The nonobvious basis of ownership: preschool children trace the history and value of owned objects

Mine for life: Charting ownership effects in memory from adolescence to old age

This study investigates the self-reference effect (SRE) with an ownership memory task across several age groups, providing the first age exploration of implicit ownership memory biases from adolescence to older adulthood (N = 159). Using a well-established ownership task, participants were required to sort images of grocery items as belonging to themselves or to a fictitious unnamed Other. After sorting and a brief distractor task, participants completed a surprise one-step source memory test. Overall, there was a robust SRE, with greater source memory accuracy for self-owned items. The SRE attenuated with age, such that the magnitude of difference between self and other memory diminished into older adulthood. Importantly, these findings were not due to a deterioration of memory for self-owned items, but rather an increase in memory performance for other-owned items. Linear mixed effects analyses showed self-biases in reaction times, such that self-owned items were identified more rapidly compared with other owned items. Again, age interacted with this effect showing that the responses of older adults were slowed, especially for other-owned items. Several theoretical implications were drawn from these findings, but we suggest that older adults may not experience ownership-related biases to the same degree as younger adults. Consequently, SREs through the lens of mere ownership may attenuate with age.

People Have Systematically Different Ownership Intuitions in Seemingly Simple Cases

Our understanding of ownership influences how we interact with objects and with each other. Here, we studied people's intuitions about ownership transfer using a set of simple, parametrically varied events. We found that people (N = 120 U.S. adults) had similar intuitions about ownership for some events but sharply opposing intuitions for others (Experiment 1). People (N = 120 U.S. adults) were unaware of these conflicts and overestimated ownership consensus (Experiment 2). Moreover, differences in people's ownership intuitions predicted their intuitions about the acceptability of using, altering, controlling, and destroying the owned object (N = 130 U.S. adults; Experiment 3), even when ownership was not explicitly mentioned (N = 130 U.S. adults; Experiment 4). Subject-level analyses suggest that these disagreements reflect at least two underlying intuitive theories, one in which intentions are central to ownership and another in which physical possession is prioritized.

Ownership as an extension of self: An alternative to a minimalist model

Our commentary challenges Boyer's model by arguing that the extended-self is a more likely basis for ownership psychology. We outline how self-based principles of investment and control might structure thinking about ownership and related rights. We end by expanding the extended-self account to include welfare, as a way of understanding the contexts under which ownership is upheld or violated.

Development, history, and a minimalist model of ownership psychology

Boyer's minimalist model is a compelling account of ownership psychology that is more efficient than previous models. However, it is unclear whether the two simple systems that make up this model - acquisitiveness and cooperation - are sufficient to both explain the nuanced development of ownership concepts and to account for the prominent influence that history has on ownership psychology.

Ownership psychology, its antecedents and consequences

Commentators discussed the coherence and validity of a minimalist approach to ownership intuitions, in ways that make it possible to clarify the model, re-evaluate its cognitive underpinnings, and sketch some of its implications. This response summarizes the model; addresses issues concerning the need for a special technical lexicon when describing cognitive semantics; the psychology involved in contexts of competitive acquisition and their consequences for possession and use of rival resources; the role of cooperative expectations in creating mutually beneficial allocation of resources; the consequences of ownership psychology for social interaction and the production of social norms of property; and the relations between psychological processes and legal institutions in the domain, before proposing some final thoughts.

Collective psychological ownership as a new angle for understanding group dynamics

Even without legal ownership, groups can experience objects, places, and ideas as belonging to them ('ours'). This state of mind-collective psychological ownership-is understudied in social psychology, yet it is central to many intergroup conflicts and stewardship behaviour. We discuss our research on the psychological processes and social-psychological implications of collective psychological ownership. We studied territorial ownership, in different parts of the world and at different geographical levels, offering not only a cross-national but also conceptual replication of the processes. Our findings show that collective psychological ownership is inferred based on primo-occupancy, investment, and formation. Further, we demonstrate that collective psychological ownership can have positive intragroup and negative intergroup outcomes, which are guided by perceived group responsibility and exclusive determination right. We then discuss ownership threat (losing what is 'ours'), and we consider the role of group identification in ownership-related processes. We conclude by providing directions for future research.

