Ownership is a relationship between an agent and items regarded as the agent’s property. Ownership typically entails that the agent has rights over the property that are not shared by others. For example, the owner of a shed is normally entitled to store items in the shed and to decide whether others are permitted to enter it. Ownership may also entail obligations and duties in relation to the property. If the shed collapses, damaging a neighbor’s yard, the owner of the shed may be liable. Ownership affects actions, thoughts, and feelings. It underlies choices of which objects to use and is at the center of buying, selling, borrowing, and lending. This is true for people everywhere, as ownership is thought to be a human universal, and some rules of ownership may be shared across all societies. Nonetheless, the origins and nature of ownership are widely disputed, and the different positions make it relevant to questions central in the cognitive sciences, such as the debate between conceptual empiricism and nativism.

History

Ownership has been discussed in the oldest known legal texts, including the Codes of Hammurabi and of Eshnunna—both from ancient Iraq over 3,700 years ago—which set out alternative views about when owners are responsible for harms caused by their property. Early philosophers, including Plato and Aristotle, discussed justifications for the idea of ownership and debated the merits of collective versus private ownership (Waldron, 2023). In the 17th and 18th centuries, philosophers likewise debated the basis and justification for owning things, with some arguing that ownership is a cultural and legal invention (e.g., Hobbes and Hume) and others seeing it as having natural origins (e.g., Locke), a debate which continues today.

Ownership is investigated by scholars from numerous fields. Philosophers and legal theorists offer accounts of what ownership is and about the nature of ownership rules (e.g., Merrill & Smith, 2020). Anthropologists have documented ownership practices across cultures (Brown, 1991; Singh, 2022; Turner, 2017); this topic is also investigated using experimental methods (e.g., Białek et al., 2024). Linguists grapple with how ownership is expressed in different languages and distinguished from other related states, like possession (e.g., Goddard & Wierzbicka, 2016). Psychologists conduct experiments on aspects of ownership, including people’s valuations of objects, subjective feelings of ownership, and their judgments about ownership disputes (e.g., Morewedge & Giblin, 2015; Nancekivell et al., 2019; Pierce et al., 2003). Psychological work also investigates how ownership emerges and develops in toddlers and young children (Pesowski et al., 2022) and which features of ownership are shared by other species (Tibble & Carvalho, 2018).

Core concepts

Researchers sometimes distinguish between legal and psychological ownership. Legal ownership is socially recognized. For example, when you buy a book, people normally recognize that it belongs to you and that you have rights over the book—you are entitled to read it, whereas others would require permission to do this. By contrast, psychological ownership is the feeling that something is yours and can arise for things that are not socially recognized as your property. For instance, if you often occupy the same table at your local library, you may come to feel as though it is your spot, even though you are not recognized as owning it. As a consequence, if you insisted that someone else has to vacate the spot so that you can use it, other people would be unlikely to take your side.

Ownership rights are the specific privileges that owners have over their property. Owners are often posited to have the right of use, which entitles them to use their property; the right of exclusion, which entitles owners to decide whether others can use their property; and the right of transfer, which entitles owners to give or sell property to others.

The endowment effect is the tendency to place greater value on a thing if it belongs to you compared with if it does not (Kahneman et al., 1991). For instance, a person endowed with a coffee mug will generally demand a higher price for selling it compared with how much the person would have been willing to pay to buy the mug. The mere ownership effect, similarly, is the tendency to prefer one’s own property over non-owned things (Beggan, 1992).

Questions, controversies, and new developments

What are ownership rights, and how are they structured?

Some accounts posit that ownership implies specific rights, such as the aforementioned rights of use, exclusion, and transfer property (e.g., Snare, 1972). Other accounts hold that ownership comes down to just one right or principle—some have claimed that the right of exclusion is most central to ownership (e.g., Cohen, 1954 and Merrill, 1998), whereas another account holds that ownership is about having the exclusive authority to decide how a thing is used (Katz, 2008). Meanwhile bundle of rights accounts posit that although owners can be assigned various rights, no particular right or combination of rights is privileged or required for ownership (Merrill & Smith, 2020; Waldron, 2023).

Where do notions of ownership come from? What is their basis?

Ownership could be a legal or social convention—a set of norms around objects that cultures create and that are then passed down and modified across generations. On this view, to the extent that disparate cultures and societies have similar ownership rules, this is because different peoples have hit on similar norms for governing how to allocate control over valued resources.

Conversely, ownership could have a natural and noncultural basis. People could be endowed with a naive theory of ownership, which sets out principles specific to governing their relations with resources (e.g., Nancekivell et al., 2019). On this view, the psychology of ownership could descend from territoriality in animals (e.g., Stake, 2004) or could stem from people’s conceptions of self and their sense of bodily rights—beliefs that owners are entitled to control property could be extensions of the belief that people are entitled to control their bodies (e.g., Humphrey, 1992).

Ownership could also result from the interplay of culture and natural forces. Thus, ownership rules might be culturally created but in ways shaped and constrained by feelings of ownership. Relatedly, one recent account posits that ownership intuitions arise from evolved cognitive systems specialized for functions not specific to ownership and that these intuitions apply both to items seen as property and to those not seen as truly owned (e.g., a temporarily occupied train seat; Boyer, 2023).

Broader connections

Competing accounts of the nature of ownership imply differing connections to other fields in the cognitive sciences. Territoriality in animals may be more relevant, for instance, if many aspects of the psychology of ownership reflect specific cognitive adaptations than if ownership is a cultural invention. At the same time, the contours of the debate about the nature of ownership are not specific to ownership. Indeed, this debate can be seen as a case study relevant for broader debates about the origins of social norms, concepts, and intuitive theories [see Normativity; Concepts; Intuitive Theories].

Besides functioning to allocate control over valued physical resources, the psychology of ownership extends to other things. We can view ideas as intellectual property and may even think of countries and cultural practices as belonging to groups (e.g., Shaw et al., 2012; Verkuyten & Martinovic, 2017). Much remains to be learned about these aspects of ownership and how they connect to broader social issues (e.g., plagiarism, cultural theft, nationalism).

Acknowledgments

This work was supported by an Insight Grant from the Social Sciences and Humanities Research Council of Canada.

Further reading

• Boyer, P. (2023). Ownership psychology as a cognitive adaptation: A minimalist model. Behavioral and Brain Sciences, 46, e323. https://doi.org/10.1017/S0140525X22002527

• Heller, M. A., & Salzman, J. (2022). Mine! How the hidden rules of ownership control our lives. Doubleday.

• Morewedge, C. K. (2021). Psychological ownership: Implicit and explicit. Current Opinion in Psychology, 39, 125–132. https://doi.org/10.1016/j.copsyc.2020.10.003

• Nancekivell, S. E., Friedman, O., & Gelman, S. A. (2019). Ownership matters: People possess a naïve theory of ownership. Trends in Cognitive Sciences, 23, 102-113. https://doi.org/10.1016/j.tics.2018.11.008