Modeling ownership in non-human species: an argument for the domestic dog

Abstract

The concept of ownership has been extensively examined within the context of human psychology, with a strong focus on how individuals represent relationships between people and objects (e.g., Boyer, 2023;Nancekivell et al., 2019). Comparative work has been relatively limited, with a small number of studies exploring these questions in non-human animals, primarily non-human primates (e.g., Kanngiesser, 2023). Currently, prevailing frameworks conclude that, while animals may exhibit an understanding and respect for possession, they do not demonstrate the more complex ownership concepts seen in humans.We argue that the domestic dog (Canis familiaris) represents a particularly valuable and under-explored model for investigating ownership-like concepts across species. We first review existing evidence for ownership-related behaviour in non-human animals, then outline why dogs are especially well suited to this line of inquiry. Finally, we discuss how expanding ownership research to include dogs could refine theoretical ownership frameworks and generate practical applications for animal welfare and training.A critical step in investigating ownership research beyond humans has been the development of operational, species-neutral definitions. For example, Tibble & Carvalho (2018) integrated fields that explore ownership-specifically evolutionary game theory, ethology, developmental psychology, and comparative cognition-to distinguish between possession and property. Possession refers to situations where an individual maintains physical control over an object, and others respect this control as a claim to that object (see also Brosnan, 2011). In contrast, property (sometimes construed as true ownership) involves an individual maintaining exclusive access to an object even in the absence of direct physical control, which likely requires more complex social cognitive processing. Under these definitions, there is broad agreement that many animal species demonstrate behaviours consistent with possession. Non-human primates avoid taking objects that are under another's physical control (e.g., Sigg & Falett, 1985;Kummer & Cords, 1991), even when the individual in control is lower in dominance rank. Additionally, several primate species show evidence of the endowment effect; they value objects more once they are in their possession (Drayton et al., 2013;Flemming et al., 2012;Kanngiesser et al., 2011; but see Santos & Rosati, 2015). Similar respect for possession has been shown in corvids (Heinrich, 1999), indicating this is not a primate-specific phenomenon.Possession can be understood as an evolutionarily stable strategy because simple behavioral rules like 'respect those currently in control of a resource' minimize costly conflicts and thus provide consistent fitness benefits across individuals (e.g., Stake, 2004;Tibble & Carvalho, 2018). When widely adopted, this strategy becomes stable since individuals who deviate (e.g., by always challenging possession) incur higher costs and are less likely to succeed, reinforcing possession-based behavior in the population.Yet, there is currently no clear empirical evidence that non-human animals demonstrate property under this distinction. Some researchers have thus concluded that humans are unique, demonstrating ownership behaviours and maintaining a social institution of ownership-a system of shared norms governing resource access and transfer (e.g., Brosnan, 2011;Kanngiesser et al., 2020). Importantly, the lack of evidence for property in animals may reflect limitations in the species and contexts studied, rather than a true absence of ownership-related cognition. If ownership depends on norm-governed interactions, then species that regularly participate in complex, cooperative social systems-including interactions with humans-may be especially informative.Through a long process of domestication, dogs have come to live in close association with humans, relying on us for resources, social structure, and environmental organization. As a result, dogs routinely operate within social systems that are shaped by human-imposed ownership norms. Below, we describe how evolutionary and domestication factors, combined with social cognitive processes and exposure to human ownership norms, could plausibly lead to not only conceptions of possession, but also property.The Canine Ancestry Hypothesis (Hare et al., 2002) posits that dogs' ability to engage in interspecific communication has evolutionary roots shared with wolves. Wolves themselves live in highly cooperative family groups, where resource distribution and pup-rearing involve coordinated behaviour. Research suggests that wolves respect possession of territory and food items. For example, individuals that acquire small prey are typically allowed to retain it, regardless of dominance status (Zimen, 1970, as cited in Range & Marshall-Pescini, 2022).Such behaviours imply that foundational components of ownership, such as respect for possession, may have existed prior to domestication (e.g., Stake, 2004). Domestication could then have elaborated these tendencies within human-controlled environments. Historically, dogs likely played roles in guarding human camps and resources (Chambers et al., 2020). Features such as attention-grabbing barks (Jégh-Czinege et al., 2020;Pongrácz et al., 2016) and high alertness during rest (Koreckaas & Kotrschal, 2019) may have been advantageous for signaling potential threats to property. If dogs were selected to assist in defense of solely their guardian's resources, it is plausible that sensitivity to distinctions such as "mine," "yours," and "ours" would confer adaptive benefits. At a minimum, dogs would benefit from distinguishing relevant versus irrelevant threats when responding to potential violations of access.Dogs possess sophisticated social-cognitive abilities, particularly in their interactions with humans (e.g., Albuquerque et al., 2022;Horschler et al., 2022;Miklósi et al., 2000;Virányi et al., 2004). Dogs outperform primates in certain tasks involving human communicative cues (Hare & Tomasello, 2005), likely due to selective pressures during domestication. Importantly, these abilities emerge early in development: dog puppies show greater responsiveness to human gestures than hand-reared wolf puppies, and the understanding of human gestures increases with age and experience (Salomons et al., 2021). This suggests that domestication has produced species-typical adaptations for engaging with human social systems that are elaborated upon with experience. The relevance to ownership research lies in the possibility that dogs may not only track human intentions and signals but also internalize aspects of human-defined social rules regarding objects. Supporting this, a recent survey indicated that North American guardians often attribute ownership-like states to their dogs (e.g., endorsing statements regarding their dog owning