Preliminary evidence for progressions in ownership reasoning over the preschool period

Defining developmental progressions can be an important step in identifying developmental precursors and mechanisms of change, within and across areas of reasoning. In one exploratory study, we examine whether the development of children's thinking about ownership follows a systematic progression wherein some components emerge reliably before others. We examine this issue in a sample of 72 children: 40 older 2-year-olds, Mage = 2.78 (.14); R = 2.50-3.00, and 32 older 4-year-olds, Mage = 4.77 (.16); R = 4.50-5.00, living in Michigan in the United States. We use a battery of four established ownership tasks that tested different aspects of children's ownership thinking. A Guttman test revealed a reliable sequence that explained 81.9% of children's performance. Namely, we discovered that identifying familiar owned objects emerged first, control of permission as a cue to ownership second, understanding ownership transfers third, and the tracking of sets of identical objects last. This ordering suggests two foundational ownership abilities on which more complex reasoning may be built: the ability to include information about familiar owners in children's mental models of objects and recognizing that control is central to ownership. The observed progression is an important first step toward developing a formal ownership scale. This study paves the way for mapping the conceptual and information-processing demands (e.g., executive functioning, memory) that likely underlie change in ownership thinking across childhood. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Testing the bounds of compassion in young children

Extensive research shows that, under the right circumstances, children are highly prosocial. Extending an already published paradigm, we aimed here to determine what factors might facilitate and inhibit compassionate behaviour. Across five experiments (N = 285), we provide new insight into the bounds of 4- to 5-year-old children's compassionate behaviour. In the first three experiments, we varied cost of compassion by changing the reward (Study 1), using explicit instructions (Study 2) and ownership (Study 3). In the final two experiments, we varied the target of the compassionate behaviour, examining adults compared with puppet targets (Study 4), and whether the target was an in-group member (Study 5). We found strong evidence that cost reduces compassionate responding. By contrast, the recipient of compassion did not appear to influence responding: children were equally likely to help a human adult and a puppet, and an in-group member and neutral agent. These findings demonstrate that for young children, personal cost appears to be a greater inhibitor to compassionate responding than who compassion is directed toward.

Exploring the Influence of Object Similarity and Desirability on Children's Ownership Identification and Preferences in Autism and Typical Development

This study investigated how ownership identification accuracy and object preferences in children with autism spectrum disorder (ASD) are influenced by visual distinctiveness and relative desirability. Unlike typically developing (TD) children matched on receptive language (M age equivalents: 58.8-59.9 months), children with ASD had difficulty identifying another person's property when object discriminability was low and identifying their own relatively undesirable objects. Children with ASD identified novel objects designated to them with no greater accuracy than objects designated to others, and associating objects with the self did not bias their preferences. We propose that, due to differences in development of the psychological self, ownership does not increase the attentional or preferential salience of objects for children with ASD.

Children's Understanding of Proper Names and Descriptions

This research addressed the question of whether children understand proper names differently from descriptions. We examined how children extend these two types of expressions from an initial object (a truck) owned by the experimenter to two identical objects created by transforming the initial object, both owned by the experimenter. Adults and 5/6-year-olds extended a name ("Tommy") to only one post-transformation object, but extended a description ("my truck") to both objects. Adults and 7-year-olds (but not 5/6-year-olds) also extended a description modeled as a name ("called My Truck") to only one object. Like adults, children understand that proper names identify unique individuals, but that descriptions identify properties.

How the Custom Suppresses the Endowment Effect: Exchange Paradigm in Kanak Country

In this paper, Knetsch's exchange paradigm is analyzed from the perspective of pragmatics and social norms. In this paradigm the participant, at the beginning of the experiment, receives an object from the experimenter and at the end, the same experimenter offers to exchange the received object for an equivalent object. The observed refusal to exchange is called the endowment effect. We argue that this effect comes from an implicature made by the participant about the experimenter's own expectations. The participant perceives the received item as a gift, or as a present, from the experimenter that cannot be exchanged as stipulated by the social norms of western politeness common to both the experimenter and the participant. This implicature, however, should not be produced by participants from Kanak culture for whom the perceived gift of a good will be interpreted as a first act of exchange based on gift and counter-gift. This exchange is a natural, frequent, balanced, and indispensable act for all Kanak social bonds whether private or public. Kanak people also know the French social norms that they apply in their interactions with French people living in New Caledonia. In our experiment, we show that when the exchange paradigm takes place in a French context, with a French experimenter and in French, the Kanak participant is subject to the endowment effect in the same way as a French participant. On the other hand, when the paradigm is carried out in a Kanak context, with a Kanak experimenter and in the vernacular language, or in a Kanak context that approaches the ceremonial of the custom, the endowment effect is no longer observed. The same number of Kanak participants accept or refuse to exchange the endowed item. These results, in addition to providing a new explanation for the endowment effect, highlight the great flexibility of decisions according to social-cultural context.

