Tag Archives: developmental psychology

Ownership in children’s justifications. Friedman and Nancekivell

Nancekivell, S. E., Van de Vondervoort, J. W., & Friedman, O. (2013). Young Children’s Understanding of Ownership. Child Development Perspectives, 7(4), 243–247.

This study uses a very simple experimental design to explore how children (ages 3 through 5) use ownership in their explanations about why it is acceptable or unacceptable for a person to use an object. They do three experiments.

In the first two experiments, ownership is not mentioned to children, and researchers test whether children bring up ownership spontaneously in their explanations.

In Experiment 1, researchers focused on the “right of use”, that is, whether it is acceptable for a certain character to use a certain object.

Experiment 2 is similar to experiment 1, but it focuses on the “right of exclusion” (someone shouldn’t use something because it belongs to someone else).

Experiment 3 provides children with explicit information about ownership before asking about acceptability and unacceptability of use.

The conclusions are that, as children grow older, they become more likely to use ownership to explain why it acceptable or unacceptable to use an object. 3-year-olds rarely referenced ownership, while 5-year-olds referenced ownership in almost half of their explanations. 5-year-olds gave ownership explanations more than any other particular kind of explanation (and this is not the case in younger children).

4- and 5-year-olds gave ownership explanations at similar rates regardless of whether ownership was mentioned. However, whether ownership was mentioned (experiment 3) did influence 3-year-olds: When 3-year-old explained why it was unacceptable to use an object, they referenced ownership more often when it was mentioned than when it was not mentioned. 3-year-olds gave more ownership explanations in the unacceptability-of-use condition.

We should emphasize that it all hangs in the narrative context. Children might reference ownership more if asked about why a person is allowed to modify an object; but they might reference ownership less if asked about gender typed objects or objects that are potentially dangerous, as other explanatory factors might be more compelling for such items (i.e., gender norms; safety concerns).

I’m interested in this topic because I think that ownership plays an important role in the development of reasoning. Rather thank considering reasoning as a cognitive, cold faculty that is applied to the domain of ownership, I believe that reasoning develops in the context of the rhetorical fight for object possession (competition, sharing, adjudication of ownership, etc.) Children feel authorized to give permission, forbid, and reason about objects in general in so far as they can appropriate those objects and feel that they are their own. The fact that ownership appears spontaneously in children’s reasoning is therefore relevant for my research interests.

Ultimatum and dictator in four-year-olds

Lucas, M., Wagner, L., & Chow, C. (2008). Fair game: The intuitive economics of resource exchange in four-year olds. Journal of Social, Evolutionary, And, 2(3), 74–88. Retrieved from http://137.140.1.71/jsec/articles/volume2/issue3/JSEC2-3_Lucas.pdf

This is an interesting paper in an area that needs more research, namely, how children perform in economic games. The typical questions go as follows: Are children altruistic? Are they selfish?

The authors review and criticize some of the relevant previous research. Murnighan & Saxon (1998) found that kindergartners made larger ultimatum offers and accepted smaller ultimatum offers of candy than did third or sixth graders. However, Lucas et. al argue that Murnighan & Saxon’s results are probably not valid since they use a kind of simulated game, in which the child is asked to imagine that another child offers such and such amount of candy (instead of actually playing the ultimatum game). They also quote Harbaugh, Krause, & Liday (2003), who found that seven-year olds made and accepted smaller ultimatum proposals than adults; and Hill and Sally (2006), who found that 6-year-olds already make offers as fair as those of adults after repeated rounds of play. Benenson, Pascoe and Radmore (2007), on the other hand, found that very young children can be altruistic when playing dictator (4-year-olds donated, on average, 25% of a stake of ten stickers to another classmate).

The authors also mention a problem with some of the previous research: often, researchers make children play with tokens that have no inherent value; children are explained that they will be able to trade the tokens for other stuff later. Lucas et al. argue that researchers should use items with tangible, real value for children, such as candy, stickers or toys, since the use of “symbolic” tokens poses additional cognitive demands on children and might affect experimental results.

Lucas et al. found, in their own study, that children made, on average, offers of 4.7 stickers in the ultimatum game and 3.99 stickers in the dictator game. That is, children seem to be making quite fair offers.

It is well established that adults give an average of 40% of the money at stake in ultimatum. But there is a big difference between the 4-year-olds’ 47% and the adults’ 40%. In adults, the mode (i.e., the most frequent answer) is 50%, while some adults give 40%, 30% or less, and almost no one offers more than 50%. However, some of Lucas el al.’s 4-year-olds offer more than 50%.  They call this phenomenon hyperfair offers. There is a qualitative difference between adults and children: adults oscillate between the fair (“half and half”) and the strategic (“less than half”). Many children, by way of contrast, offer more than is fair, more than half the stake.

“(…) the percentage of hyperfair offers (…) increased from 18% in the dictator game to 33% in the ultimatum game. Adults, in contrast, almost never make hyperfair offers (only 3.5% of offers in Lucas, Et al., (2007) were hyperfair).”

Lucas et al. also report that, in their study, children did not seem to take into account the behavior of the other player in their responses, even if it was unfair. In the dictator game, children did not change the amount of their offer in response to receiving either a low or fair offer from the friend. Children’s offers for the second game were also not affected by whether the friend had accepted or rejected the child’s first offer.

The results of the dictator game suggest that children in the sample are quite altruistic: “The adult average offer of 20% of the stake in the dictator game (Camerer, 2003) is usually interpreted as evidence that individuals have preferences for altruism, since proposers could offer less in a dictator game without fear of rejection. With an average offer in the dictator game of 40% of the stake, our sample of children made more altruistic offers than adults.”