certain toys and items: Sundby, 2025), potentially shaping dogs' experiences and expectations.There is reason to think that dogs may have components of what is termed "norm psychology" in that they do not solely respond to immediate reinforcement histories in all situations, but may be representing and complying with more general, socially defined expectations. Indeed, emerging work suggests that social norms may not be uniquely human. Westra and colleagues (2024), for example, have proposed that norm-like processes may also occur in highly social species such as canids, as seen in the regulation of behavior during play fighting (e.g., signals such as play bows, modifying behavior based on the size and age of partner). Further, empirical evidence supports that dogs are capable of flexibly learning social rules; dogs can follow instructions that conflict with their own knowledge (e.g., searching for an object in an incorrect location: Topál et al., 2005).Unlike many other species studied in ownership research, dogs are embedded in heterospecific social environments where rules are often explicitly taught and enforced, including those governing access to food, toys, and spaces within the household. Thus, dogs' capacity for norm psychology, coupled with exposure to human ownership norms, may lead to the development of ownership concepts like property. Yet, variation would be expected. Guardian beliefs regarding object ownership (e.g., whether a dog owns its toy) likely vary, and thus local household norms and accompanying behavior would vary as well.Further, multi-dog households would provide an opportunity to examine whether ownership-like norms are maintained between dogs, particularly with respect to toys. Recent laboratory research suggests that toy possession is influenced by dominance relationships (Vékony & Pongrácz, 2024). However, dominance and ownership need not be competing explanations; in humans, ownership norms can also be constrained by power relationships.Determining whether dogs respect another dog's access to an object because of the individual's rank, prior possession, ownership, guardian intervention, or some combination of these factors remains an open question. Multi-dog households may therefore provide a useful naturalistic context for disentangling these influences.We have suggested that dogs may be a particularly relevant model for the question of whether animals are limited to possession behaviours, or if they have some recognition of property. The study of dogs would serve to either confirm conclusions that animals are limited to possession or force elaboration of current theories to accommodate animals showing some instances of property.Additionally, findings with dogs would inform current theories regarding the cognitive mechanisms supporting ownership representations. For example, Nancekivell et al. (2019) propose that human ownership reasoning is best characterized as a naïve theory-a domainspecific system of knowledge that supports causal explanation and prediction. Naïve theories are shaped by early-emerging cognitive structure and experience, including cultural norms. If dogs participate in norm-governed interactions with humans, they may acquire components of an ownership-like system through repeated engagement with human rules regarding resource access. We suspect that dogs do not share a full human concept of ownership. Instead, dogs may represent a partial or differently structured naïve theory, allowing the examination of which components of ownership cognition are dependent on human-specific institutions and which may arise more broadly across species.Currently, we see two complementary experimental and observational approaches to explore the ideas presented in this opinion piece. First, dogs demonstrating behavioural rulefollowing, such as only taking certain items, even in the absence of the owner and in the absence of physical control, or dogs showing a sensitivity to violations of ownership rules (e.g., returning an object to the first person who had it), would be consistent with compliance and encoding of ownership-related norms. Second, experimental tasks could be designed to examine some of the "cognitive hallmarks" of ownership representations found in humans and children, such as attentional biases toward and increased valuation of owned objects (e.g., Constable et al., 2014;Cunningham et al., 2008;Gelman et al., 2012;Kritikos et al., 2020;van den Bos et al., 2010).At this point, the suggestions we are making are limited to dogs who live with repeated interaction with specific humans and objects; we believe it is through dog-human interaction that the dog's representations of ownership may be developed and maintained. Free-ranging (street/feral) domestic dogs would provide an interesting comparison, as these dogs would not have similar levels of exposure and opportunity to learn social norms regarding object ownership. Yet, free-ranging dogs do have similar general social cognitive abilities to companion and working/service dogs, such as sensitivity to human communication, gaze, and emotion (e.g., Bhattacharjee et al., 2018;Bhattacharjee et al., 2020).Lastly, we note that research into dogs' ownership concepts will have training and welfare applications. For example, persistence towards toys during difficult tasks, focus on toys, and object location memory are sometimes used to evaluate dogs' eligibility to progress as working and service dogs, including best fit for particular jobs (Bray et al., 2017;Lazarowski et al., 2019;MacLean & Hare, 2018). Dogs' history with these toys has not been systematically manipulated in these tasks; yet, from research with humans, we know that both adults and children show different cognitive processing of owned objects compared to familiar objects (e.g., attention and memory, Blake & Harris, 2011;Cunningham et al., 2008;Gelman et al., 2012). Thus, we do not know whether ownership and its associated cognitive biases would affect performance and, ultimately, appropriate job placement and welfare.Domestic dogs may provide a uniquely informative species for exploring ownership beyond humans. Whereas existing research suggests that many animals demonstrate behaviours consistent with possession, ownership has largely been considered uniquely human due to its association with social institutions. We argue that this conclusion may be premature. Dogs' close integration into human social systems, combined with their advanced social cognition and evolutionary history, positions them as an informative model for understanding whether ownership-like concepts can emerge outside of strictly human contexts. By expanding ownership research to include dogs, we can refine theoretical accounts of ownership, distinguish between cognitive and institutional components, and potentially identify shared principles underlying resource regulation across species. At the same time, this work holds practical value for improving training practices and promoting animal welfare.