & Tomasello, 2010;Miklósi, Kubinyi, Topál, Gácsi, Virányi, & Csányi, 2003;Udell, Dorey, & Wynne, 2008). ...
... Há variações experimentais que manipulam a história de vida dos animais com os humanos (e.g., uso de lobos que recebem cuidados de humanos e uso de cães de abrigo, que teriam menos contato com humanos) e que manipulam as condições experimentais relativas tanto ao local em que o teste é feito, quanto aos estímulos físicos ou sociais (Hare, Rosati, Kaminski, Braüer, Call, & Tomasello, 2010;Miklósi, Kubinyi, Topál, Gácsi, Virányi, & Csányi, 2003;Udell, Dorey, & Wynne, 2008). A vertente etológica tem defendido que os cães respondem rapidamente ao comando humano e necessitam menos treino para as tarefas em que há dicas humanas do que lobos (Lakatos, 2011;Hare et al, 2002;Virányi et al, 2008). Isso seria atribuído a uma história evolutiva compartilhada: ao longo do processo de domesticação, teriam sido selecionados animais que utilizassem de forma eficiente as dicas dadas pelo comportamento humano. ...
... Altura, formato, orientação e opacidade das barreiras, bem como a iluminação sobre o humano e o que ele está fazendo, são alterados para avaliar se os cães identificam se o humano pode ou não pode ver o que estão fazendo, e se são sensíveis a isso (Kaminski, Bräuer, Call, & Tomasello, 2009;Savalli, Resende, & Ades, 2013;Savalli, Resende, & Gaunet, 2016, ver também Capítulo 2). Pesquisadores discutem se a resposta do cão pode ser atribuída a uma história de aprendizagem (Udell et al, 2011), ou se o cão é capaz de se colocar no lugar do outro (Virányi et al, 2008). ...
... Most notably, dogs are able to follow human communicative cues from an early age, before they have had the opportunity to learn the importance of these cues from experience (Hare et al., 2002;Riedel et al., 2008;Rossano et al., 2014). Crucially, this early ability to follow communicative cues is not shared by dogs' close, nondomesticated relativesgray wolves (Canis lupus; e.g., Gácsi et al., 2009;Hare et al., 2010;Virányi et al., 2008). Even wolf cubs hand-raisedbyhumansdonotfollowhumancommunicative cues as young dogs do (e.g., Gácsi et al., 2009;Virányi et al., 2008). ...
... Crucially, this early ability to follow communicative cues is not shared by dogs' close, nondomesticated relativesgray wolves (Canis lupus; e.g., Gácsi et al., 2009;Hare et al., 2010;Virányi et al., 2008). Even wolf cubs hand-raisedbyhumansdonotfollowhumancommunicative cues as young dogs do (e.g., Gácsi et al., 2009;Virányi et al., 2008). Thus, dogs seem to have developed the ability to follow human communicative cues across domestication in a way that's not shared in non-domesticated canids. ...
Article
Human children and domesticated dogs learn from communicative cues, such as pointing, in highly similar ways. In two experiments, we investigate whether dogs are biased to defer to these cues in the same way as human children. We tested dogs on a cueing task similar to one previously conducted in human children. Dogs received conflicting information about the location of a treat from a Guesser and a Knower, who either used communicative cues (i.e., pointing; Experiments 1 and 2), non-communicative physical cues (i.e., a wooden marker; Experiment 1), or goal-directed actions (i.e., grasping; Experiment 2). Although human children tested previously struggled to override inaccurate information provided by the Guesser when she used communicative cues, in contrast to physical cues or goal-directed actions, dogs were more likely to override the Guesser’s information when she used communicative cues or goal-directed actions than when she used non-communicative physical cues. Given that dogs did not show the same selective bias towards the Guesser’s information in communicative contexts, these findings provide clear evidence that dogs do not demonstrate a human-like bias to defer to communicative cues. Instead, dogs may be more likely to critically evaluate information presented via communicative cues than either physical or non-communicative cues.
... The dog was first introduced to the bowls by the experimenter, which each contained one treat. The experimental set-up was similar to that of Virányi et al. (2008) and Oliva et al. (2015). The two spaniel bowls were placed 1.5 m apart and the experimenter knelt 30 cm behind the mid-point between the bowls. ...
... Alternatively, this could reflect a change in the wiring of these dogs' brains, due to their particular upbringing. Previous studies have identified individual differences in OCT performance (Miklósi et al., 1998;Agnetta et al., 2000;Hare et al., 2002;Udell et al., 2008a,b;Udell et al., 2010;Virányi et al., 2008;Wobber et al., 2009;Oliva et al., 2016b). Oliva et al. (2016b) investigated whether this could have been due to differences in the OT receptor gene but were not able to demonstrate an association. ...
Article
Full-text available
The neuropeptide oxytocin (OT) has been shown to enhance dogs' ability to perform an object choice task (OCT) involving the use of human pointing cues, when delivered intranasally. This study aimed at further investigating whether OT enhances task performance by increasing choices made, or by increasing correctness of choices made, and to compare these treatment effects to dog appeasing pheromone (DAP), known to balance emotional activation in dogs. Hence, we compared OCT performance between three groups of dogs: (i) dogs administered OT and a sham collar, (ii) dogs administered a saline placebo and a DAP collar, and (iii) control dogs administered a saline placebo and a sham collar. All three groups consisted of a combination of male and female pet dogs and assistance-dogs-in-training currently living with a volunteer carer. The study also evaluated the effect of intranasal OT and/or DAP on plasma levels of OT, and prolactin; which has previously been linked with anxiety in dogs. The dogs' emotional state was measured using the Emotional Disorders Evaluation in Dogs (EDED) scale. The owners'/carers' degree of anxious-and avoidant-style attachment to their dogs was accessed using the Pet Attachment Questionnaire (PAQ). Interesting descriptive data appeared for both treatment groups. Particularly, in OT group, we obtained significant results demonstrating that intranasal OT enhances OCT performance in dogs compared to control, by increasing the percentage of correct choices, but not the number of choices, made. Results also support that the mode of action of intranasal OT is via direct access to the brain and not via the blood, since no elevation of plasma OT (or prolactin) levels were observed after intranasal administration in this study. Similarly, DAP application did not significantly alter OT or prolactin peripheral concentrations. Several differences were observed between fostered and pet dogs, namely: fostered dogs demonstrated higher levels of serum prolactin, made more choices on the OCT compared to pet dogs but were not more likely to be correct, and were fostered by carers with higher avoidant attachment scores than pet dog owners. These findings implicate consideration of potential carer and training consequences for assistance dogs.
... It seems likely that response to point and gaze use emerge very early in dog development (Gácsi, Kara, Belényi, Topál & Miklósi, 2009;Riedel, Schumann, Kaminski, Call, & Tomasello, 2008;Zaine, Domeniconi, & Wynne, 2015). The actual utilization of these cues is somewhat different in dogs, or wolves, that have had less interaction with humans (D'Aniello et al., 2017;Udell, Dorey, & Wynne, 2010;Virányi et al., 2008). It also differs between wolves and dogs, but the exact nature of these differences remains controversial Udell, Dorey, & Wynne, 2008); although attention to human points emerges later in hand-reared wolf cubs than in hand-reared puppies, with appropriate training it can reach the same level in both groups (Virányi et al., 2008). ...
... The actual utilization of these cues is somewhat different in dogs, or wolves, that have had less interaction with humans (D'Aniello et al., 2017;Udell, Dorey, & Wynne, 2010;Virányi et al., 2008). It also differs between wolves and dogs, but the exact nature of these differences remains controversial Udell, Dorey, & Wynne, 2008); although attention to human points emerges later in hand-reared wolf cubs than in hand-reared puppies, with appropriate training it can reach the same level in both groups (Virányi et al., 2008). ...
Article
Full-text available
The great increase in the study of dog cognition in the current century has yielded insights into canine cognition in a variety of domains. In this review, we seek to place our enhanced understanding of canine cognition into context. We argue that in order to assess dog cognition, we need to regard dogs from three different perspectives: phylogenetically, as carnivoran and specifically a canid; ecologically, as social, cursorial hunters; and anthropogenically, as a domestic animal. A principled understanding of canine cognition should therefore involve comparing dogs’ cognition with that of other carnivorans, other social hunters, and other domestic animals. This paper contrasts dog cognition with what is known about cognition in species that fit into these three categories, with a particular emphasis on wolves, cats, spotted hyenas, chimpanzees, dolphins, horses, and pigeons. We cover sensory cognition, physical cognition, spatial cognition, social cognition, and self-awareness. Although the comparisons are incomplete, because of the limited range of studies of some of the other relevant species, we conclude that dog cognition is influenced by the membership of all three of these groups, and taking all three groups into account, dog cognition does not look exceptional.
... The high socio-cognitive abilities of domesticated animals, especially dogs, may also be explained by the high level of attention they pay to humans. For example, dogs have evolved eye contact with humans during the process of domestication 25,26 , which might have resulted in sophisticated socio-cognitive abilities during their interactions with humans. In other words, when the performance of an individual or species on a socio-cognitive test is poor, we should consider several possibilities, especially the following: (1) they cannot do it because of their poor cognitive ability or (2) they can do it but do not because of their low motivation levels. ...
... One is that their lifetime interactions with humans have improved their socio-cognitive abilities towards humans during their ontogenies 34,35 . Second, their high socio-cognitive abilities have evolved through the selection of their socio-cognitive abilities during the domestication process 25,36 . Finally, their high socio-cognitive abilities arose as a by-product of the selection for tameness during the domestication process 37 . ...
Article
Full-text available
When interacting with humans, domesticated species may respond to communicative gestures, such as pointing. However, it is currently unknown, except for in dogs, if species comprehend the communicative nature of such cues. Here, we investigated whether horses could follow the pointing of a human informant by evaluating the credibility of the information about the food-hiding place provided by the pointing of two informants. Using an object-choice task, we manipulated the attentional state of the two informants during food-hiding events and differentiated their knowledge about the location of the hidden food. Furthermore, we investigated the horses’ visual attention levels towards human behaviour to evaluate the relationship between their motivation and their performance of the task. The result showed that horses that sustained high attention levels could evaluate the credibility of the information and followed the pointing of an informant who knew where food was hidden (Z = − 2.281, P = 0.002, n = 36). This suggests that horses are highly sensitive to the attentional state and pointing gestures of humans, and that they perceive pointing as a communicative cue. This study also indicates that the motivation for the task should be investigated to determine the socio-cognitive abilities of animals.
... The so-called 'looking back behaviour' is a singular behaviour observed in both dogs and wolves and it has been widely discussed. The expression of this behavior in dogs seems to be related to several problem-solving tasks, such as: the detour task , object-choice paradigm (Viranyi et al. 2008), in situations where dogs witness an object of desire being hidden (Gaunet and Deputte 2011;Polgárdi et al. 2000) or placed out of reach (Barrera et al. 2011;Jakovcevic et al. 2012), or when they are confronted with an unknown and potentially scary object (Merola et al. 2012). Indeed, wolves were found capable of following both human and conspecific gaze from behind a barrier, as well as human gazing into distant space . ...
... Generally, wolves are more focused on the problem, more persistent, they are faster and more successful at obtaining food from puzzle boxes (Udell 2015;Rao et al. 2018;Frank and Frank 1982). These differences have partly been attributed to the different ecological niches they live in (Viranyi et al. 2008;Marshall-Pescini et al. 2015Range and Viranyi 2013;Werhahn et al. 2016). In a recent study, Marshall-Pescini et al. (2017) tested similarly raised adult wolves and mixed-breed dogs, pet dogs and freeranging dogs. ...
Article
Full-text available
To elucidate the role of domestication, we used the impossible task paradigm to test Czechoslovakian Wolfdogs with a known proportion of ‘wolfblood’ in their DNA and, as a control group for our subjects, we used German shepherd dogs. We hypothesized that the difference between wolves and domestic dogs is based on genetics and modified by obedience; if so, the looking back performance of the subject should be linked to its proportion of wolf-genes. To prove that, we observed 73 Czechoslovakian Wolfdogs, and 27 German shepherd dogs, and analysed their human-directed gazing behaviour during our test. Our apparatus consisted of a glass container placed upside down over a small amount of food. The test proceeded with three solvable trials, in which the subject could obtain the food by manipulating the container, followed by an unsolvable one in which the container was fixed onto the board. Our results suggest that there is no significant correlation between the probability of looking back in Czechoslovakian Wolfdogs and their proportion of ‘wolf blood’. However, the probability of looking back was higher in German Shepherd dogs than in Czechoslovakian Wolfdogs (odds ratio = 9.1). German Shepherd dogs showed not only a higher frequency of looking back, but also the duration of their looks was longer.