Does Autism Affect Children's Identification of Ownership and Defence of Ownership Rights?

This study investigated how autism spectrum disorder (ASD) impacts children's ability to identify ownership from linguistic cues (proper nouns vs. possessive pronouns) and their awareness of ownership rights. In comparison to typically developing (TD) children matched on receptive language (M age equivalents: 53-56 months), children with ASD were less accurate at tracking owner-object relationships based on possessive pronouns and were less accurate at identifying the property of third parties. We also found that children with ASD were less likely to defend their own and others' ownership rights. We hypothesise that these results may be attributed to differences in representing the self and propose that ASD may be characterised by reduced concern for ownership and associated concepts.

Children's understanding of economic demand: A dissociation between inference and choice

Adults infer that resources that become scarce over time are in higher demand, and use this "demand inference" to guide their own economic decisions. However, it is unclear when children begin to understand and use economic demand. In six experiments, we investigated the development of demand inference and demand-based economic decisions in 4- to 10-year-old children and adults in the United States. In Experiments 1-5, we showed children two boxes with the same number of compartments but containing different numbers of face-down stickers and varied the information provided about how those differences arose (e.g. that other children had taken the stickers). In separate experiments, we asked children to buy or trade to get a sticker for themselves or to predict what other children would do. We also asked them which set of stickers they thought the other children had preferred to assess their ability to make a demand inference separately from their own choice. Across experiments, children were able to make a demand inference about children's past preferences by 6 years of age. However, children did not use this demand information when making choices for themselves or when predicting what another child would select in the future. In Experiment 6, we adapted the task for adults and found that adult participants inferred that the set containing fewer resources was in higher demand, and selected the higher demand resource for themselves at rates significantly above chance. The overall pattern of results suggests a dissociation between economic inference and economic decisions during early-to-middle childhood. We discuss implications for our understanding of the development of economic reasoning.

A Dollar Is a Dollar Is a Dollar, or Is It? Insights From Children's Reasoning About "Dirty Money"

Money can take many forms-a coin or a bill, a payment for an automobile or a prize for an award, a piece from the 1989 series or the 2019 series, and so on-but despite this, money is designed to represent an amount and only that. Thus, a dollar is a dollar, in the sense that money is fungible. But when adults ordinarily think about money, they think about it in terms of its source, and in particular, its moral source (e.g., dirty money). Here we investigate the development of the belief that money carries traces of its moral history. We study children ages 5-6 and 8-9, who are sensitive to both object history and morality, and thus possess the component pieces needed to think that a dollar may not be like any other. Across three principal studies (and three additional studies in Appendix S1; N = 327; 219 five- and six-year-olds; 108 eight- and nine-year-olds), we find that children are less likely to want money with negative moral history, a pattern that was stronger and more consistent among 8- and 9-year-olds than 5- and 6-year-olds. These findings highlight pressing directions for future research that could help shed light on the mechanisms that contribute to the belief that money carries traces of its moral history.

