Many faces of dominance: the manifestation of cohabiting companion dogs' rank in competitive and non-competitive scenarios

There are indications that companion dogs of multi-dog households form a hierarchy, maintained by formal and agonistic dominance. Although it was found that the behaviour of dogs depends on their rank in several contexts, so far, the assessment of their rank itself has been based on owner-completed questionnaires. With this research we endeavoured to find associations between rank scores from the Dog Rank Assessment Questionnaire (DRA-Q) and cohabiting dogs' behaviour in a competitive test (Toy Possession test-32 dog pairs) and a non-competitive, citizen science scenario (Greeting test-20 dog pairs). Based on the grabbing the toy first and keeping the toy at the end variables, the dogs' rank score provided a reliable indication of the dominant and subordinate dogs' behaviour in the Toy Possession test. Similarly, the occurrence of dominant and submissive behaviours in the Greeting Test showed a good match with the agonistic and leadership subscores of the composite rank score from the DRA-Q. Our results provide a pioneering case for validating a questionnaire-based rank scoring method with biologically meaningful behavioural tests in the case of companion dogs. The finer analysis of the results highlighted that in the case of a multi-question scoring system, some components might provide more effective prediction of the dogs' rank-related behaviour in some situations, while other components are more relevant in others, with traits related to agonistic dominance having relevance across contexts.

Spontaneous action matching in dog puppies, kittens and wolf pups

We investigated the spontaneous tendency of dog puppies, kittens and wolf pups to match their behaviour to actions demonstrated by a human, in the absence of food reward. Based on dogs' inherent sociality and domestication history, we predicted that the tendency to match human actions is more pronounced in this species than in the other two. To test this, we exposed N = 42 dog puppies, N = 39 kittens and N = 8 wolf pups to ostensive human demonstrations of an object-related action. We found that dog puppies paid more attention to the demonstration than kittens and wolf pups. Dog puppies and wolf pups matched the demonstrated actions in more trials than kittens. Dog puppies also tended to reproduce the human demonstration that differed from the action they typically preformed in the absence of demonstration. These results support that dog puppies show a tendency to attend to humans and conform their behaviour to human demonstrations in the absence of extrinsic food rewards. This spontaneous tendency is also relevant for practical applications, by providing the basis to devise puppy-training methods that rely less on food rewards, and instead exploit puppies' natural predisposition for social learning.

Cognitive-Behavioral Divergence Is Greater Across Alternative Male Reproductive Phenotypes Than Between the Sexes in a Wild Wrasse

Sexual selection is a powerful diversifier of phenotype, behavior and cognition. Here we compare cognitive-behavioral traits across four reproductive phenotypes (females and three alternative males) of wild-caught ocellated wrasse (Symphodus ocellatus). Both sex and alternative male phenotypes are environmentally determined with sex determination occuring within the first year, and males transition between alternative phenotypes across 2 years (sneaker to satellite or satellite to nesting). We captured 151 ocellated wrasse and tested them on different behavior and cognition assays (scototaxis, shoaling, and two detour-reaching tasks). We found greater divergence across alternative male reproductive phenotypes than differences between the sexes in behavior, problem-solving, and relationships between these traits. Nesting males were significantly less bold than others, while sneaker males were faster problem-solvers and the only phenotype to display a cognitive-behavioral syndrome (significant correlation between boldness and problem-solving speed). Combining these results with prior measurements of sex steroid and stress hormone across males, suggests that nesting and sneaker males represent different coping styles. Our data suggests that transitioning between alternative male phenotypes requires more than changes in physiology (size and ornamentation) and mating tactic (sneaking vs. cooperation), but also involves significant shifts in cognitive-behavioral and coping style plasticity.