... The ability to read human cues has been found in many other species such as goats , wolves , foxes , different species of primate (Anderson et al. 1995, Itakura and Tanaka 1998, Vick and Anderson 2003, ravens (Bugnyar et al. 2004), dolphins (Pack andHerman 2004), and horses (McKinley andSambrook 2000, Proops et al. 2010). It was probably the domestication process that led to select this characteristic in dogs, so they are now naturally equipped to understand human communicative gestures (Call and Tomasello 1994, Herman et al. 1999, Hare et al. 2002, Virányi et al. 2008, Pika and Bugnyar 2011. Supporting this theory, Hare and colleagues found that captive foxes selected for their tameness for generations could correctly interpret human referential gestures compared to non-selected foxes; on the other hand, young wolves raised by hand cannot interpret human referential gestures as well as dogs (Virányi et al. 2008). ...
... It was probably the domestication process that led to select this characteristic in dogs, so they are now naturally equipped to understand human communicative gestures (Call and Tomasello 1994, Herman et al. 1999, Hare et al. 2002, Virányi et al. 2008, Pika and Bugnyar 2011. Supporting this theory, Hare and colleagues found that captive foxes selected for their tameness for generations could correctly interpret human referential gestures compared to non-selected foxes; on the other hand, young wolves raised by hand cannot interpret human referential gestures as well as dogs (Virányi et al. 2008). Against the theory claiming a natural predisposition of dogs in understanding human non-verbal communication, there are other studies that have compared the same skills in wolves socialized with humans, owned dogs and rescued dogs hosted in shelters (Udell et al. , 2010. ...
... Many dog researchers are interested in understanding dog behavior in the context of the species' shared environment with humans, both in the present-day and during the domestication process. Many contentions in the literature have arisen from different views regarding how genetics and ontogeny determine cognitive abilities of dogs (Dorey et al. 2009(Dorey et al. , 2010Hare et al. 2002Hare et al. , 2009Hare and Tomasello 2005;Merritt 2015;Virányi et al. 2008), and both of these factors likely influence EF in important ways. ...
... To better understand how domestication might have affected EF, Marshall-Pescini et al. (2015) compared the performance of human-reared wolves on the cylinder task with that of trained and untrained pet dogs and human-reared "free-ranging" dogs. They found that dogs, regardless of training or housing situation, outperformed wolves and suggested that dogs might have used inadvertent human cues that led to their successful performance; however, there is conflicting evidence as to whether there exists a difference in the ability to follow human social cues between wolves and dogs (Hare and Tomasello 2005;Udell et al. 2008;Virányi et al. 2008). Further, researchers should use caution when comparing the performance of dogs to that of modern-day wolves when trying to understand the effects of domestication (see Kruska 1988). ...
... One explanation for the impressive skills of dogs in the object-choice task is that human domestication of the dog has yielded genetic changes that give dogs the ability to understand the gestures of their human owners [1,3]. Evidence given in favour of this is that dogs' progenitors, the wolf (Canis lupus), often perform poorly in object choice tasks [1,4] and domesticated silver fox puppies (Vulpes vulpes) that were experimentally domesticated over several generations are as skilful as dog puppies in the task and perform better than their undomesticated conspecifics [5]. An alternative theory to the domestication hypothesis is that the ability to follow human communicative gestures develops when dogs become human companions and then, over time, they learn how to correctly respond to such gestures during their extensive exposure to them. ...
... In the 22 objectchoice task dog studies reviewed by Mulcahy & Hedge [2] only four studies explicitly reported the exact method. In three studies the handler held the subject by the collar and then released the subject [14][15][16] and in one study the handler restrained the subjects by the leash and released them by letting go of the leash [4]. ...
Article
Full-text available
Unlike other animal species, domesticated pet dogs reliably use a range of human communicative cues to find a hidden reward in the object-choice task. One explanation for this finding is that dogs evolved skills for understanding human communicative behaviour during and as a result of human domestication. However, contrary to this domestication hypothesis, Udell et al. found domesticated shelter dogs failed to locate a hidden reward using a human’s distal point cue, a cue pet dogs easily use. Hare et al., however, suggested the unorthodox methods used in Udell et al.’s object-choice task resulted in the shelter dogs failing to use human cues. In support of this, Hare et al. found that shelter dogs could use a human communicative pointing cue when tested with a standard object-choice task method. Yet in contrast to Udell et al., Hare at al. used a much simpler proximal cue that cannot exclude success based on stimulus enhancement rather than an understanding of the cue’s communicative nature. We therefore addressed this issue by testing shelter dogs’ abilities to use a range of proximal and distal human communicative cues in a standard object-choice task. We found shelter dogs could use proximal cues that may involve stimulus enhancement, but they continuously failed to use distal cues that excluded this possibility. Object-choice tasks with dogs typically involve non-vocalised human cues. We tested if vocalising would help shelter dogs to use distal cues. We found shelter dogs could use a vocalised distal continuous cue when the subject’s name was called during cue presentation. It is therefore possible that vocalised cues help domesticated dogs learn about non-vocalised human communicative cues. Overall our results do not support that domesticated dogs’ understanding of human communicative cues is a direct result of the domestication process.
... The differential performances of domestic dogs and nonhuman primates on the Object-Choice Task (OCT), which measures an individual's ability to follow human gestural cues, have led to phylogenetic theories regarding their respective socio-cognitive abilities. Numerous studies (e.g., Riedel et al. 2008;Virányi et al. 2008) report that domestic dogs possess specialised skills in comprehending human communicative cues, evidenced by their high levels of performance on the Object-Choice Task (OCT). Whether emerging as a by-product of domestication (Hare and Tomasello 2005) or as a result of humans' active selection for dogs with specific traits (Miklósi et al. 2003), there is a consensus among some researchers that dogs have an evolved ability to follow human gestural cues. ...
... This is further highlighted by the dogs' chance-level performance in the barrier condition in Study 2. That behavioural differences were found as a function of the presence of a barrier has important implications for claims of evolved specialised socio-cognitive skills in dogs (e.g., Hare and Tomasello 2005). Such claims are made with reference to an evidence base of OCT studies in which dogs show apparent consistently high levels of performance (e.g., Riedel et al. 2008;Virányi et al. 2008); however, the current studies add to a growing body of research that demonstrates the effects of environmental influences on dogs' performance (e.g., D'Aniello et al. 2017;Lazarowski and Dorman 2015;Udell et al. 2010a) thus supporting claims for a greater role of ontogeny than is accounted for in domestication theories. ...
Article
Full-text available
Recent reviews have found marked procedural and methodological differences in the testing of different taxonomic groups on the object-choice task. One such difference is the imposition of a barrier in the testing environment of nonhuman primates in the form of a cage, necessitated to ensure the experimenter’s safety. Here, we conducted two studies with domestic dogs (Canis lupus familiaris) in which we compared the performance of dogs tested from within a child’s playpen and dogs tested without this barrier present. In Study 1, in a within-subjects design, we found no effect of the barrier on dogs’ ability to use a pointing cue, but there was an increase in instances in which dogs failed to choose a cup. In Study 2, in a between-subjects design, dogs tested with a barrier failed to perform above chance, and were also more likely to fail to make a choice. When dogs tested without a barrier made an incorrect response, these were more likely to be incorrect choices than no choice errors. We discuss the implications of these differences in behavioural responses in function of the presence of a barrier and the necessity of ensuring matched conditions when comparing across species.
... Young dogs follow human pointing better and look at humans more readily than human-raised wolves Gácsi et al., 2009). This led researchers to propose that dogs have developed increased social attentiveness compared to wolves and, thus, can achieve more complex forms of dog-human communication and cooperation than wolves Virányi et al., 2008). ...
... However, as most of the studies compared the animals' interactions only with humans (Hare et al., 2002;Miklósi et al., 2003;Topál et al., 2005;Virányi et al., 2008;Gácsi et al., 2009;Udell et al., 2011), it remained unclear whether the differences between dogs and wolves reflect mere differences in the readiness of dogs and wolves to interact with humans or more fundamental differences regarding intraspecific cooperation. Indeed, experiments at the Wolf Science Center in Austria have shown that (hand-raised) wolves pay as much attention to human partners as dogs do and that these wolves can even outperform dogs in learning from observation of a conspecific, indicating the high social attentiveness of the species Virányi, 2013, 2014). ...
Article
Full-text available
Humans interact with animals in numerous ways and on numerous levels. We are indeed living in an "animal"s world,' in the sense that our lives are very much intertwined with the lives of animals. This also means that animals, like those dogs we commonly refer to as our pets, are living in a "human's world" in the sense that it is us, not them, who, to a large degree, define and manage the interactions we have with them. In this sense, the human-animal relationship is nothing we should romanticize: it comes with clear power relations and thus with a set of responsibilities on the side of those who exercise this power. This holds, despite the fact that we like to think about our dogs as human's best friend. Dogs have been part of human societies for longer than any other domestic species. Like no other species they exemplify the role of companion animals. Relationships with pet dogs are both very widespread and very intense, often leading to strong attachments between owners or caregivers and animals and to a treatment of these dogs as family members or even children. But how does this relationship look from the dogs' perspective? How do they perceive the humans they engage with? What responsibilities and duties arise from the kind of mutual understanding, attachment, and the supposedly "special" bonds we form with them? Are there ethical implications, maybe even ethical implications beyond animal welfare? The past decades have seen an upsurge of research from comparative cognition on pet dogs' cognitive and social skills, especially in comparison with and reference to humans. We will therefore set our discussion about the nature and ethical dimensions of the human-dog relationship against the background of the current empirical knowledge on dog (social) cognition. This allows us to analyze the human-dog relationship by applying an interdisciplinary approach that starts from the perspective of the dog to ultimately inform the perspective of humans. It is our aim to thereby identify ethical dimensions of the human-dog relationship that have been overlooked so far.
... Interspecific communication (human-non-human animals), employing directional or referential gestures, has widely been studied in the last two decades. Several non-human animals like chimpanzees and bonobos (Tomasello and Camaioni, 1997;Mulcahy and Call, 2009), orangutans (Zimmermann et al., 2009), horses (Maros et al., 2008;Malavasi and Huber, 2016), seals (Shapiro et al., 2003), elephants (Smet and Byrne, 2013), cats , goats (Kaminski et al., 2005), dogs (Soproni et al., 2001(Soproni et al., , 2002Miklósi and Soproni, 2006), and wolves Virányi et al., 2008) have been shown to respond to such gestures from humans. Although an initial surge was observed in the investigation of interspecific communication using non-human primates, scientists gradually shifted to testing canids which, in turn, facilitated the development and advancement of comparative research methods. ...
Article
Full-text available
Dogs are one of the most common species to be found as pets and have been subjects of human curiosity, leading to extensive research on their socialization with humans. One of the dominant themes in dog cognition pertains to their capacity of understanding and responding to human referential gestures. The remarkable socio-cognitive skills of pet dogs, while interacting with humans, is quite well established. However, studies regarding the free-ranging subpopulations are greatly lacking. The interactions of these dogs with humans are quite complex and multidimensional. For the first time, we tested 160 adult free-ranging dogs to understand their ability to follow relatively complex human referential gestures using dynamic and momentary distal pointing cues. We found that these dogs are capable of following distal pointing cues from humans to locate hidden food rewards. However, approximately half of the population tested showed a lack of tendency to participate even after successful familiarization with the experimental set-up. A closer inspection revealed anxious behavioural states of the individuals were responsible for such an outcome. Finally, we compared the results using data from an earlier study with dynamic proximal cues. We found that free-ranging dogs follow distal cues more accurately compared to proximal cue. We assume that life experiences with humans probably shape personalities of free-ranging dogs, which in turn influence their responsiveness to human communicative gestures.
... Research has suggested that domestic animals have human-directed social skills that are not found in their wild ancestors. This has been particularly investigated in comparative studies between dogs and wolves (Gácsi et al. 2009;Miklósi et al. 2003;Virányi et al. 2008). For example, dogs have been shown to be sensitive to both the attention and emotions revealed by humans Müller et al. 2015;Virányi et al. 2004), to understand various referential gestures (Kaminski and Nitzschner 2013), and to learn from both conspecific and human demonstrators in social-learning tasks (Pongrácz et al. 2005;Scandurra et al. 2015). ...