Control it and it is yours: Children's reasoning about the ownership of living things

One of the hallmarks of ownership is the right to control one's property. Living beings thus pose an interesting puzzle for ownership, since they have some capacity to decide what happens to themselves-they can direct their own motion, pursue their own goals, and make their own decisions. Recent work has shown that adults consider this autonomy to be the key factor in determining whether a human (or human-like) being can be owned. However, little is known about how children reason about the ownership of living beings. Across three experiments we show that children (ages 4-7) use principles of control and autonomy to reason about the ownership of familiar and novel animals. At all ages tested, children were more likely to say that a typically wild animal (e.g., a bear) was owned if a homeowner had controlled its movements by putting it in a cage, rather than simply standing near it in their yard (Experiment 1). Children also used this cue of control to predict whether novel animals were owned (Experiment 2)-and for these unfamiliar animals, the effect of control was even larger. Finally, Experiment 3 found that children's judgments were not specifically driven by the use of a cage to control the animal, but also extended to animals that inherently had the ability to escape (e.g., fly or jump). These autonomous animals were judged as non-owned, while those that could not escape were judged as owned. The use of these principles was evident at all ages, but became stronger with age, particularly when considering novel animals. These are the first studies, to our knowledge, to investigate the development of reasoning about the ownership of animals, and they suggest that, like adults, children consider autonomy an essential factor in the ownership of living things.

Beliefs About the Persistence of History in Objects and Spaces in the United States and India

Scattered evidence in the literature suggests that people may believe that non-visible traces of past events (e.g., origins, emotions, and qualities of the owner) persist over time in objects and spaces, even after the original source has been removed. To date, however, there has been no unified treatment to determine the scope and cultural consistency of this expectation. This study had four primary goals: (a) to assess how broadly participants display persistence-of-history beliefs, (b) to explore individual differences in these beliefs, (c) to examine the explanatory frameworks for these beliefs, and (d) to determine whether these beliefs were endorsed across two cultural settings. Adults in both United States ( N = 195) and India ( N = 173) evaluated a broad range of situations involving possible persistence of history. In both countries, three patterns emerged: (a) A broad range of persistence-of-history scenarios were judged to be possible, falling into two underlying thematic clusters (supernatural vs. non-supernatural); (b) paranormal beliefs predicted endorsement of items in both thematic clusters; and yet (c) most scenarios were explained using natural explanatory frameworks. Together, these results demonstrate broad endorsement of the persistence of history—across cultures, situations, and individuals—as well as substantial individual variation.

Self-bias effect: movement initiation to self-owned property is speeded for both approach and avoidance actions

Recall of, and physical interaction with, self-owned items is privileged over items owned by other people (Constable et al. in Cognition 119(3):430-437, 2011; Cunningham et al. in Conscious Cognit 17(1):312-318, 2008). Here, we investigate approach (towards the item), compared with avoidance (away from the item) movements to images of self- and experimenter-owned items. We asked if initiation time and movement duration of button-press approach responses to self-owned items are associated with a systematic self-bias (overall faster responses), compared with avoidance movements, similar to findings of paradigms investigating affective evaluation of (unowned) items. Participants were gifted mugs to use, and after a few days they completed an approach-avoidance task (Chen and Bargh in Pers Soc Psychol Bull 25(2):215-224, 1999; Seibt et al. in J Exp Soc Psychol 44:713-720, 2008; Truong et al. in J Exp Psychol Hum Percept Perform 42(3), 375-385, 2016) to images of their own or the experimenter's mug, using either congruent or incongruent movement direction mappings. There was a self-bias effect for initiation time to the self-owned mug, for both congruent and incongruent mappings, and for movement duration in the congruent mapping. The effect was abolished in Experiment 2 when participants responded based on a shape on the handle rather than mug ownership. We speculate that ownership status requires conscious processing to modulate responses. Moreover, ownership status judgements and affective evaluation may employ different mechanisms.

Exploring the influence of ownership history on object valuation in typical development and autism

Items with special histories (e.g. celebrity owners) or qualities (e.g. limited editions) are more valuable than similar "inauthentic" items. Typically developing (TD) children privilege authenticity and are particularly influenced by who objects belong to. Here, we explore why children and adults over-value items with special ownership histories and examine how autism spectrum disorder (ASD) affects object valuation. In Studies 1 and 2, TD children perceived items belonging to famous owners (with "good" or "bad" reputations) to be more valuable than similar items belonging to non-famous owners. However, they ascribed significantly higher values to items belonging to famous heroes than infamous villains when compared. Children with ASD did not over-value objects with special ownership histories, but their valuations were moderated by qualities unrelated to ownership (e.g. rarity). In Study 3, adults with ASD assigned high values to authentic items with special ownership histories but were more likely to keep inauthentic objects than neurotypical adults. Our findings show that association with a famous owner is sufficient to increase an item's value for TD children and adults (with and without ASD). The degree of added value may be determined by the famous owner's character for TD children, but not adults. By contrast, children with ASD value objects via a different strategy that prioritizes material qualities over ownership history. However, the awareness of authenticity displayed by adults with ASD suggests that the emergence of ownership history as an important influence on object evaluation may be developmentally delayed in ASD, rather than completely absent.