Grumpy Dogs Are Smart Learners-The Association between Dog-Owner Relationship and Dogs' Performance in a Social Learning Task

We investigated how dog-owner relationship-with a focus on possible behavioural problems-might associate with the individual variability in dogs' social learning performance. Dog owners first completed a questionnaire about their relationship with their dogs (N = 98). Then, dogs were tested in a detour test: a control group without demonstration, a group where the owner demonstrated the task and another group where the experimenter demonstrated the task. Finally, the dogs participated in two behaviour tests measuring their tractability and possessiveness. The two principal components from the questionnaire (called "overactive" and "irritable") did not show significant association with dogs' detour performance in the control group. "irritable" dogs performed better in the unfamiliar demonstrator group. These more persistent, goal-oriented dogs also looked back less at their owners during the detour. In the individual problem-solving context, the factor "overactive" had a similar effect on looking back at the owner, suggesting that the items of this component primarily are not connected to the dog-human relationship. Our results indicate that dog-human relationship has an integral role in the complex social behaviour of dogs, which warrants for the need of further empirical testing of the associations between social dynamics in dogs and their relationship with humans, including problem behaviours.

Dogs (Canis familiaris) recognize their own body as a physical obstacle

Mental representations of one’s own body provide useful reference when negotiating physical environmental challenges. Body-awareness is a neuro-ontogenetic precursor for higher order self-representation, but there is a lack of an ecologically valid experimental approach to it among nonhuman species. We tested dogs (N = 32) in the ‘body as an obstacle’ task. They had to pick up and give an object to their owner, whilst standing on a small mat. In the test condition we attached the object to the mat, thus the dogs had to leave the mat because otherwise they could not lift the object. Dogs came off the mat more frequently and sooner in the test condition, than in the main control condition, where the object was attached to the ground. This is the first convincing evidence of body awareness through the understanding of the consequence of own actions in a species where previously no higher-order self-representation capacity was found. We urge for an ecologically valid approach, and following of bottom-up methods, in studying modularly constructed self-representation.

How Dogs Perceive Humans and How Humans Should Treat Their Pet Dogs: Linking Cognition With Ethics

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.

Selective overimitation in dogs

Dogs have not only shown different kinds of social learning, from either conspecifics or humans, including do-as-I-do imitation, deferred imitation, and selective imitation, but in two previous studies they have also shown an eagerness to copy causally irrelevant actions. This so-called overimitation is prevalent in humans but is totally absent in great apes. Whereas in one of two previous studies dogs copied actions from an experimenter (Johnston, Holden, & Santos in Developmental Science, 20, e12460, 2017), in the other a reasonable number of the dogs copied the irrelevant actions from their human caregiver (Huber, Popovová, Riener, Salobir, & Cimarelli in Learning & Behavior, 46, 387-397, 2018). Dogs have not only been domesticated to live and work with us, but many companion dogs develop strong affiliative relationships with their caregiver, which are akin to the attachment bonds between human children and their mother. We therefore assumed that overimitation in dogs might be strongly motivated by social factors, such as affiliation or conformity. To test this hypothesis, we confronted dogs with the same demonstration of causally relevant and irrelevant actions as in the previous study (Huber et al. in Learning & Behavior, 46, 387-397, 2018), but this time with an unfamiliar experimenter instead of the caregiver as the demonstrator. The results strongly supported our hypothesis: Whereas half of the subjects in the previous study replicated the causally irrelevant action demonstrated by their caregiver, only very few did so when the actions were demonstrated by the experimenter. We conclude that the eagerness of dogs to learn from humans and to copy even unnecessary actions is strongly facilitated by their relationship with the particular human.