Article
Full-text available
Due to our long history of living in close association with horses, these animals are suggested to have enhanced skills in understanding and communicating with humans. Today, horses have become important to humans for sport and leisure and their understanding of human behaviour and their human-directed behaviour are therefore of great importance. In this study, we investigated 22 horses in a human contact-seeking experiment where they were presented with an unsolvable problem and a detour experiment with a human demonstrator. The unsolvable problem consisted of pieces of carrot in a closed bucket and the detour resembled the shape of V. Additionally, personality traits of the participating horses were assessed. Interestingly, the full-sized horses (N = 11) showed more human-related behaviours when presented with an unsolvable problem compared to before the carrots were made unreachable (p = 0.033), while the ponies (N = 11) did not. However, neither the full-sized horses nor the ponies were significantly more successful in the detour after human demonstrations than in control trials. When comparing the two experiments, we found the task-oriented behaviour in the detour test to positively correlate with human proximity and eye contact-seeking behaviour towards humans during the unsolvable problem in the contact-seeking test. Interestingly, again this was only true for the full-sized horses (p < 0.05) and not for the ponies. From the horse personality questionnaire results, the traits excitability and anxiousness revealed strong negative correlations with human-directed behaviour in the contact-seeking experiment (p < 0.05). Hence, size (full-sized horse/pony) and personality influenced the human-related behaviours of the horses and we suggest a future focus on these aspects to deepen our understanding of human–horse communication.
... A number of studies also demonstrate the ability of many captive or wild-caught species with considerable human exposure to use humangiven cues to locate food (e.g. Clark's nutcrackers: Tornick et al., 2010; cotton-top tamarins, Saguinus oedipus, rhesus monkeys, Macaca mulatta, and chimpanzees: Wood et al., 2007; dogs and some wolves: Hare and Tomasello, 1999;Virányi et al., 2008;goats: Kaminski et al., 2005; gorillas, Gorilla gorilla: Peignot and Anderson, 1999). Extensive history of explicit training has been assumed to influence the subjects' ability to apprehend and comprehend certain human gestures (Tschudin et al., 2001;Scheumann and Call, 2004). ...
Article
A wide range of species relies on heterospecific visual cues to detect the location of resources like food. Although different hypotheses have been suggested to explain the emergence of this capacity in animals, results are often difficult to interpret due to the influence of other factors, such as close contact with humans. In this study, we presented eight Southern ground-hornbills (Bucorvus leadbeateri) with a two-way object-choice paradigm. The human experimenter provided a static and salient cue indicating which of the two containers was baited in four experimental conditions: (a) Touch, (b) Head, (c) Point + Head, and (d) Point. In an additional control condition (no cues given), we assessed whether subjects relied on olfactory cues to solve the task. Overall, our subjects did not spontaneously use human-given cues and their performance fluctuated near chance during the control condition. Noteworthy, most birds exhibited a side bias towards one container. We do not exclude the possibility that this species may be capable of using other cue types, or learning to use cues, after long interaction with humans is provided.
... Interestingly, many domesticated animals have performed relatively well on similar object-choice tasks (e.g., dogs (Canis familiaris)- Hare et al. 2002, Virányi et al. 2008; goats (Capra hircus)- Kaminski et al. 2005; pigs (Sus scrofa domestica) -Nawroth et al. 2014; and horses (Equus caballus)- Maros et al. 2008, Proops et al. 2010. One explanation for the success of these latter species is the so-called domestication hypothesis (Hare et al. 2002), which argues that domesticated animals, through artificial selection for physical or behavioral traits preferred by humans, have gained (either directly or as an evolutionary byproduct) the social capacity for following human-provided cues (but see, for example, Hare et al. 2010;Udell et al. 2008;Range andVirányi 2015, for discussions about this hypothesis). ...
Article
Full-text available
Asian elephants have previously demonstrated an ability to follow olfactory cues, but not human-provided social cues like pointing and gazing or orienting to find hidden food (Plotnik et al. in PLoS One 8:e61174, 2013; Anim Behav 88:91–98, 2014). In a study conducted with African elephants, however, elephants were able to follow a combination of these social cues to find food, even when the experimenter’s position was counter to the location of the food. The authors of the latter study argued that the differences in the two species’ performances might have been due to methodological differences in the study designs (Smet and Byrne in Curr Biol 23(20):2033–2037, 2013). To further investigate the reasons for these potential differences, we partially adapted Smet and Byrne (2013)’s design for a group of Asian elephants in Thailand. In a two-object-choice task in which only one of two buckets was baited with food, we found that, as a group, the elephants did not follow cues provided by an experimenter when she was positioned either equidistant between the buckets or closer to the incorrect bucket when providing the cues. The elephants did, however, follow cues when the experimenter was closer to the correct bucket. In addition, there was individual variability in the elephants’ performance within and across experimental conditions. This indicates that in general, for Asian elephants, the pointing and/or gazing cues alone may not be salient enough; local enhancement in the form of the experimenter’s position in relation to the food reward may represent a crucial, complementary cue. These results suggest that the variability within and between the species in their performance on these tasks could be due to a number of factors, including methodology, the elephants’ experiences with their handlers, ecological differences in how Asian and African elephants use non-visual sensory information to find food in the wild, or some combination of the three.
... Eye contact also helps dogs to know when communication is relevant and directed at them, as dogs tend to ignore human pointing gestures when the human's eyes are not visible (8,9). Dogs, but not wolves, seem to be motivated to establish eye contact with humans from an early age (10,11), and dogs' motivation to establish eye contact with humans seems to be an indicator of the level of attachment between humans and dogs (12). Thus, mutual gaze between dogs and humans seems to be a hallmark of the unique relationship between both species during human cultural evolution. ...
Article
Full-text available
Domestication shaped wolves into dogs and transformed both their behavior and their anatomy. Here we show that, in only 33,000 y, domestication transformed the facial muscle anatomy of dogs specifically for facial communication with humans. Based on dissections of dog and wolf heads, we show that the levator anguli oculi medialis, a muscle responsible for raising the inner eyebrow intensely, is uniformly present in dogs but not in wolves. Behavioral data, collected from dogs and wolves, show that dogs produce the eyebrow movement significantly more often and with higher intensity than wolves do, with highest-intensity movements produced exclusively by dogs. Interestingly, this movement increases paedomorphism and resembles an expression that humans produce when sad, so its production in dogs may trigger a nurturing response in humans. We hypothesize that dogs with expressive eyebrows had a selection advantage and that “puppy dog eyes” are the result of selection based on humans’ preferences.
... During the process of domestication, dogs have also been "worked" under various situation (for a review see [3]), so that they acquired the ability to discern social information from human body signals. Dogs successfully follow human pointing gestures at a much younger age than their closest wild-living relative (i.e., wolf, Canis lupus), even when hand-reared [4]. Furthermore, dog-owners use a variety of hand signs as non-verbal signals toward their dogs, which provide cues for following human intentions; however, little is known as to dogs' attentional patterns to these hand signs. ...
Article
Full-text available
Dogs have developed a social competence tuned to communicate with human and acquire social information from body signals as well as facial expressions. However, less is known regarding how dogs shift attention toward human body signals, specifically hand signs. Comparison among visual attentional patterns of dogs toward whole body of human being, conspecifics, and other species will reveal dogs’ basic social competences and those specialized to inter-species communication with humans. The present study investigated dogs’ gazing behaviors in three conditions: viewing humans with or without hand signs, viewing conspecifics, and viewing cats. Digital color photographs were presented on a liquid crystal display monitor, and subject dogs viewed the images while their eyes were tracked. Results revealed that subjects gazed at human limbs more than limbs within conspecific and cat images, where attention was predominately focused on the head and body. Furthermore, gaze toward hands was greater in the human hand sign photos relative to photos where human hand signs were not present. These results indicate that dogs have an attentional style specialized for human non-verbal communication, with an emphasis placed on human hand gestures.
... The use of referential signalling has been studied in some bird species (ravens, Pika & Bugnyar, 2011, Australian magpies; Kaplan 2011), coral reef fish (Vail et al. 2013), and a variety of non-primate mammal species (dogs, Canis lupus familiaris, Gaunet & Deputte 2011;dolphins;Xitco et al. 2004; horses, Malavasi & Huber 2016; wolves, Canis lupus, Virányi et al. 2008; seals, Halichoerus grypus, Shapiro et al. 2003). Systematic comparisons of referential skills are however severely hampered by differences in methodology such as for instance intra-versus interspecies interactions. ...
... They were faster and more successful at obtaining food from puzzle boxes (Frank & Frank, 1982;Udell, 2015;Rao et al., 2017;Brubaker et al., 2017) and performed better at a visual discrimination task than dogs (Frank et al., 1989). These differences have partly been attributed to the different ecological niches they live in (Virányi et al., 2008;Range & Virányi, 2013Marshall-Pescini, Virányi & Range, 2015;Werhahn et al., 2016;Marshall-Pescini et al., 2017a, 2017cBrubaker et al., 2017). Unlike wolves, dogs live in a human dominated niche (Marshall-Pescini et al., 2017a). ...
Article
Full-text available
Despite being closely related, dogs perform worse than wolves in independent problem-solving tasks. These differences in problem-solving performance have been attributed to dogs’ greater reliance on humans, who are usually present when problem-solving tasks are presented. However, more fundamental motivational factors or behavioural traits such as persistence, motor diversity and neophobia may also be responsible for differences in task performance. Hence, to better understand what drives the differences between dogs’ and wolves’ problem-solving performance, it is essential to test them in the absence of humans. Here, we tested equally raised and kept dogs and wolves with two unsolvable tasks, a commonly used paradigm to study problem-solving behaviour in these species. Differently from previous studies, we ensured no humans were present in the testing situation. We also ensured that the task was unsolvable from the start, which eliminated the possibility that specific manipulative behaviours were reinforced. This allowed us to measure both persistence and motor diversity more accurately. In line with previous studies, we found wolves to be more persistent than dogs. We also found motor diversity to be linked to persistence and persistence to be linked to contact latency. Finally, subjects were consistent in their performance between the two tasks. These results suggest that fundamental differences in motivation to interact with objects drive the differences in the performance of dogs and wolves in problem-solving tasks. Since correlates of problem-solving success, that is persistence, neophobia, and motor diversity are influenced by a species’ ecology, our results support the socioecological hypothesis, which postulates that the different ecological niches of the two species (dogs have evolved to primarily be scavengers and thrive on and around human refuse, while wolves have evolved to primarily be group hunters and have a low hunting success rate) have, at least partly, shaped their behaviours.
... They were faster and more successful at obtaining food from puzzle boxes (Frank & Frank, 59 1982;Udell, 2015;Rao et al., 2017;Brubaker et al., 2017) and performed better at a visual 60 discrimination task than dogs (Frank et al., 1989). These differences have partly been attributed to the 61 different ecological niches they live in ( Virányi et al., 2008;Range & Virányi, 2013Marshall62 Pescini, Virányi & Range, 2015;Werhahn et al., 2016;Marshall-Pescini et al., 2017c,a;Brubaker et 63 al., 2017). Unlike wolves, dogs live in a human dominated niche (Marshall-Pescini et al., 2017a). ...
Preprint
Full-text available
Despite being closely related, dogs consistently perform worse than wolves in independent problem-solving tasks. These differences in problem-solving performance have been attributed to dogs’ greater reliance on humans, who are usually present when problem-solving tasks are presented. However, more fundamental motivational factors or behavioural traits such as persistence, behavioural variety and neophobia may also be responsible for differences in task performance. Hence, to better understand what drives dogs’ and wolves’ different problem-solving performance, it is essential to test them in the absence of humans. Here, we tested equally raised and kept dogs and wolves with two unsolvable tasks, a commonly used paradigm to study problem-solving behaviour in these species. Differently from previous studies, we ensured no humans were present in the testing situation. We also ensured that the task was unsolvable from the start which eliminated the possibility that specific manipulative behaviours was reinforced. This allowed us to measure both persistence and behavioural flexibility more accurately. In line with previous studies, we found wolves to be more persistent than dogs. We also found behavioural variety to be linked to persistence and persistence to be linked to contact latency. Finally, subjects were consistent in their performance between the two tasks. These results suggest that fundamental differences in motivation to interact with objects drive the performance of wolves and dogs in problem solving tasks. Since correlates of problem-solving success i.e. persistence, neophobia, and behavioural variety are influenced by species’ ecology, our results support the social ecology hypothesis which postulates that the different ecological niches of the two subspecies (dogs have evolved to primarily be scavengers and thrive on and around human refuse, while wolves have evolved to primarily be group hunters and have a low hunting success rate) at least partly shaped their behaviours.