To have and to hold: embodied ownership is established in early childhood

We investigated whether embodied ownership is evident in early childhood. To do so, we gifted a drinking bottle to children (aged 24-48 months) to use for 2 weeks. They returned to perform reach-grasp-lift-replace actions with their own or the experimenter's bottle while we recorded their movements using motion capture. There were differences in motor interactions with self- vs experimenter-owned bottles, such that children positioned self-owned bottles significantly closer to themselves compared with the experimenter's bottle. Age did not modulate the positioning of the self-owned bottle relative to the experimenter-owned bottle. In contrast, the pattern was not evident in children who selected one of the two bottles to keep only after the task was completed, and thus did not 'own' it during the task (Experiment 2). These results extend similar findings in adults, confirming the importance of ownership in determining self-other differences and provide novel evidence that object ownership influences sensorimotor processes from as early as 2 years of age.

Intuitions about personal identity are rooted in essentialist thinking across development

What aspects of a person determine whether they are the same person they were in the past? This is one of the fundamental questions of research on personal identity. To date, this literature has focused on identifying the psychological states (e.g., moral beliefs, memories) that people rely on when making identity judgments. But the notion of personal identity depends on more than just psychological states. Most people also believe that the physical matter that makes up an individual is an important criterion for judging identity; changes to the physical stuff in a person's body, even if they are not accompanied by any psychological changes, are judged to change who the person is at some level. Here, we investigate the sources of these beliefs and propose that they stem from the broader cognitive tendency to assume that unseen physical essences make things what they are-psychological essentialism. Four studies provided support for this claim. In Studies 1 and 2, exposing participants to essentialist reasoning led to stronger endorsement of physical continuity as a criterion for personal identity. Similarly, individual differences in participants' essentialist thinking predicted the extent of their reliance on physical continuity (Study 3), and this relationship was observed even among 6- to 9-year-old children (Study 4). These studies advance theory on the psychology of personal identity by identifying a reason why people assign a central role to physical composition when judging identity.

Children, but not great apes, respect ownership

Access to and control of resources is a major source of costly conflicts. Animals, under some conditions, respect what others control and use (i.e. possession). Humans not only respect possession of resources, they also respect ownership. Ownership can be viewed as a cooperative arrangement, where individuals inhibit their tendency to take others' property on the condition that those others will do the same. We investigated to what degree great apes follow this principle, as compared to human children. We conducted two experiments, in which dyads of individuals could access the same food resources. The main test of respect for ownership was whether individuals would refrain from taking their partner's resources even when the partner could not immediately access and control them. Captive apes (N = 14 dyads) failed to respect their partner's claim on food resources and frequently monopolized the resources when given the opportunity. Human children (N = 14 dyads), tested with a similar apparatus and procedure, respected their partner's claim and made spontaneous verbal references to ownership. Such respect for the property of others highlights the uniquely cooperative nature of human ownership arrangements.

Give and take: Ownership affects how 2- and 3-year-olds allocate resources

In three experiments, we investigated whether 2- and 3-year-olds (N = 240) consider ownership when taking resources for themselves and allocating resources to another agent. When selecting resources for themselves, children generally avoided taking resources that belonged to another agent and instead favored their own resources (Experiments 1 and 2). However, they did not avoid taking the agent's resources when the only other resources available were described as not belonging to the agent (Experiment 3). Children also selected fewer of the agent's resources when taking for themselves than when giving to the agent (Experiments 2 and 3). In giving to the agent, children were more likely to select the agent's resources than resources not belonging to the agent (Experiment 3). These findings show that ownership affects how 2- and 3-year-olds allocate resources. The findings also provide new evidence that 2-year-olds may respect others' ownership rights, at least to a limited degree, although we also consider an alternative explanation for the findings.