Assertive, trainable and older dogs are perceived as more dominant in multi-dog households

Social dominance is an important and widely used concept, however, different interpretations have led to ambiguity in the scientific literature and in popular science. Even though in ethology dominance is an attribute of dyadic encounters, and not a characteristic of the individual, 'dominance' has often been referred to as a personality trait in animals. Since few studies have specifically examined the link between personality traits and dominance status, we investigated this in dogs living in multi-dog households using a questionnaire, which required owners to specify whether the dog had a dominant or submissive status, and comprised items of both the features of the individual (i.e. personality traits) and previous social experience (interactions with group members and strangers). Four distinct personality factors emerged from 23 behavioural items by principal component analysis, labelled as assertiveness, trainability, intraspecific aggression and independence. Binomial logistic regression was used to examine how the demographic information of the dogs and the personality factors predicted the owner's estimate of the dog' status as dominant or submissive. The personality factor assertiveness accounted for 34% of the variance in dominance status, trainability 5% and dog age contributed 4%. Dogs perceived as dominant scored more highly on the factors assertiveness and trainability, which can help explain why 'dominance' has often been suggested to be a personality trait, rather than a dyad-specific social status according to different traditions in behavioural research. Similar to the 'social dominance' trait in humans, owner ascribed dominance showed a quadratic trajectory in cross-sectional mean change across the lifespan, increasing during adulthood and then maintaining high levels until old age. Overall, our study proposes a multifactorial background of dominance relationships in pet dogs, suggesting that not only previous experience of social interactions between individuals but also age and personality traits influence owner perceived dominance status in multi-dog households.

Would dogs copy irrelevant actions from their human caregiver?

Companion dogs learn easily from humans, including human behavior, human communication, and some aspects of the human-made environment. They benefit from having the opportunity to learn from humans and are able to spontaneously synchronize their behavior with that of their caregiver. Here, we tested whether pet dogs would show a special form of observational learning, one that has been considered uniquely human. Indeed, humans show overimitation, the faithful copying of causally irrelevant actions, but great apes do not. Because in humans this peculiar form of imitation is strongly motivated by social factors, such as affiliation or conformity, we hypothesized that domesticated and enculturated dogs are more likely than apes are to copy such actions, especially if shown by their affiliated caregiver. Indeed, half of the dogs replicated a causally irrelevant action that was demonstrated by their caregiver, and about the same number did this whether they saw only this action being demonstrated or being demonstrated before or after a causally relevant, functional action. The demonstration of a causally relevant action, one that is immediately followed by access to food, thus does not inhibit the copying of an action that is spatially separated and functionally opaque. Given that the copying frequency in this study was low overall, these results suggest evidence for overimitation in dogs, which might challenge the human uniqueness of this type of social learning.

Dominance in dogs as rated by owners corresponds to ethologically valid markers of dominance

Dominance is well defined in ethology, debated in psychology, and is often unclear among the dog owning public and in the press. However, to date, no study has examined how owners perceive dominance in dogs, and what different behaviours and personality types are used to describe dominant and subordinate individuals. A questionnaire study was launched to investigate the external validity of owner-derived estimates of dominance in dog dyads sharing the same household (N = 1,151). According to the owners, dogs rated as dominant (87%) have priority access to resources (resting place, food, and rewards), undertake certain tasks (defend and lead the group, bark more), display dominance (win fights, lick the other’s mouth less, and mark over the other’s urine), share certain personality traits (smarter, more aggressive and impulsive), and are older than their partner dog (all p < 0.0001). An age-related hypothesis has been suggested to explain dominance in dogs; but we found that dog age did not explain the occurrence of dominance related behaviours over the owners’ estimate of dominance status. Results suggest that owner-derived reports of dominance ranks of dogs living in multi-dog households correspond to ethologically valid behavioural markers of dominance. Size and physical condition were unrelated to the perceived dominance. Surprisingly, in mixed-sex dyads, females were more frequently rated as dominant than males, which might correspond to a higher proportion of neutered females in this subgroup. For future studies that wish to allocate dominance status using owner report, we offer a novel survey.