... Among human ostensive signals, eye contact represents the most important and efficient one [7,29]. From an early age, dogs show a spontaneous tendency to gaze at human faces and to make eye contact [32] in a wide range of contexts, for example, in unsolvable tasks or to beg for food from humans [33,34]. Given the specific nature of the contexts in which it is displayed, the human-directed gaze has been interpreted as a "request of help" [7,33]. ...
Article
Full-text available
Simple Summary Communication takes place between members of the same species, as well as between heterospecific individuals, such as the long co-habitation process and inter-dependent relationship present in domestic dogs and humans. Dogs engage in visual communication by modifying different parts of their body; in tactile communication; and also in auditory and olfactory communication, with vocalizations and body odours, respectively. The aim of this review is to provide an overview of the recent literature about dog communication, describing the different nature of the signals used in conspecific and heterospecific interactions and their communicative meaning. Lateralized dog brain patterns underlying basic neural mechanisms are also discussed, for both conspecific and heterospecific social communication. Abstract Dogs have a vast and flexible repertoire of visual, acoustic, and olfactory signals that allow an expressive and fine tuned conspecific and dog–human communication. Dogs use this behavioural repertoire when communicating with humans, employing the same signals used during conspecific interactions, some of which can acquire and carry a different meaning when directed toward humans. The aim of this review is to provide an overview of the latest progress made in the study of dog communication, describing the different nature of the signals used in conspecific (dog–dog) and heterospecific (dog–human) interactions and their communicative meaning. Finally, behavioural asymmetries that reflect lateralized neural patterns involved in both dog–dog and dog–human social communication are discussed.
... In fact, dogs are well able to follow ostensive referential communicative cues (Reid, 2009;Topál et al., 2014), e.g. gazing or pointing (Gácsi et al., 2009;Soproni et al., 2002;Virányi et al., 2008), are sensitive to the attentional states of humans (Call et al., 2003;Schwab and Huber, 2006), and seem to be able to discriminate between basic human emotions (Buttelmann and Tomasello, 2013;Müller et al., 2015). Hence, dogs may have experienced a selective pressure towards keeping high levels of alertness, i.e. to be ready for action when needed, even when resting. ...
Article
Full-text available
Variation in resting behaviour across animals may be driven by adaptations towards their environment. Wolves and dogs seem promising models to examine this idea as they share a common ancestor, but occupy different socio-ecological niches. While wolves generally avoid humans, hunt, defend their territory, and raise offspring cooperatively, most dogs live in human-shaped environments. Hence, we hypothesized wolves to be more alert towards their environment than dogs, i.e. the degree of activation along the sleep-wake continuum (alertness) should be greater in wolves than in dogs. We estimated alertness via cardiac output. We tested similarly raised and kept pack-living wolves and dogs in two different behavioural conditions: (1) inactive wakefulness: animal is lying, head in an upward position with eyes opened, (2) resting: animal is lying, head in downward position with eyes mainly closed. In contrast to our expectations, we found that in both conditions wolves had a lower heart rate and higher heart rate variability than dogs, i.e. wolves might be less alert/more relaxed than dogs. Although our results are preliminary, we suggest that the higher alertness of dogs compared to wolves is potentially driven by differences in their socio-ecology (i.e. domestication) causing greater attention of dogs to human behaviour.
... Existen cinco métodos de abordaje para evaluar el rol del aprendizaje y la ontogenia en una determinada habilidad de los perros: 1) la evaluación de los efectos de la socialización temprana e intensiva, así como del aprendizaje asociativo, en el desarrollo de comportamientos hacia las personas en otros cánidos no domesticados como los lobos y zorros (e.g., Barrera et al., 2012;Virányi et al., 2008); 2) la comparación del desempeño de perros que han tenido diversos programas de adiestramiento con la respuesta de perros sin entrenamiento, así como los efectos de la participación en actividades de adiestramiento (e.g., Marshall-Pescini et al., 2008); 3) la evaluación del efecto de la exposición a diversos procedimientos de aprendizaje, como por ejemplo el reforzamiento, la competencia de claves y la familiaridad (e.g., Bentosela, Barrera, Jakovcevic, Elgier & Mustaca, 2008;; 4) el estudio del desarrollo ontogenético de una determinada habilidad (e.g., Agnetta, Hare & Tomasello, 2000;Kaminski, Schulz & Tomasello, 2012); y 5) la comparación entre perros con diferentes niveles de interacción social con las personas y, por lo tanto, con distintas oportunidades para aprender a partir del contacto con la gente, como por ejemplo los perros de refugio y de familia (e.g., Barrera et al., 2012;Udell et al., 2008). ...
Thesis
El control inhibitorio es una habilidad que permite a los individuos bloquear una respuesta impulsiva y tomar decisiones sobre recompensas a largo plazo. Desde la Psicología Comparada se exponen numerosas razones que justifican al perro como un excelente modelo para estudiar esta capacidad. Sin embargo, este no ha sido ampliamente abordado y los protocolos para evaluarlo en su entorno natural, es decir el compartido con las personas, son escasos. Existe una discusión acerca de las posibles variables que podrían afectar facilitando u obstaculizando el desempeño. Se ha propuesto que un aspecto potencialmente influyente en especies sociales es la naturaleza social o no social del contexto. Asimismo, varias evidencias en humanos demuestran que uno de los factores moduladores de mayor impacto son los aprendizajes y experiencias previas de los sujetos (ontogenia). Por otra parte, se han diseñado diversos paradigmas de evaluación del control de impulsos pero sólo un número limitado de estudios analizaron la convergencia entre los mismos, arrojando resultados contradictorios. En esta Tesis se llevaron a cabo varios experimentos a fin de atender a los problemas presentados. En primer lugar, se diseñaron diferentes protocolos para poder explorar diversos aspectos del control inhibitorio de los perros en situaciones de interacción con los humanos. Los resultados demostraron que estos animales pueden discriminar y seguir claves humanas asociadas a reforzadores con distintas demoras en la entrega, muestran interés por las recompensas a largo plazo y son capaces de inhibir respuestas prepotentes. También se observó una considerable variabilidad entre individuos, lo cual indicaría un impacto notable de las diferencias individuales en el comportamiento. En segundo lugar, se comparó el desempeño en entornos sociales con el rendimiento en ambientes no sociales, a fin de evaluar la influencia del contexto social sobre el control inhibitorio. Se encontró que los perros cometieron significativamente más errores y extinciones de repuesta y menos respuestas correctas en las pruebas no sociales. No obstante, no hubo diferencias significativas entre las condiciones sociales y no sociales considerando los indicadores más relevantes de impulsividad. Estos datos sugieren que, al menos en estos protocolos, el contexto social no tendría un impacto sustancial o no facilitaría el desempeño de los perros. En tercer lugar, se comparó la ejecución de perros de refugio y de familia con el propósito de observar si diferentes niveles de interacción con los humanos durante la ontogenia influyen en esta capacidad. Los perros de refugio mostraron comportamientos significativamente más impulsivos que los de familia en uno de los protocolos sociales. Esto sugiere que la ontogenia afectaría las habilidades inhibitorias. El contacto social restringido de los perros de refugio con las personas limitaría las posibilidades de aprender a controlar impulsos a partir de la interacción con las mismas. Por último, se analizaron las correlaciones entre diversas pruebas con el objetivo de evaluar la convergencia entre diferentes medidas de control inhibitorio. Los resultados no arrojaron asociaciones significativas entre las mismas, lo cual podría indicar que las metodologías no miden el mismo mecanismo subyacente. Esto es compatible con los supuestos de que la impulsividad es multidimensional y el desempeño inhibitorio es dependiente del contexto metodológico específico en el que un sujeto es evaluado. En conjunto, los hallazgos de la Tesis sugieren que los perros son capaces de controlar sus impulsos en situaciones de interacción con las personas. Asimismo, indican que la habilidad podría ser estable a través de los contextos sociales y no sociales. Además, demuestran que la ontogenia desempeña un rol importante en la inhibición comportamental y que las respuestas están afectadas por los distintos métodos de evaluación. Finalmente, los datos en estos animales presentan algunos paralelismos con las evidencias halladas en humanos, aunque los mecanismos podrían diferir entre las especies.
... Domestic dogs, even from a few weeks old, outperform chimpanzees and wolves at a number of tasks in which they must read human communicative signals such as gazing and pointing to locate hidden food (Hare et al. 2002;Riedel et al. 2008;Topál et al. 2014). Virányi et al. (2008) compared handraised 4-month-old wolf and dog puppies, finding that the dogs were both more willing to maintain eye-contact with experimenters, and better able to use the experimenters' points to find hidden food. While wolves were able to learn to respond to ostensive signals after training, the results suggest that dogs possess an early-developing responsiveness to human communication that wolves do not. ...
Article
Full-text available
The previous studies have shown that human infants and domestic dogs follow the gaze of a human agent only when the agent has addressed them ostensively-e.g., by making eye contact, or calling their name. This evidence is interpreted as showing that they expect ostensive signals to precede referential information. The present study tested chimpanzees, one of the closest relatives to humans, in a series of eye-tracking experiments using an experimental design adapted from these previous studies. In the ostension conditions, a human actor made eye contact, called the participant's name, and then looked at one of two objects. In the control conditions, a salient cue, which differed in each experiment (a colorful object, the actor's nodding, or an eating action), attracted participants' attention to the actor's face, and then the actor looked at the object. Overall, chimpanzees followed the actor's gaze to the cued object in both ostension and control conditions, and the ostensive signals did not enhance gaze following more than the control attention-getters. However, the ostensive signals enhanced subsequent attention to both target and distractor objects (but not to the actor's face) more strongly than the control attention-getters-especially in the chimpanzees who had a close relationship with human caregivers. We interpret this as showing that chimpanzees have a simple form of communicative expectations on the basis of ostensive signals, but unlike human infants and dogs, they do not subsequently use the experimenter's gaze to infer the intended referent. These results may reflect a limitation of non-domesticated species for interpreting humans' ostensive signals in inter-species communication.
... When compared to wolves, dogs' closest relative, they, again, show a better understanding of human communicative gestures (62). With training and intense socialization, wolves can, however, successfully follow human referential cues (65)(66)(67). Other species, both domesticated and captive wild species, have been tested in the object-choice paradigm. ...
... Although dogs effectively engage with humans as cooperative partners in a variety of contexts, researchers have proposed alternative explanations regarding the phylogenetic origins and potential adaptive significance of these abilities (G acsi et al., 2009;Hare & Tomasello, 2005a, 2005bRange & Vir anyi, 2015;Wynne, 2021). Whereas some researchers argue that inherited social skills from a common ancestor with wolves can account for dogs' interspecific cooperative communicative skill (Lampe et al., 2017;Range et al., 2019;Udell et al., 2012;Vir anyi et al., 2008), others hypothesize that domestication altered dog social cognition to enable new forms of cooperation and communication with humans Hare et al., 2002;Hare & Tomasello, 2005a, 2005bSalomons et al., 2021). Under the latter account, selection against fear and aggression towards humans was a key initial stage of dog domestication (Hare, 2017;Hare & Woods, 2020), opening a niche in which sensitivity to human communication and motivation to cooperate with humans may have become adaptive (possibly involving selection for interest in humans as social partners). ...
Article
Hypotheses regarding the evolution of uniquely human social cognition often emphasize not only mental state representation, but also mental state sharing. Mental state sharing is evident in instances of joint intentionality – mutual understanding between individuals of each other's simultaneous and interdependent commitment to a shared activity or goal. Comparative studies supporting the human uniqueness of joint intentionality show that, as compared to human children, chimpanzees, Pan troglodytes, who engage with humans as cooperative partners do not altruistically help others achieve their goals across the same range of contexts, do not attempt to re-engage cooperative partners in problem-solving or social games at the same rate and do not show spontaneous role reversal. Although recent work supports the possibility that bonobos, Pan paniscus, may re-engage conspecific partners after interrupted social grooming, the extent to which other animals show similar behaviour across more diverse contexts remains largely unexplored. Domestic dogs', Canis familiaris, propensity to interact with humans in cooperative contexts makes them a potentially promising comparative model of prosocial mental state sharing. Here, we investigated a behavioural signature of joint intentionality during social play between humans and dogs (N = 82). Our results present the first experimental evidence of re-engagement behaviour in dogs, as dogs preferentially attempted to reinitiate an interrupted social game with their previous partner relative to a passive bystander. These findings suggest that dogs exhibit a key marker of joint intentionality and open the door for future research on the cognitive mechanisms supporting this behaviour.