Exploring the first possessor bias in children

Even very young children are adept at linking property to owners (Gelman, Manczak, & Noles, 2012). However, some studies report that children systematically conserve property with the first possessors (Blake & Harris, 2009; Friedman & Neary, 2008). The present study seeks to integrate these two findings by testing for the presence of a first possessor bias in older children (ages 7-10) using a broader array of property transfers, and by investigating how manipulations of context-from third-person to first-person-yield ownership attributions that are more or less biased. Seven- and 8-year-olds, but not older children, exhibited a first possessor bias when property transfers were presented in a third-person context. This finding suggests that the first possessor bias persists longer in childhood than previously suspected. However, the bias was greatly attenuated or absent when property transfers were presented in a first-person context, rather than a third-person context.

Ownership Matters: People Possess a Naïve Theory of Ownership

Ownership is at the heart of people's daily activities and has been throughout history. People consider ownership when acting on objects, engaging in financial matters, and assessing the acceptability of actions. We propose that people's understanding of ownership depends on an early-emerging, causally powerful, naïve theory of ownership. We draw on research from multiple disciplines to suggest that, from childhood, a naïve theory of ownership includes ontological commitments, causal-explanatory reasoning, and unobservable constructs. These components are unlikely to stem from other core theories or from noncausal representations. We also address why people might have a naïve theory of ownership, how it develops across the lifespan, and whether aspects of this theory may be universal despite variation across cultures and history.

The role of age, theory of mind, and linguistic ability in children's understanding of ownership

The current study replicates and expands prior work on children’s ownership intuitions and explores whether variability in theory of mind and linguistic ability predicts patterns in children’s understanding of ownership. We tested children ages 4 to 6 and found age-related differences in ownership intuitions, but those differences were not significantly predicted by variability in theory of mind or linguistic ability. This report is the first to specifically investigate the cognitive competencies that contribute to the development of mature ownership concepts, and to replicate many of the core findings in the literature.

Using versus liking: Young children use ownership to predict actions but not to infer preferences

Three experiments show that young children (N = 384) use ownership to predict actions but not to infer preferences. In Experiment 1, 3- to 6-year-olds considered ownership when predicting actions but did not expect it to trump preferences. In Experiment 2, 4- and 5-year-olds, but not 3-year-olds, used ownership to predict actions, and 5-year-olds grasped that an agent would use his or her own property despite preferring someone else's. This experiment also showed that relating an agent to an object interfered with 3- and 4-year-olds' judgments that a more attractive object is preferred. Finally, Experiment 3 found that 3- and 4-year-olds do not believe that owning an object increases regard for it. These findings are informative about the kinds of information children use to predict actions and the inferences they make from ownership. The findings also reveal specificity in how children use ownership to make judgments about others, and suggest that children more closely relate ownership to people's actions than to their desires.

Mine is better than yours: Investigating the ownership effect in children with autism spectrum disorder and typically developing children

Ownership has a unique and privileged influence on human psychology. Typically developing (TD) children judge their objects to be more desirable and valuable than similar objects belonging to others. This 'ownership effect' is due to processing one's property in relation to 'the self'. Here we explore whether children with autism spectrum disorder (ASD) - a population with impaired self-understanding - prefer and over-value property due to ownership. In Experiment 1, we discovered that children with ASD did not favour a randomly endowed toy and frequently traded for a different object. By contrast, TD children showed a clear preference for their randomly endowed toy and traded infrequently. Both populations also demonstrated highly-accurate tracking of owner-object relationships. Experiment 2 showed that both TD children and children with ASD over-value their toys if they are self-selected and different from other-owned toys. Unlike TD children, children with ASD did not over-value their toys in comparison to non-owned identical copies. This finding was replicated in Experiment 3, which also established that mere ownership elicited over-valuation of randomly endowed property in TD children. However, children with ASD did not consistently regard their randomly endowed toys as the most valuable, and evaluated property irrespective of ownership. Our findings show that mere ownership increases preferences and valuations for self-owned property in TD children, but not children with ASD. We propose that deficits in self-understanding may diminish ownership effects in ASD, eliciting a more economically-rational strategy that prioritises material qualities (e.g. what a toy is) rather than whom it belongs to.