Investigating jealous behaviour in dogs

The function of jealous behaviour is to facilitate the maintenance of an important social relationship that is threatened by a third-party, a rival individual. Although jealous behaviour has an important function in gregarious species, it has been investigated almost exclusively in humans. Based on functional similarity between dog-owner and mother-infant attachments, we hypothesised that jealous behaviour can be evoked in dogs, similarly to children. In our study owners focused their attention solely on the test partner, while they ignored their dog. We deployed familiar and unfamiliar dogs as social test partners, and familiar and unfamiliar objects as non-social test partners; all subjects encountered all test partners. Dogs showed more jealous behaviour, i.e. owner-oriented behaviour and attempts to separate the owner and test partner in case of social compared to non-social test partners. Results suggest that jealous behaviour emerges in dogs, and it is functionally similar to that in children observed in similar situations. Alternative explanations like territoriality, dominance rank can be excluded.

Is a local sample internationally representative? Reproducibility of four cognitive tests in family dogs across testing sites and breeds

A fundamental precept of the scientific method is reproducibility of methods and results, and there is growing concern over the failure to reproduce significant results. Family dogs have become a favoured species in comparative cognition research, but they may be subject to cognitive differences arising from genetic (breeding lines) or cultural differences (e.g. preferred training methods). Such variation is of concern as it affects the validity and generalisability of experimental results. Despite its importance, this problem has not been specifically addressed to date. Therefore, we aimed to test the influence of three factors on reproducibility: testing site (proximal environment), breed and sex (phenotype). The same experimenter tested cognitive performance by more than 200 dogs in four experiments. Additionally, dogs' performance was tested in an obedience task administered by the owner. Breed of dog and testing site were found to influence the level of performance only mildly, and only in a means-end experiment and the obedience task. Our findings demonstrate that by applying the same test protocols on sufficiently large samples, the reported phenomena in these cognitive tests can be reproduced, but slight differences in performance levels can occur between different samples. Accordingly, we recommend the utilisation of well-described protocols supported by video examples of the whole experimental procedure. Findings should focus on the main outcome variables of the experiments, rather than speculating about the general importance of small or secondary performance outcomes which are more susceptible to random or local noise.

Dog rivalry impacts following behavior in a decision-making task involving food

Dogs learn a great deal from humans and other dogs. Previous studies of socially influenced learning between dogs have typically used a highly trained demonstrator dog who is unfamiliar to the observer. Because of this, it is unknown how dynamics between familiar dogs may influence their likelihood of learning from each other. In this study, we tested dogs living together in two-dog households on whether individual dogs' rivalry scores were associated with performance on a local enhancement task. Specifically, we wanted to know whether dog rivalry impacted whether an observer dog would approach a plate from which a demonstrator dog had eaten all available food, or whether the observer dog would approach the adjacent plate that still contained food. Dog rivalry scores were calculated using the Canine Behavioral Assessment and Research Questionnaire and indicated each dog's tendency to engage aggressively with the other household dog. Low-rivalry dogs were more likely to approach the empty plate than high-rivalry dogs when the observer dog was allowed to approach the plates immediately after the demonstrator had moved out of sight. This difference between low- and high-rivalry dogs disappeared, however, when observer dogs had to wait 5 s before approaching the plates. The same pattern was observed during a control condition when a human removed the food from a plate. Compared to low-rivalry dogs, high-rivalry dogs may pay less attention to other dogs due to a low tolerance for having other dogs in close proximity.

Do you see what I see? The difference between dog and human visual perception may affect the outcome of experiments

The visual sense of dogs is in many aspects different than that of humans. Unfortunately, authors do not explicitly take into consideration dog-human differences in visual perception when designing their experiments. With an image manipulation program we altered stationary images, according to the present knowledge about dog-vision. Besides the effect of dogs' dichromatic vision, the software shows the effect of the lower visual acuity and brightness discrimination, too. Fifty adult humans were tested with pictures showing a female experimenter pointing, gazing or glancing to the left or right side. Half of the pictures were shown after they were altered to a setting that approximated dog vision. Participants had difficulty to find out the direction of glancing when the pictures were in dog-vision mode. Glances in dog-vision setting were followed less correctly and with a slower response time than other cues. Our results are the first that show the visual performance of humans under circumstances that model how dogs' weaker vision would affect their responses in an ethological experiment. We urge researchers to take into consideration the differences between perceptual abilities of dogs and humans, by developing visual stimuli that fit more appropriately to dogs' visual capabilities.