... Bogná r et al. 64,82 and Gá csi et al. 83 ), but we found no significant correlations with either factor. In future studies, domestication-related effects could be tested by comparing modern versus ancient breeds (differing in genetic ancestry 84 ) or similarly socialized wolves versus dogs [85][86][87][88] with comparable speech exposure. ...
Article
To learn words, humans extract statistical regularities from speech. Multiple species use statistical learning also to process speech, but the neural underpinnings of speech segmentation in non-humans remain largely unknown. Here, we investigated computational and neural markers of speech segmentation in dogs, a phylogenetically distant mammal that efficiently navigates humans’ social and linguistic environment. Using electroencephalography (EEG), we compared event-related responses (ERPs) for artificial words previously presented in a continuous speech stream with different distributional statistics. Results revealed an early effect (220–470 ms) of transitional probability and a late component (590–790 ms) modulated by both word frequency and transitional probability. Using fMRI, we searched for brain regions sensitive to statistical regularities in speech. Structured speech elicited lower activity in the basal ganglia, a region involved in sequence learning, and repetition enhancement in the auditory cortex. Speech segmentation in dogs, similar to that of humans, involves complex computations, engaging both domain-general and modality-specific brain areas. Video abstract https://www.cell.com/cms/asset/7a042297-f9c6-4fd4-bdd9-af1d5f2b201f/mmc4.mp4 Loading ... (mp4, 28.68 MB) Download video
... We assay canid eye-contact and sociability with humans in a four-phase study (Jakovcevic et al. 2012;vonHoldt et al. 2017). Canid eye-contact and duration have been studied in a variety of scenarios with animals, including the detour task (Pongracz et al. 2005), object choice paradigm (Viranyi et al. 2008), and unsolvable task studies (Miklosi et al. 2003). Domestic dogs are expected to initiate and extend eye-contact, be sociable to both unfamiliar and familiar people and respond positively to active engagement (Gacsi et al. 2004;Miklosi et al. 2007;Udell and Wynne 2008;Udell et al. 2011). ...
Article
Full-text available
Dogs were the first animal to become domesticated by humans, and they represent a classic model system for unravelling the processes of domestication. We compare Australian dingo eye-contact and socialization with Basenji and German Shepherd dog (GSD) breeds. Australian dingoes arrived in Australia 5,000-8,000BP, and there is debate whether they were domesticated before their arrival. The Basenji represents a primitive breed that diverged from the remaining breeds early in the domestication process, while GSDs are a breed dog selected from existing domestic dogs in the late 1800 s. We conducted a 4-phase study with unfamiliar and familiar investigators either sitting passively or actively calling each canid. We found 75% of dingoes made eye-contact in each phase. In contrast, 86% of Basenjis and 96% of GSDs made eye-contact. Dingoes also exhibited shorter eye-gaze duration than breed dogs and did not respond to their name being called actively. Sociability, quantified as a canid coming within 1 m of the experimenter, was lowest for dingoes and highest for GSDs. For sociability duration, dingoes spent less time within 1 m of the experimenter than either breed dog. When compared to previous studies, these data show the dingo is behaviorally intermediate between wild wolves and Basenji dogs and suggests it was not domesticated before it arrived in Australia. However, it remains possible that the accumulation of mutations since colonization has obscured historical behaviors, and dingoes now exist in a feralized re-tamed cycle. Additional morphological and genetic data are required to resolve this conundrum.
... For example, even New Guinea singing dogs and dingoes, who have not been under intense artificial selection, are skilled at understanding human gestures when searching Smith and Litchfield 2010). Like chimpanzees, some adult wolves can learn to comprehend human gestures through practice and intense exposure to humans, but they do not show the early emerging skills observed in dog puppies (Gácsi et al. 2009;Udell et al. 2012;Lampe et al. 2017;Virányi et al. 2008). In a recent comparison, dozens of wolf puppies were hand-reared from 10 days after birth and exposed to humans 24 h a day (i.e. they slept together with their caregivers). ...
Article
Full-text available
Dogs’ special relationship with humans not only makes them ubiquitous in our lives, but working dogs specifically perform essential functions for us such as sniffing out bombs and pulling wheelchairs for the disabled. To enhance the performance of working dogs, it is essential to understand the cognitive skills that underlie and lead to their success. This review details recent work in the field of canine cognition, including how dogs have evolved socio-cognitive skills that mimic or, in some cases, rival even our closest primate relatives. We review how these findings have laid the foundation for new studies that hope to help enhance working dog programs. This includes work that has begun to reveal the development and stability of the most important traits for service work. Discoveries like these suggest the possibility of translating what we have learned to improve breeding, selection, and training for these jobs. The latest research we review here shows promise in contributing to the production of better dogs and, consequently, more help for people.
... Our findings are of particular interest in the context of dog-wolf differences, as previous studies suggest that communication, inhibitory control, and physical reasoning are cognitive domains in which dog and wolf cognition may differ. With respect to communication, many studies suggest that dogs are biologically prepared (Cummins and Cummins 1999) to communicate with humans cooperatively and flexibly in ways that wolves are not (Hare et al. 2002(Hare et al. , 2010Miklósi et al. 2003;Riedel et al. 2008;Virányi et al. 2008). In contrast, a growing body of evidence suggests that wolves outperform dogs on a variety of tasks related to reasoning about causal properties of the physical world (Frank and Frank 1982;Hiestand 2011;Range et al. 2014;Lampe et al. 2017). ...
Article
Full-text available
Trait heritability is necessary for evolution by both natural and artificial selection, yet we know little about the heritability of cognitive traits. Domestic dogs are a valuable study system for questions regarding the evolution of phenotypic diversity due to their extraordinary intraspecific variation. While previous studies have investigated morphological and behavioral variation across dog breeds, few studies have systematically assessed breed differences in cognition. We integrated data from Dognition.com—a citizen science project on dog cognition—with breed-averaged genetic data from published sources to estimate the among-breed heritability of cognitive traits using mixed models. The resulting dataset included 11 cognitive measures for 1508 adult dogs across 36 breeds. A factor analysis yielded four factors interpreted as reflecting inhibitory control, communication, memory, and physical reasoning. Narrow-sense among-breed heritability estimates—reflecting the proportion of cognitive variance attributable to additive genetic variation—revealed that scores on the inhibitory control and communication factors were highly heritable (inhibitory control: h2 = 0.70; communication: h2 = 0.39), while memory and physical reasoning were less heritable (memory: h2 = 0.17; physical reasoning: h2 = 0.21). Although the heritability of inhibitory control is partially explained by body weight, controlling for breed-average weight still yields a high heritability estimate (h2 = 0.50), while other factors are minimally affected. Our results indicate that cognitive phenotypes in dogs covary with breed relatedness and suggest that cognitive traits have strong potential to undergo selection. The highest heritabilities were observed for inhibitory control and communication, both of which are hypothesized to have been altered by domestication.
... Studies of these canids provide a mechanism to explore the evolutionary nature of responsiveness to human gestures and how it is influenced by domestication. Research on both captive wolves with limited human socialization and on hand-reared and highly socialized wolves give conflicting results on the ability of wolves to outperform dogs (Miklósi et al. 2003;Virányi et al. 2008;Hare et al. 2010;Udell et al. 2012). Those studies demonstrating success have been hypothesized to be linked to acceptance of humans as social companions by individual wolves (Udell et al. 2010;Heberlein et al. 2016). ...
Article
Full-text available
Interspecific communication is often studied by determining a species ability to respond to human gestures. Results emerging from pet versus free-roaming domestic dogs (Canis familiaris) elucidate differences in the behavioral changes that occur based on life experience and human socialization in the development of social cognition. Additional research on wild species of canids raised with minimal levels of human socialization may provide insight into the importance of human socialization in the ability of non-human animals to correctly respond to a human gesture. We used captive coyotes (Canis latrans) to test whether coyotes could use human pointing gestures to succeed in an object-choice task. We specifically tested two groups of coyotes; both were minimal human socialization but one group was coyote-reared while the other group had high levels of human socialization during early ontogenetic development because they were hand-reared until 12 weeks of age. We tested 12 coyotes (n = 5 hand-reared, n = 7 coyote-reared) on responses to a human distal-pointing gesture across 10 trials each. Only one coyote, a hand-reared male, performed better than expected by chance and made correct choices in eight trials (incorrect choices in trials three and four). We found no difference between coyote-or hand-reared coyotes in their abilities to respond correctly to a human distal-pointing gesture (t =-0.043, P = 0.97). Performance did not improve over time among all coyotes or within either group. The preliminary results from this study suggest that most coyotes will not respond to human gestures and early life experience does not appear to improve adult performance. These findings are in contrast to most studies of gesture studies of canids.
... Comparable studies with human-socialized wolves are essentially lacking: Topál et al. (2005) found that, unlike 16 weeks old dogs, 16 weeks old hand-reared wolves did not show a preference for a human caretaker in an Ainsworth's strange situation test. However, these wolves were not intensively in contact with their caretaker at the period the test was conducted (Virányi et al., 2008). Hence, as the wolves' and dogs' socialization substantially differed between research groups, results are hard to compare. ...
Article
Full-text available
Due to domestication, dogs differ from wolves in the way they respond to their environment, including to humans. Selection for tameness and the associated changes to the autonomic nervous system (ANS) regulation have been proposed as the primary mechanisms of domestication. To test this idea, we compared two low-arousal states in equally raised and kept wolves and dogs: resting, a state close to being asleep, and inactive wakefulness, which together take up an important part in the time budgets of wolves and dogs. We measured arousal via cardiac output in three conditions: alone, with a familiar human partner, or with pack members (i.e., conspecifics). Specifically, we compared heart rate (HR) and heart rate variability (HRV) of six wolves and seven dogs. As patterns of resting can vary adaptively, even between closely related species, we predicted that dogs would be generally more aroused than wolves, because living with humans may come with less predictable contexts than living with conspecifics; hence, dogs would need to be responsive at all times. Furthermore, we predicted that due to the effects of domestication, emotional social support by familiar people would reduce arousal more in dogs than in equally human-socialized wolves, leading to more relaxed dogs than wolves when away from the pack. Overall, we found a clear effect of the interactions between species (i.e., wolf versus dog), arousal state (i.e., resting or awake inactive) and test conditions, on both HR and HRV. Wolves and dogs were more aroused when alone (i.e., higher HR and lower HRV) than when in the presence of conspecifics or a familiar human partner. Dogs were more relaxed than wolves when at rest and close to a familiar human but this difference disappeared when awake. In conclusion, instead of the expected distinct overall differences between wolves and dogs in ANS regulation, we rather found subtle context-specific responses, suggesting that such details are important in understanding the domestication process.
... The findings from this study contribute to the debate in the literature about the evolution of social skills in dogs. In line with several prior studies (Agnetta et al. 2000; al. 2009a, b;Hare et al. 2002;Kaminski et al. 2012;Riedel et al. 2008;Rossano et al. 2014;Virányi et al. 2008), our data suggest that dogs are attuned to human communicative gestures from early in development, prior to extensive exposure to humans, as they reliably follow both conventional and novel gestures to find a food reward at above chance levels (while failing to do so in the absence of any social cues). We also find that these abilities improve over time, with adult dogs exhibiting small (arm pointing: Cohen's d = 0.30) to medium (communicative marker: Cohen's d = 0.66) increases in gesture following ability. ...
Article
Full-text available
** Full-text view-only SharedIt link: https://rdcu.be/b9o1a ** While our understanding of adult dog cognition has grown considerably over the past 20 years, relatively little is known about the ontogeny of dog cognition. To assess the development and longitudinal stability of cognitive traits in dogs, we administered a battery of tasks to 160 candidate assistance dogs at 2 timepoints. The tasks were designed to measure diverse aspects of cognition, ranging from executive function (e.g., inhibitory control, reversal learning, memory) to sensory discrimination (e.g., vision, audition, olfaction) to social interaction with humans. Subjects first participated as 8–10-week-old puppies, and then were retested on the same tasks at ~ 21 months of age. With few exceptions, task performance improved with age, with the largest effects observed for measures of executive function and social gaze. Results also indicated that individual differences were both early emerging and enduring; for example, social attention to humans, use of human communicative signals, independent persistence at a problem, odor discrimination, and inhibitory control all exhibited moderate levels of rank-order stability between the two timepoints. Using multiple regression, we found that young adult performance on many cognitive tasks could be predicted from a set of cognitive measures collected in early development. Our findings contribute to knowledge about changes in dog cognition across early development as well as the origins and developmental stability of individual differences.