When and how does labour lead to love? The ontogeny and mechanisms of the IKEA effect

We elevate our constructions to a special status in our minds. This 'IKEA' effect leads us to believe that our creations are more valuable than items that are identical, but constructed by another. This series of studies utilises a developmental perspective to explore why this bias exists. Study 1 elucidates the ontogeny of the IKEA effect, demonstrating an emerging bias at age 5, corresponding with key developmental milestones in self-concept formation. Study 2 assesses the role of effort, revealing that the IKEA effect is not moderated by the amount of effort invested in the task in 5-to-6-year olds. Finally, Study 3 examines whether feelings of ownership moderate the IKEA effect, finding that ownership alone cannot explain why children value their creations more. Altogether, results from this study series are incompatible with existing theories of the IKEA bias. Instead, we propose a new framework to examine biases in decision making. Perhaps the IKEA effect reflects a link between our creations and our self-concept, emerging at age 5, leading us to value them more positively than others' creations.

Collective Psychological Ownership and Intergroup Relations

Whereas much social psychological research has studied the in-group and out-group implications of social categorization and collective identity ("we"), little research has examined the nature and relevance of collective psychological ownership ("ours") for intergroup relations. We make a case for considering collective psychological ownership as an important source of intergroup tensions. We do so by integrating theory and research from various social sciences, and we draw out implications for future social psychological research on intergroup relations. We discuss collective psychological ownership in relation to the psychology of possessions, marking behavior, intergroup threats, outgroup exclusion, and in-group responsibility. We suggest that the social psychological processes discussed apply to a range of ownership objects (territory, buildings, cultural artifacts) and various intergroup settings, including international, national, and local contexts, and in organizations and communities. We conclude by providing directions for future research in different intergroup contexts.

Developing Digital Privacy: Children's Moral Judgments Concerning Mobile GPS Devices

New technology poses new moral problems for children to consider. We examined whether children deem object tracking with a mobile GPS device to be a property right. In three experiments, 329 children (4-10 years) and adults were asked whether it is acceptable to track the location of either one's own or another person's possessions using a mobile GPS device. Young children, like adults, viewed object tracking as relatively more acceptable for owners than nonowners. However, whereas adults expressed negative evaluations of someone tracking another person's possessions, young children expressed positive evaluations of this behavior. These divergent moral judgments of digital tracking at different ages have profound implications for how concepts of digital privacy develop and for the digital security of children.

Social Traces of Generic Humans Increase the Value of Everyday Objects

Past research finds that people behave as though the particular qualities of specific, strongly valenced individuals "rub off" on objects. People thus value a sweater worn by George Clooney but are disgusted by one worn by Hitler. We hypothesized that social traces of generic humans can also adhere to objects, increasing their value. Experiments 1 and 2 found that simply marking that consumer products (mugs, giftwrap) were made by generic strangers (e.g., "by people using machines" vs. "by machines run by people") increased their perceived value. Experiment 3 demonstrated that this effect was mediated by thoughts about attention the object received from other people, which, in turn, led people to see the object as possessing more positive social qualities (e.g., friendly), increasing valuation. The results suggest that generic humans are perceived positively, possessing warm social qualities, and these can "rub off" and adhere to everyday objects increasing their value.

Dirty Money: The Role of Moral History in Economic Judgments

Although traditional economic models posit that money is fungible, psychological research abounds with examples that deviate from this assumption. Across eight experiments, we provide evidence that people construe physical currency as carrying traces of its moral history. In Experiments 1 and 2, people report being less likely to want money with negative moral history (i.e., stolen money). Experiments 3-5 provide evidence against an alternative account that people's judgments merely reflect beliefs about the consequences of accepting stolen money rather than moral sensitivity. Experiment 6 examines whether an aversion to stolen money may reflect contamination concerns, and Experiment 7 indicates that people report they would donate stolen money, thereby counteracting its negative history with a positive act. Finally, Experiment 8 demonstrates that, even in their recall of actual events, people report a reduced tendency to accept tainted money. Altogether, these findings suggest a robust tendency to evaluate money based on its moral history, even though it is designed to participate in exchanges that effectively erase its origins.