Deceptive-like behaviour in dogs (Canis familiaris)

Deception, the use of false signals to modify the behaviour of the receiver, occurs in low frequencies even in stable signalling systems. For example, it can be advantageous for subordinate individuals to deceive in competitive situations. We investigated in a three-way choice task whether dogs are able to mislead a human competitor, i.e. if they are capable of tactical deception. During training, dogs experienced the role of their owner, as always being cooperative, and two unfamiliar humans, one acting 'cooperatively' by giving food and the other being 'competitive' and keeping the food for themselves. During the test, the dog had the options to lead one of these partners to one of the three potential food locations: one contained a favoured food item, the other a non-preferred food item and the third remained empty. After having led one of the partners, the dog always had the possibility of leading its cooperative owner to one of the food locations. Therefore, a dog would have a direct benefit from misleading the competitive partner since it would then get another chance to receive the preferred food from the owner. On the first test day, the dogs led the cooperative partner to the preferred food box more often than expected by chance and more often than the competitive partner. On the second day, they even led the competitive partner less often to the preferred food than expected by chance and more often to the empty box than the cooperative partner. These results show that dogs distinguished between the cooperative and the competitive partner, and indicate the flexibility of dogs to adjust their behaviour and that they are able to use tactical deception.

Exploring the evolutionary origins of overimitation: a comparison across domesticated and non-domesticated canids

When learning from others, human children tend to faithfully copy - or 'overimitate' - the actions of a demonstrator, even when these actions are irrelevant for solving the task at hand. We investigate whether domesticated dogs (Canis familiaris) and dingoes (Canis dingo) share this tendency to overimitate in three experiments. In Experiment 1, dogs and dingoes had the opportunity to solve a puzzle after watching an ostensive demonstrator who used both a relevant action and an irrelevant action. We find clear evidence against overimitation in both species. In contrast to human children (Horner & Whiten, 2005), dogs and dingoes used the irrelevant action less often across trials, suggesting that both species were filtering out the irrelevant action as they gained experience with the puzzle (like chimpanzees; Horner & Whiten, 2005). Experiments 2 and 3 provide further evidence against overimitation, demonstrating that both species' behavior is better characterized by individual exploration than overimitation. Given that both species, particularly dogs, show human-like social learning in other contexts, these findings provide additional evidence that overimitation may be a unique aspect of human social learning. A video abstract of this article can be viewed at: https://youtu.be/g2mRniJZ7aU.

Deferred imitation and declarative memory in domestic dogs

This study demonstrates for the first time deferred imitation of novel actions in dogs (Canis familiaris) with retention intervals of 1.5 min and memory of familiar actions with intervals ranging from 0.40 to 10 min. Eight dogs were trained using the 'Do as I do' method to match their own behaviour to actions displayed by a human demonstrator. They were then trained to wait for a short interval to elapse before they were allowed to show the previously demonstrated action. The dogs were then tested for memory of the demonstrated behaviour in various conditions, also with the so-called two-action procedure and in a control condition without demonstration. Dogs were typically able to reproduce familiar actions after intervals as long as 10 min, even if distracted by different activities during the retention interval and were able to match their behaviour to the demonstration of a novel action after a delay of 1 min. In the two-action procedure, dogs were typically able to imitate the novel demonstrated behaviour after retention intervals of 1.5 min. The ability to encode and recall an action after a delay implies that facilitative processes cannot exhaustively explain the observed behavioural similarity and that dogs' imitative abilities are rather based on an enduring mental representation of the demonstration. Furthermore, the ability to imitate a novel action after a delay without previous practice suggests presence of declarative memory in dogs.