... Recent studies have revealed that dogs have a remarkable capacity to interact and communicate with humans that allow them to socially learn from humans a broad range of behaviour (for a review see, Miklósi and Topál, 2012). For instance, dogs spontaneously initialise communicative interactions with humans, using eye contact, gaze alternation and visual orientation (Miklósi et al., 2003;Virányi et al., 2008). They can take into account the visual perspective of a human when fetching an object (Kaminski et al., 2009). ...
Article
Full-text available
In the study of animal behaviour, culture is often seen as the result of direct social transmission from a model to a conspecific. In this essay, we show that unrecognised cultural phenomena are sustained by a special form of indirect social learning (ISL). ISL occurs when an individual B learns a behaviour from an individual A through something produced by A. A’s behavioural products can be chemicals, artefacts, but also, we argue, behaviours of another group or species that are the consequence of A’s actions. For instance, a behaviour—guiding a blind person—can be transmitted from dog A to dog B, because the fact that dog A learns the behaviour creates in the mind of the trainer representations about the efficacy of the training practice that can be transmitted to another human, who can then train dog B. These dog behaviours have all the properties of standard cultural behaviours and spread in some dog populations through the exploitation of the social learning capacities of another group/species. Following this idea requires a change in perspective on how we see the social transmission of behaviours and brings forward the fact that certain cultural practices can spread among animals through a cultural co-evolutionary dynamic with humans or other animals.
Article
The saying "A dog (Canis familiaris) is man's best friend" and the term Jinba ittai (describing the connection between a horse [Equus caballus] and a human) express the affinitive interactions between humans and these animals. In this paper regarding psychology of learning, these interspecies interactions were considered to indicate that human behaviors change behaviors of these animals and vice versa. Such mutual influence is possible because humans and these animals have innate cognitive systems that allow them to process each other's behaviors, and because humans and these animals learn each other's behaviors. Thus, studies that investigated these cognitive systems and such learning were reviewed. Next, we looked at studies that examined these interspecies interactions during rearing or training. Finally, the reason why humans not only feel that dogs and horses can interact with them but also experience affinitive relationships with these animals was discussed. The innate and learned factors involved in the construction of these relationships were considered.
Article
Full-text available
Dogs live in 45% of households, integrated into various human groups in various societies. This is certainly not true for wolves. We suggest that dogs' increased tractability (meant as individual dogs being easier to control, handle and direct by humans, in contrast to trainability defined as performance increase due to training) makes a crucial contribution to this fundamental difference. In this study, we assessed the development of tractability in hand-raised wolves and similarly raised dogs. We combined a variety of behavioural tests: fetching, calling, obeying a sit signal, hair brushing and walking in a muzzle. Wolf (N = 16) and dog (N = 11) pups were tested repeatedly, between the ages of 3-24 weeks. In addition to hand-raised wolves and dogs, we also tested mother-raised family dogs (N = 12) for fetching and calling. Our results show that despite intensive socialization, wolves remained less tractable than dogs, especially in contexts involving access to a resource. Dogs' tractability appeared to be less context dependent, as they followed human initiation of action in more contexts than wolves. We found no evidence that different rearing conditions (i.e. intensive socialization vs. mother rearing) would affect tractability in dogs. This suggests that during domestication dogs might have been selected for increased tractability, although based on the current data we cannot exclude that the differential speed of development of dogs and wolves or the earlier relocation of wolves to live as a group explains some of the differences we found.
Preprint
Full-text available
While we know that dogs evolved from wolves through a process of domestication, it remains unclear how this process may have affected dog cognitive development. Here we tested dog (N=44) and wolf (N=37) puppies, 5-18 weeks old, on a battery of temperament and cognition tasks. Dog puppies were more attracted to humans, read human gestures more skillfully and made more eye contact with humans than wolf puppies. The two species were similarly attracted to objects and performed similarly on nonsocial measures of memory and inhibitory control. These results demonstrate the role of domestication in enhancing the cooperative communication skills of dogs through selection on attraction to humans, which altered developmental pathways.
Article
Full-text available
Object Choice Task (OCT) studies are widely used to assess the phylogenetic and ontogenetic distribution of the understanding of communicative cues, with this understanding serving as a proxy for the discernment of communicative intentions. Recent reviews have found systematic procedural and methodological differences in studies which compare performances across species on the OCT. One such difference concerns the spatial configuration of the test set-up, specifically the distances between the two containers (inter-object distance) and the subject-experimenter distance. Here, we tested dogs on two versions of the task: a central version in which the containers were in the subjects’ direct line of vision, and a peripheral version in which the position of the containers was distal to the subject. Half of the subjects were tested with a barrier in the testing environment (as nonhuman primates are tested) and the other half without. We found that dogs tested with a barrier performed significantly better in the central version and were more likely to fail to make a choice in the peripheral version. Dogs tested without a barrier showed comparable performance on the two versions. We thus failed to find support for the distraction hypothesis in dogs. We discuss potential explanations for this, highlighting how methodological differences in the presentation of the OCT can influence outcomes in studies using this paradigm.
Thesis
Full-text available
En ciertas ocasiones la cooperación requiere incurrir en un costo para beneficiar a un tercero. Uno de los mecanismos posibles para explicar este tipo de conductas aparentemente altruistas, entre no parientes, es la reciprocidad (i.e. un acto cooperativo inicial podría ser retribuido luego por el beneficiado o un tercero). Esto permitiría el establecimiento de vínculos a largo plazo, beneficiosos para todos los agentes involucrados. Como consecuencia, uno de los problemas principales es elegir a los compañeros sociales con quienes interactuar para evitar a los tramposos o no-reciprocadores. El mecanismo propuesto para realizar esta evaluación se denomina atribución de reputación. Se evaluó la habilidad evaluar la reputación de las personas de forma directa en perros domésticos. El perro se ha convertido en un modelo privilegiado para el estudio comparativo de la cognición social debido a: 1) Sus sorprendentes habilidades comunicativas interespecíficas, 2) su historia filogenética y 3) su inclusión en las sociedades humanas. Se diseñó un protocolo para evaluar la habilidad de discriminar las personas generosas o egoístas definidas como aquellas que le permiten o le niegan el acceso a la comida al perro en un contexto comunicativo. El mismo consto de dos fases. En una fase de entrenamiento un experimentador, (generoso), le señalaba un recipiente con comida al perro y luego le permitía comer. En cambio, el otro experimentador (egoísta) le señalaba el recipiente correcto, pero cuando el perro se acercaba al mismo, sacaba la comida y ostensiblemente la comía a la vista del animal. Luego, en una fase de prueba se le permitía al perro elegir a uno de los dos experimentadores. Los resultados muestran que los perros son capaces de reconocer las actitudes humanas luego de interacciones directas con las personas y esta discriminación probablemente implique el reconocimiento individual de los experimentadores. Tanto la dificultad de la tarea discriminativa (semejanza o diferencia entre los experimentadores) como la cantidad y variedad de claves presentes (verbales y gestuales) modulan la velocidad de aprendizaje en esta tarea. Asimismo, los perros con escaso contacto con los humanos, como los peros de refugio, mostraron un desempeño similar al de los de familia, si bien presentaron mayores conductas de evitación. Por último, los cachorros de entre 45 y 60 días de edad también lograron resolver la tarea aunque requirieron más entrenamiento que los adultos. Estos datos sugieren que, desde muy temprano en la ontogenia y con poco contacto previo con las personas, los perros son capaces de aprender a discriminar actitudes humanas. El conjunto de los hallazgos son discutidos en función de las diversas hipótesis respecto de los orígenes de las habilidades comunicativas entre perros y personas.
Article
To characterize the early ontogeny of dog cognition, we tested 168 domestic dog, Canis familiaris, puppies (97 females, 71 males; mean age = 9.2 weeks) in a novel test battery based on previous tasks developed and employed with adolescent and adult dogs. Our sample consisted of Labrador retrievers, golden retrievers and Labrador × golden retriever crosses from 65 different litters at Canine Companions for Independence, an organization that breeds, trains and places assistance dogs for people with disabilities. Puppies participated in a 3-day cognitive battery that consisted of 14 tasks measuring different cognitive abilities and temperament traits such as executive function (e.g. inhibitory control, reversal learning, working memory), use of social cues, sensory discriminations and reactivity to and recovery from novel situations. At 8–10 weeks of age, and despite minimal experience with humans, puppies reliably used a variety of cooperative-communicative gestures from humans. Puppies accurately remembered the location of hidden food for delays of up to 20 s, and succeeded in a variety of visual, olfactory and auditory discrimination problems. They also showed some skill at executive function tasks requiring inhibitory control and reversal learning, although they scored lower on these tasks than is typical in adulthood. Taken together, our results confirm the early emergence of sensitivity to human communication in dogs and contextualize these skills within a broad array of other cognitive abilities measured at the same stage of ontogeny.
Article
Human cognition is believed to be unique in part because of early-emerging social skills for cooperative communication.¹ Comparative studies show that at 2.5 years old, children reason about the physical world similarly to other great apes, yet already possess cognitive skills for cooperative communication far exceeding those in our closest primate relatives.²,³ A growing body of research indicates that domestic dogs exhibit functional similarities to human children in their sensitivity to cooperative-communicative acts. From early in development, dogs flexibly respond to diverse forms of cooperative gestures.⁴,⁵ Like human children, dogs are sensitive to ostensive signals marking gestures as communicative, as well as contextual factors needed for inferences about these communicative acts.6, 7, 8 However, key questions about potential biological bases for these abilities remain untested. To investigate their developmental and genetic origins, we tested 375 8-week-old dog puppies on a battery of social-cognitive measures. We hypothesized that if dogs’ skills for cooperating with humans are biologically prepared, then they should emerge robustly in early development, not require extensive socialization or learning, and exhibit heritable variation. Puppies were highly skillful at using diverse human gestures, and we found no evidence that their performance required learning. Critically, over 40% of the variation in dogs’ point-following abilities and attention to human faces was attributable to genetic factors. Our results suggest that these social skills in dogs emerge early in development and are under strong genetic control.
Article
Although we know that dogs evolved from wolves, it remains unclear how domestication affected dog cognition. One hypothesis suggests dog domestication altered social maturation by a process of selecting for an attraction to humans.1, 2, 3 Under this account, dogs became more flexible in using inherited skills to cooperatively communicate with a new social partner that was previously feared and expressed these unusual social skills early in development.4, 5, 6 Here, we comparedog (n = 44) and wolf (n = 37) puppies, 5–18 weeks old, on a battery of temperament and cognition tasks. We find that dog puppies are more attracted to humans, read human gestures more skillfully, and make more eye contact with humans than wolf puppies. The two species are similarly attracted to familiar objects and perform similarly on non-social measures of memory and inhibitory control. These results are consistent with the idea that domestication enhanced the cooperative-communicative abilities of dogs as selection for attraction to humans altered social maturation.
Book
Full-text available
Whilst humans undisputedly shape and transform most of earth's habitats, the number of animals (domestic and wild) living on this planet far outnumbers that of humans. Inevitably, humans have to interact with animals under a variety of circumstances, such as during conservation efforts, wildlife and zoo management, livestock husbandry, and pet keeping. Next to the question of how humans deal with these interactions and conflicts, it is crucial to understand the animal's point of view: How do animals perceive and differentiate between humans? How do they generalize their behavior towards humans? And how does knowledge about humans spread socially? In this Research Topic, we aim to collect original empirical work and review articles to get a more comprehensive and diverse picture on how humans are part of the sensory and cognitive world of non-human animals. We strongly invite contributions that pinpoint shortcomings and limitations in interpreting the available research findings, that provide new cross-disciplinary frameworks (e.g. links between conservation biology and comparative psychology, or human-animal interactions at zoos and animal welfare) and that discuss the applied implementation of these findings (e.g. for conservation attempts or livestock husbandry management).
Article
Full-text available
This review focuses on wolf sociobiology to delineate the traits of cooperative baggage driven by natural selection (wolf-wolf cooperation) and better understand the changes obtained by artificial selection (dog-human cooperation). We selected some behaviors of the dog’s ancestors that provide the basis for the expression of a cooperative society, such as dominance relationships, leverage power, post-aggressive strategies, and playful dynamics between pack members. When possible, we tried to compare the data on wolves with those coming from the dog literature. Wolves can negotiate commodities when the interacting subjects occupy different ranking positions by bargaining social tolerance with helping and support. They are able to manage group disruption by engaging in sophisticated post-conflict maneuvers, thus restoring the relationship between the opponents and reducing the spreading of aggression in the group. Wolves engage in social play also as adults to manipulate social relationships. They are able to flexibly adjust their playful interactions to minimize the risk of escalation. Complex cognitive abilities and communicative skills are probably the main proximate causes for the evolution of inter-specific cooperation in wolves.