Young children's preference for unique owned objects

An important aspect of human thought is the value we place on unique individuals. Adults place higher value on authentic works of art than exact replicas, and young children at times value their original possessions over exact duplicates. What is the scope of this preference in early childhood, and when do children understand its subjective nature? On a series of trials, we asked three-year-olds (N=36) to choose between two toys for either themselves or the researcher: an old (visibly used) toy vs. a new (more attractive) toy matched in type and appearance (e.g., old vs. brand-new blanket). Focal pairs contrasted the child's own toy with a matched new object; Control pairs contrasted toys the child had never seen before. Children preferred the old toys for Focal pairs only, and treated their own preferences as not shared by the researcher. By 3years of age, young children place special value on unique individuals, and understand the subjective nature of that value.

"Because It's Hers": When Preschoolers Use Ownership in Their Explanations

Young children show competence in reasoning about how ownership affects object use. In the present experiments, we investigate how influential ownership is for young children by examining their explanations. In three experiments, we asked 3- to 5-year-olds (N = 323) to explain why it was acceptable (Experiments 1-3) or unacceptable (Experiment 2 and 3) for a person to use an object. In Experiments 1 and 2, older preschoolers referenced ownership more than alternative considerations when explaining why it was acceptable or unacceptable for a person to use an object, even though ownership was not mentioned to them. In Experiment 3, ownership was mentioned to children. Here, younger preschoolers frequently referenced ownership when explaining unacceptability of using an object, but not when explaining why using it was acceptable. These findings suggest that ownership is influential in preschoolers' explanations about the acceptability of using objects, but that the scope of its influence increases with age.

Keeping Track of Individuals: Insights from Developmental Psychology

According to Mammen and Mironenko (2015) our sensitivity to objects' history (i.e., objects' whereabouts across space and time) has been neglected in much of contemporary psychology. In this paper I present evidence from a developmental psychological perspective indicating that although the terminology is different, some research concerning these important issues has actually been conducted. First, research primarily under the heading 'essentialism' has shown that children are sensitive to at least some aspects of an object's history. Second, research on object individuation has revealed that for infants spatiotemporal information appears to have primacy relative to featural information. Finally, research on episodic development has provided evidence that a continuous (hence historical) sense of 'me' may be a necessary, although not sufficient, precondition in order to have episodic memories. It is argued that the available evidence converges, which only underscores the relevance and importance of the issues raised by Mammen and Mironenko (2015).

Identical but not interchangeable: Preschoolers view owned objects as non-fungible

Owned objects are typically viewed as non-fungible-they cannot be freely interchanged. We report three experiments (total N=312) demonstrating this intuition in preschool-aged children. In Experiment 1, children considered an agent who takes one of two identical objects and leaves the other for a peer. Children viewed this as acceptable when the agent took his own item, but not when he took his peer's item. In Experiment 2, children considered scenarios where one agent took property from another. Children said the victim could take back her own property from the perpetrator, but that she could not take an identical object belonging to the perpetrator. Finally, in Experiment 3A and 3B, children considered scenarios where a teacher could give a child either of two objects to play with-an object that the child had recently played with, or another object that looked the same. Children were more likely to say that the teacher should give the object recently played with when it belonged to the child, compared with when it belonged to the teacher. These findings are informative about the basis of judgments that property is non-fungible, and about young children's representation of ownership rights. They show that children's representation of ownership rights is not limited to principles protecting owners from being deprived. Our findings instead suggest that ownership rights are viewed as pertaining to individual objects.

From Effort to Value: Preschool Children's Alternative to Effort Justification

In the current studies, we addressed the development of effort-based object valuation. Four- and 6-year-olds invested either great or little effort in order to obtain attractive or unattractive rewards. Children were allowed to allocate these rewards to an unfamiliar recipient (dictator game). Investing great effort to obtain attractive rewards (a consonant situation) led 6-year-olds, but not 4-year-olds, to enhance the value of the rewards and thus distribute fewer of them to others. After investing effort to attain unattractive rewards (a dissonant situation), 6-year-olds cognitively reduced the dissonance between effort and reward quality by reappraising the value of the rewards and thus distributing fewer of them. In contrast, 4-year-olds reduced the dissonance behaviorally by discarding the rewards. These findings provide evidence for the emergence of an effort-value link and underline possible mechanisms underlying the primacy of cognitive versus behavioral solutions to dissonance reduction.