Article
Based on claims that dogs are less aggressive and show more sophisticated socio-cognitive skills compared with wolves, dog domestication has been invoked to support the idea that humans underwent a similar ‘self-domestication’ process. Here, we review studies on wolf–dog differences and conclude that results do not support such claims: dogs do not show increased socio-cognitive skills and they are not less aggressive than wolves. Rather, compared with wolves, dogs seek to avoid conflicts, specifically with higher ranking conspecifics and humans, and might have an increased inclination to follow rules, making them amenable social partners. These conclusions challenge the suitability of dog domestication as a model for human social evolution and suggest that dogs need to be acknowledged as animals adapted to a specific socio-ecological niche as well as being shaped by human selection for specific traits.
Article
Full-text available
The ability of adolescent chimpanzees and 2- and 3-year-old children to use pointing gestures to locate hidden surprises was examined in two experiments. The results revealed that although young 2-year-old children appeared to have no difficulty extracting referential information from a pointing gesture (independent of gaze or distance cues) and spontaneously using it to search in specific locations, adolescent chimpanzees appeared to rely on cueconfiguration and distance-based rules. Thus, although these chimpanzees were trained to respond appropriately to the pointing gestures of a human by searching in a particular location, this ability did not easily generalize to situations in which the distance between the pointing hand and the location were more distal. Furthermore, even those chimpanzees that were able to generalize in this fashion appeared to use distance-based cues, not ones based on an appreciation of the internal attentional focus or mental referent of the experimenter as indicated by his pointing gesture.
Article
Full-text available
Since the observations of O. Pfungst the use of human-provided cues by animals has been well-known in the behavioural sciences ("Clever Hans effect"). It has recently been shown that rhesus monkeys (Macaca mulatta) are unable to use the direction of gazing by the experimenter as a cue for finding food, although after some training they learned to respond to pointing by hand. Direction of gaze is used by chimpanzees, however. Dogs (Canis familiaris) are believed to be sensitive to human gestural communication but their ability has never been formally tested. In three experiments we examined whether dogs can respond to cues given by humans. We found that dogs are able to utilize pointing, bowing, nodding, head-turning and glancing gestures of humans as cues for finding hidden food. Dogs were also able to generalize from one person (owner) to another familiar person (experimenter) in using the same gestures as cues. Baseline trials were run to test the possibility that odour cues alone could be responsible for the dogs' performance. During training individual performance showed limited variability, probably because some dogs already "knew" some of the cues from their earlier experiences with humans. We suggest that the phenomenon of dogs responding to cues given by humans is better analysed as a case of interspecific communication than in terms of discrimination learning.
Chapter
Full-text available
The last 20-30 years have seen two “scientific revolutions” in the study of animal behavior: the cognitive revolution that originated in psychology, and the Darwinian, behavioral ecology revolution that originated in biology. Among psychologists, the cognitive revolution has had enormous impact. Similarly, among biologists, the Darwinian revolution has had enormous impact. The major theme of this chapter is that these two scientific research programs need to be combined into a single approach, simultaneously cognitive and Darwinian, and that this single approach is most appropriately called cognitive ethology.
Article
Full-text available
In this paper we present evidence that simple problem solving in the dog is strongly influenced by the relationship with the owner. Twenty-eight dog-owner pairs were observed in a novel situation and when performing a simple problem-solving task. Dogs were categorized according to their relationship with the owners (“companionship” or “working relationship”). In addition to the behavioral analysis of the dogs, the anthropomorphic attitudes of the owners were assessed by a questionnaire. Factor analysis showed two factors of correlated behavioral variables (“social dependence,” “social play”) of the dogs that referred to the dog-human relationship. Dogs in a companion relationship behaved socially dependently, showing a decreased performance in the problem solving task and were viewed more anthropomorphically by the owners. Results suggest that the dogs' decreased problem-solving performance is less dependent on their cognitive abilities; instead the strong, dependent relationship with the owner prevents them from completing the task successfully. On the basis of our results, we argue that the decreased problem solving ability in the domestic dog is not due to their domestication but their strong attachment to humans.
Article
Full-text available
Found that 7 hand-reared wolves performed better than 4 Alaskan malamutes and maternally-reared wolves on Wisconsin General Test Apparatus (WGTA) measures of oddity learning. Differences between the 2 groups of wolves are interpreted as motivational. Differences between the hand-reared wolves and the malamutes contradict predictions that dogs should perform better than wolves on training tasks and suggest that the WGTA tasks are amenable to either trial-and-error (associative) solutions typical of training-task performance or complex cognitive (insight) solutions more typically observed in problem-solving performance. Results confirm that insightful solutions produce more rapid acquisition and that wolf performance exhibits more insight. (PsycINFO Database Record (c) 2012 APA, all rights reserved)
Article
Full-text available
The process of domestication involves adaptation, usually to a captive environment. Domesti-cation is attained by some combination of genetic changes occurring over generations and Ž . developmental mechanisms e.g., physical maturation, learning triggered by recurring environ-mental events or management practices in captivity that influence specific biological traits. The transition from free-living to captive status is often accompanied by changes in availability andror accessibility of shelter, space, food and water, and by changes in predation and the social environment. These changes set the stage for the development of the domestic phenotype. Behavioral development in animals undergoing domestication is characterized by changes in the quantitative rather than qualitative nature of responses. The hypothesized loss of certain behavior patterns under domestication can usually be explained by the heightening of response thresholds. Increases in response frequency accompanying domestication can often be explained by atypical rates of exposure to certain forms of perceptual and locomotor stimulation. Genetic changes influencing the development of the domestic phenotype result from inbreeding, genetic drift, artificial selection, natural selection in captivity, and relaxed selection. Experiential contributions to the domestic phenotype include the presence or absence of key stimuli, changes in intraspecific aggressive interactions and interactions with humans. Man's role as a buffer between the animal and its environment is also believed to have an important effect on the development of the domestic phenotype. The domestication process has frequently reduced the sensitivity of animals to changes in their environment, perhaps the single-most important change accompanying domestication. It has also resulted in modified rates of behavioral and physical development. Interest in breeding animals in captivity for release in nature has flourished in recent decades. The capacity of domestic animals to survive and reproduce in nature may depend on the extent to which the gene pool of the population has been altered during the domestication process and flexibility in behavioral development. ''Natural'' gene pools should be protected when breeding wild animals in captivity for the purpose of reestablishing free-living natural populations. In some) Tel.
Article
Full-text available
In this review, we assess the current state of knowledge on domestication of the major livestock species. We present first some historical background on location and dates of domestication of livestock. The characteristics that favoured domestication are described, especially gregariousness, precocity of young and diet. We then describe the genetic processes involved during domestication, i.e. uncontrolled processes such as inbreeding and genetic drift, partially controlled processes such as relaxation of natural selection and natural selection in captivity and controlled processes such as active selection. Details are also given on how the resource allocation theory explains changes occurring during domestication. The methods used to assess the extent to which domestication has changed animals (comparisons of wild and domestic stocks, longitudinal analysis and molecular genetics) are also listed. Finally, major behavioural modifications observed during domestication are described, including relationships with humans and predators, and social, feeding, reproductive and maternal behaviours as well as morphological changes.
Article
Full-text available
A theoretical model proposed by the first author (Frank 1980) hypothesizes that timber wolves (Canis lupus) should perform better than dogs (C. familiaris) on problem-solving tasks requiring ‘insight’, such as the detour test devised by Kohler (1927) and adapted by Scott & Fuller (1965) for use with 6-week-old domestic dog pups. Three barrier problems (short barrier, long barrier, and U-barrier) were administered to four 6-week-old Eastern wolf (C. l. lycaon) pups. Post hoc comparisons with results obtained by Scott & Fuller confirm the hypothesis.
Article
Full-text available
On the basis of a study by D. J. Povinelli, D. T. Bierschwale, and C. G. Cech (1999), the performance of family dogs (Canis familiaris) was examined in a 2-way food choice task in which 4 types of directional cues were given by the experimenter: pointing and gazing, head-nodding ("at target"), head turning above the correct container ("above target"), and glancing only ("eyes only"). The results showed that the performance of the dogs resembled more closely that of the children in D. J. Povinelli et al.'s study, in contrast to the chimpanzees' performance in the same study. It seems that dogs, like children, interpret the test situation as being a form of communication. The hypothesis is that this similarity is attributable to the social experience and acquired social routines in dogs because they spend more time in close contact with humans than apes do, and as a result dogs are probably more experienced in the recognition of human gestures.
Article
Full-text available
In a series of 3 experiments, dogs (Canis familiaris) were presented with variations of the human pointing gesture: gestures with reversed direction of movement, cross-pointing, and different arm extensions. Dogs performed at above chance level if they could see the hand (and index finger) protruding from the human body contour. If these minimum requirements were not accessible, dogs still could rely on the body position of the signaler. The direction of movement of the pointing arm did not influence the performance. In summary, these observations suggest that dogs are able to rely on relatively novel gestural forms of the human communicative pointing gesture and that they are able to comprehend to some extent the referential nature of human pointing.
Article
Full-text available
Dogs are more skillful than great apes at a number of tasks in which they must read human communicative signals indicating the location of hidden food. In this study, we found that wolves who were raised by humans do not show these same skills, whereas domestic dog puppies only a few weeks old, even those that have had little human contact, do show these skills. These findings suggest that during the process of domestication, dogs have been selected for a set of social-cognitive abilities that enable them to communicate with humans in unique ways.
Article
Full-text available
The authors tested 2 bottlenosed dolphins (Tursiops truncatus) for their understanding of human-directed gazing or pointing in a 2-alternative object-choice task. A dolphin watched a human informant either gazing at or pointing toward 1 of 2 laterally placed objects and was required to perform a previously indicated action to that object. Both static and dynamic gaze, as well as static and dynamic direct points and cross-body points, yielded errorless or nearly errorless performance. Gaze with the informant's torso obscured (only the head was shown) produced no performance decrement, but gaze with eyes only resulted in chance performance. The results revealed spontaneous understanding of human gaze accomplished through head orientation, with or without the human informant's eyes obscured, and demonstrated that gaze-directed cues were as effective as point-directed cues in the object-choice task.
Article
Full-text available
Dogs' (Canis familiaris) and cats' (Felis catus) interspecific communicative behavior toward humans was investigated. In Experiment 1, the ability of dogs and cats to use human pointing gestures in an object-choice task was compared using 4 types of pointing cues differing in distance between the signaled object and the end of the fingertip and in visibility duration of the given signal. Using these gestures, both dogs and cats were able to find the hidden food; there was no significant difference in their performance. In Experiment 2, the hidden food was made inaccessible to the subjects to determine whether they could indicate the place of the hidden food to a naive owner. Cats lacked some components of attention-getting behavior compared with dogs. The results suggest that individual familiarization with pointing gestures ensures high-level performance in the presence of such gestures; however, species-specific differences could cause differences in signaling toward the human.
Article
Full-text available
We review studies demonstrating the ability of some animals to understand the human pointing gesture. We present a 3-step analysis of the topic. (1) We compare and evaluate current experimental methods (2) We compare available experimental results on performance of different species and investigate the interaction of species differences and other independent variables (3) We evaluate how our present understanding of pointing comprehension answers questions about function, evolution and mechanisms. Recently, a number of different hypotheses have been put forward to account for the presence of this ability in some species and for the lack of such comprehension in others. In our view, there is no convincing evidence for the assumption that the competitive lifestyles of apes would inhibit the utilization of this human gesture. Similarly, domestication as a special evolutionary factor in the case of some species falls short in explaining high levels of pointing comprehension in some non-domestic species. We also disagree with the simplistic view of describing the phenomenon as a simple form of conditioning. We suggest that a more systematic comparative research is needed to understand the emerging communicative representational abilities in animals that provide the background for comprehending the human pointing gesture.
Article
Full-text available
Twenty domestic horses (Equus caballus) were tested for their ability to rely on different human gesticular cues in a two-way object choice task. An experimenter hid food under one of two bowls and after baiting, indicated the location of the food to the subjects by using one of four different cues. Horses could locate the hidden reward on the basis of the distal dynamic-sustained, proximal momentary and proximal dynamic-sustained pointing gestures but failed to perform above chance level when the experimenter performed a distal momentary pointing gesture. The results revealed that horses could rely spontaneously on those cues that could have a stimulus or local enhancement effect, but the possible comprehension of the distal momentary pointing remained unclear. The results are discussed with reference to the involvement of various factors such as predisposition to read human visual cues, the effect of domestication and extensive social experience and the nature of the gesture used by the experimenter in comparative investigations.
Article
This chaper is about the origins and significance of an apparently simple behavior - looking into the eyes of other people. In this chapter the author suggests a theoretical framework for interpreting the significance of eye contact in humans Homo sapiens, and then explores its occurrence in nonhuman primates. The author suggests that eye contact in humans is a case of 'ostensive behaviour' - that is, a way to express and assess communicative intent - and, as such, an important sign of higher cognitive processes. He then explores a purported behavioral difference between monkeys and apes - their reactions to eye contact - and to what extent it reflects an important difference in cognition and communication. The author concludes that the great apes seem to be capable of some sort of ostensive function by means of eye contact. The problem of ostension is closely related to that of mind-reading or theory of mind. Ostension through eye contact seems to involve some mechanisms close to what have been described as theory of mind and it could give us a clue as to the origins of this complex cognitive ability.
Article
Le complexe du comportement humain est l'ensemble des caracteristiques et des proprietes qui definissent specifiquement l'Homo Sapiens. Les changements biologiques de ces caracteristiques sont apparus au cours de l'evolution humaine comme une consequence de la compulsion de la communication du fait de l'accroissement de la densite de la population et des relations interculturelles. La communication humaine est a la fois le produit et le facteur de l'evolution humaine ; son origine peut etre etudiee seulement en prenant en compte cette double nature.
Article
Observations on the behavioral development of a male timber wolf, hand-reared from the age of four weeks, have been continued for a period of three years. Data include the following: (1) Adjustment to human companionship has been successful even after sexual maturity. (2) Behavior towards strange persons and objects is cautious. (3) The animal remains more independent and aloof to persons than similarly reared dogs. (4) Interaction with dogs, including males and young puppies, is marked by gregariousness and lack of aggression. (5) Small domestic species have been attacked occasionally, the response depending largely upon the behavior of these animals. (6) Large species are avoided, chased, or ignored. (7) Numerous motor patterns, postures, and communicative signals are closely similar to siblings and other wolves and contrast with dog companions. (8) Sharp behavioral changes occurred at eight and 12 weeks, the former initiating aggressive tendencies, the latter extreme avoidance in the presence of new objects. Restlessness, then calming, followed in later months, and slight seasonal fluctuations have been noted. (9) Rudiments of many adult motor patterns occurred at an early age, e.g., small prey-pounces and pelvic thrusts seen by eight weeks. (10) Vocalizations include a wide repertoire of howls, squeaks, growls, and barks.
Article
The present investigations were undertaken to compare interspecific communicative abilities of dogs and wolves, which were socialized to humans at comparable levels. The first study demonstrated that socialized wolves were able to locate the place of hidden food indicated by the touching and, to some extent, pointing cues provided by the familiar human experimenter, but their performance remained inferior to that of dogs. In the second study, we have found that, after undergoing training to solve a simple manipulation task, dogs that are faced with an insoluble version of the same problem look/gaze at the human, while socialized wolves do not. Based on these observations, we suggest that the key difference between dog and wolf behavior is the dogs' ability to look at the human's face. Since looking behavior has an important function in initializing and maintaining communicative interaction in human communication systems, we suppose that by positive feedback processes (both evolutionary and ontogenetically) the readiness of dogs to look at the human face has lead to complex forms of dog-human communication that cannot be achieved in wolves even after extended socialization.
Article
When cue objects are displaced as much as 6 inches vertically from the site of reward, monkeys completely failed to acquire an object-quality discrimination problem. Introduction of spatial displacement to the cue-reward relationship with animals that had previously learned resulted in reduction of stimulation to near-chance levels. Delay of reward as an explanation is discounted and spatial location is emphasized.
Article
In this study we compared the nature of the joint attentional interactions that occurred as chimpanzees and human children engaged with a human experimenter (E). Subjects were three chimpanzees raised mostly with conspecifics (mother-reared), three chimpanzees raised in a human-like cultural environment (encultur-ated), and six 18-month-old human children. Of particular interest were possible differences between the two groups of chimpanzees that might have resulted from their different ontogenetic histories. Observations were made as subjects participated in an imitative learning task involving a number of novel objects. Variables coded were such things as subjects' looks to the object, looks to E, the coordination of such looks in periods of joint engagement with E, and gestural attempts to direct E's attention or behavior (declaratives and imperatives). Results showed that encultur-ated chimpanzees were most similar to human children in social interactions involv-ing objects, for example, in their attention to the object in compliance with E's request, their joint attentional interactions during less structured periods, and their use of declarative gestures to direct E's attention to objects. They were not similar to children, but rather resembled their mother-reared conspecifics, in the duration of their looks to E's face. A positive relation between subjects' joint attentional skills and their imitative learning skills was found for both chimpanzee and human sub-jects. It is concluded that a human-like sociocultural environment is an essential component in the development of human-like social-cognitive and joint attentional skills for chimpanzees, and perhaps for human beings as well
Article
Sixteen domestic dogs (Canis familiaris) and four horses (Equus caballus) were tested for their ability to use human-given manual and facial cues in an object-choice task. Two of the four horses used touch as a cue and one horse successfully used pointing. The performance of the dogs was considerably better, with 12 subjects able to use pointing as a cue, 4 able to use head orientation and 2 able to use eye gaze alone. Group analysis showed that the dogs performed significantly better in all experimental conditions than during control trials. Dogs were able to use pointing cues even when the cuer’s body was closer to the incorrect object. Working gundogs with specialised training used pointing more successfully than pet dogs and gundog breeds performed better than non-gundog breeds. The results of this experiment suggest that animals’ use of human given communicative signals depends on cognitive ability, the evolutionary consequences of domestication and enculturation by humans within the individual’s lifetime.
Article
Despite earlier scepticism there is now evidence for simple forms of intentional and functionally referential communication in many animal species. Here we investigate whether dogs engage in functional referential communication with their owners. “Showing” is defined as a communicative action consisting of both a directional component related to an external target and an attention-getting component that directs the attention of the perceiver to the informer or sender. In our experimental situation dogs witness the hiding of a piece of food (or a favourite toy) which they cannot get access to. We asked whether dogs would engage in “showing” in the presence of their owner. To control for the motivational effects of both the owner and the food on the dogs’ behaviour, control observations were also staged where only the food (or the toy) or the owner was present. Dogs’ gazing frequency at both the food (toy) and the owner was greater when only one of these was present. In other words, dogs looked more frequently at their owner when the food (toy) was present, and they looked more at the location of the food (toy) when the owner was present. When both the food (toy) and the owner were present a new behaviour, “gaze alternation”, emerged which was defined as changing the direction of the gaze from the location of the food (toy) to looking at the owner (or vice versa) within 2 s. Vocalisations that occurred in this phase were always associated with gazing at the owner or the location of the food. This behaviour, which was specific to this situation, has also been described in chimpanzees, a gorilla and humans, and has often been interpreted as a form of functionally referential communication. Based on our observations we argue that dogs might be able to engage in functionally referential communication with their owner, and their behaviour could be described as a form of “showing”. The contribution of domestication and individual learning to the well-developed communicative skills in dogs is discussed and will be the subject of further studies.
Article
The results of three experiments are reported. In the main study, a human experimenter presented domestic dogs (Canis familiaris) with a variety of social cues intended to indicate the location of hidden food. The novel findings of this study were: (1) dogs were able to use successfully several totally novel cues in which they watched a human place a marker in front of the target location; (2) dogs were unable to use the marker by itself with no behavioral cues (suggesting that some form of human behavior directed to the target location was a necessary part of the cue); and (3) there were no significant developments in dogs’ skills in these tasks across the age range 4 months to 4 years (arguing against the necessity of extensive learning experiences with humans). In a follow-up study, dogs did not follow human gaze into “empty space” outside of the simulated foraging context. Finally, in a small pilot study, two arctic wolves (Canis lupus) were unable to use human cues to locate hidden food. These results suggest the possibility that domestic dogs have evolved an adaptive specialization for using human-produced directional cues in a goal-directed (especially foraging) context. Exactly how they understand these cues is still an open question.
Article
Three capuchin monkeys, Cebus apella, were tested on object-choice tasks in which the correct (i.e. baited) object was indicated by the experimenter during the response period on half of all trials. Three cue conditions were used in five experiments: gazing at the correct object, gazing plus pointing, and pointing alone. The subjects did not use the experimenter's gazing at the correct object as a cue. In contrast, they did use gazing plus pointing, and the final experiment showed that pointing was necessary and sufficient under the conditions of the study. The ineffectiveness of the experimenter's gazing as a cue may be caused by reduced cue-response spatial contiguity, but it may also reflect a limitation of mental or visual perspective-taking in these monkeys.
Article
Interspecific variation in learning and cognition is often accounted for by adaptive specialization, an ecological framework where variation between species in the environmental problems they face is thought to select for quantitatively and/or qualitatively different abilities. Adaptive specialization theory relies on the comparative method for testing its hypotheses and assumes a naturally selected basis for the predicted differences. This review examines social learning as a specialization to group-living and scramble feeding competition. It points out one important problem with current studies in the area, the lack of quantitative controls for confounding variables that may cause type 1 or 2 error in comparative tests. A linear regression technique is proposed to measure and remove interspecific differences on control tests for which there is no predicted adaptive specialization; as in other areas of comparative biology, the adaptive prediction is then made on the residual deviation from the regression of these confounding variables. Examples are given from research on opportunistic Columbids, the group-living feral pigeon Columbia livia, and the territorial Zenaida dove, Zenaida aurita.
Article
We recorded the behaviour of dogs in detour tests, in which an object (a favourite toy) or food was placed behind a V-shaped fence. Dogs were able to master this task; however, they did it more easily when they started from within the fence with the object placed outside it. Repeated detours starting from within the fence did not help the dogs to obtain the object more quickly if in a subsequent trial they started outside the fence with the object placed inside it. While six trials were not enough for the dogs to show significant improvement on their own in detouring the fence from outside, demonstration of this action by humans significantly improved the dogs' performance within two–three trials. Owners and strangers were equally effective as demonstrators. Our experiments show that dogs are able to rely on information provided by human action when confronted with a new task. While they did not copy the exact path of the human demonstrator, they easily adopted the detour behaviour shown by humans to reach their goal.
Article
Although dogs, Canis familiaris, are skilful at responding to human social cues, the role of ontogeny in the development of these abilities has not been systematically examined. We studied the ability of very young dog puppies to follow human communicative cues and successfully find hidden food. In the first experiment we compared 6-, 8-, 16- and 24-week-old puppies in their ability to use pointing gestures or a marker as a cue. The results showed that puppies, independent of age, could use all human communicative cues provided; only their success at using the marker cue increased with age. In the second and third experiments we investigated the flexibility of the puppies' understanding by reducing the degree to which they could use local enhancement to solve these problems. Here, subjects could not simply approach the hand of the experimenter and follow its direction to the correct location because cups were placed next to the dog instead of next to the experimenter. Six-week-old puppies readily used all of the human communicative cues provided. These findings support the hypothesis that domestication played a critical role in shaping the ability of dogs to follow human-given cues.
Article
Using the Strange Situation Test originally developed for testing the mother–infant relationship in humans, we compared the attachment behaviour of extensively socialized (hand-reared) dog, Canis familiaris, and wolf, Canis lupus, puppies towards their human caregiver with that of pet dog puppies of the same age. The experiment was designed to study whether (1) dog puppies as young as 16 weeks show attachment to a human caregiver, (2) extensive socialization by human caregivers affects attachment behaviour of dog puppies and (3) evolutionary changes (in the form of species-specific differences between wolf and dog pups) affect the emergence of dog–human attachment. We found a characteristic selective responsiveness to the owner in young dogs, similar to that observed in adults. This finding supports the view that puppies show patterns of attachment towards their owners. Extensive socialization had only a minor effect on the attachment behaviour in dog puppies, as the behaviour of pet dogs and hand-reared dogs was basically similar. However, we found a significant species-specific difference between wolves and dogs: both extensively socialized and pet dog puppies were more responsive to the owner than to an unfamiliar human participant, whereas extensively socialized wolves were not. Behavioural differences could be best explained by assuming that selective processes took place in the course of domestication (genetic changes) that are related to the attachment system of the dog.