Children’s average offer of 4 stickers (or 40% of the stickers at stake) doubles adults’ typical offer of 20% of the money at stake in dictator, and does not seem to far away from the 47% children offered in the ultimatum game. How do Lucas et al. explain these data? “(Children’s) ability to perform a cost/benefit analysis was limited. They did not seem to appreciate the degree to which they could “shade” their offers without penalty.” Thus, Lucas et al. are assuming that children have the desire or goal of keeping as many stickers as possible but they that their strategic thinking is deficient. “Children were more generous than they needed to be and were limited in their ability to act strategically in bargaining games in order to maximize their own benefits while avoiding the costs of rejection.”

Lucas et al.’s conclusion: “children are quite altruistic”, “they may have an innate sense of fairness and altruism.” This result is, in my opinion, over-simplistic. Previous research in economic psychology has established that adults are altruistic and fair to some degree, but also a little bit selfish and strategic. Lucas et al. assume, therefore, that either children are born altruistic, fair and strategic or they learn these behaviors along the way. If research shows that children are completely selfish, then altruism is learned. If it shows they are altruistic from the start, then it must be innate.

I quote them: “We predicted that children would perform similarly to adults in showing preferences for fairness and altruism. Alternatively, and as some others have found, children could be less fair, indicating that fairness must be learned over the course of development.”

They start with a binary opposition between selfishness and altruism. In this approach, learning is seen as lineal, cumulative, unidirectional. They start with some innate concepts and, while learning, children simply absorb information from their milieu or copy adult models, until they reach the end-point.

There are other possibilities, however. For example: young children might be neither selfish nor altruistic. They might be following other types of reciprocity not related to the fair, contract-like, 50/50 reciprocity of adults. They might use an associative reciprocity of the kind “I give a lot of stickers to the other kid because I like to make friends” (see Faigenbaum, 2005), that are typical of children’s peer cultures and of exchanges within the family. Such an approach dispels the apparent inconsistencies of previous research: it’s not just that children are not yet able to think “strategically”. They are not even interested in this kind of reasoning.

Associative reciprocity might explain why kindergartners make large ultimatum offers and accepted small ultimatum offers of candy (Murnighan & Saxon, 1998) or why 4-year-olds can be so altruistic when playing dictator (Benenson, Pascoe and Radmore, 2007). It might also explain the results of Lucas et al.’s own research, for example, why children give 40% of the stake in the dictator game.

Some references

Faigenbaum, G. (2005). Children’s Economic Experience: Exchange. Buenos Aires: LibrosEnRed.

Harbaugh, W. T., Krause, K. S., & Liday, S. J. (2003). Bargaining by Children. Social Science Research Network, 1–40. https://doi.org/10.2139/ssrn.436504

Lucas, M., Wagner, L., & Chow, C. (2008). Fair game: The intuitive economics of resource exchange in four-year olds. Journal of Social, Evolutionary, And, 2(3), 74–88. Retrieved from http://137.140.1.71/jsec/articles/volume2/issue3/JSEC2-3_Lucas.pdf

Murnighan, J. K., & Saxon, M. S. (1998). Ultimatum bargaining by children and adults. Journal of Economic Psychology, 19(4), 415–445. https://doi.org/10.1016/S0167-4870(98)00017-8

Exploring the first possessor bias in children. Nole & Keil.

Noles, N. S., & Keil, F. C. (2019). Exploring the first possessor bias in children. PLoS ONE, 14(1), 1–13. https://doi.org/https://doi.org/10.1371/journal.pone.0209422

Very interesting and insightful paper. The authors set out to explore an apparent contradiction: on the one hand, very young children (even 2-year-olds in some studies) are adept at linking property to owners. On the other, there is research that reports that children systematically conserve property with the first possessor, even after a legitimate transfer of the property to a second possessor (e.g., after a sale, a present).

This study tests children, ages 7 through 10, for the presence of a first possessor bias in first- and third-person situations, and for different types of property transfers (gift, sale, loss, etc.)

A first experiment used third-person scripts depicting different types of property transfers. The authors found that seven- and eight-year-olds, but not older children, exhibited a first possessor bias. “Children under 9 commonly inferred that first-possessors maintained ownership of property, even after they unambiguously transferred the property to another person.” “Experiment 1 reveals that the first possessor bias influences ownership attributions among children age 7 and 8, but not 9 and 10.” “Experiment 1 demonstrates that the first possessor bias persists much longer into development than previously thought.” “This result replicates previous findings and expands upon those studies, suggesting that the first possessor bias influences a wider swath of property transfers than previously demonstrated, and that children’s ownership attributions are affected by this bias for longer than previously reported.”

At the same time, they found that the bias was greatly attenuated or absent when property transfers were presented in a first-person context. This was demonstrated in a second experiment, in which “Participants were always framed as the recipients or second actor in each scenario, and they were asked who owned the target object at the end of each trial. Participants indicated that the item either belonged to them or to the experimenter.” “In Experiment 2, all age groups demonstrated attenuated endorsement of the first possessor with respect to stealing (…) context powerfully influences intuitions about property transfers in both children and adults.” “Experiment 2 provides an explanation for the mismatch between intuitions that children do understand property transfers early in development, and findings that children’s intuitions about property transfers are fundamentally biased. Specifically, manipulating the presentation context (i.e., presenting transfers in a first-person context) resulted in children generating adult-like ownership attributions for typical property transfers such as giving and selling.”

One important consequence for the study of the development of ownership is that there is a big gap between first- and third-person reasoning. Thus one can reconcile research by Rossano, Rakoczy, & Tomasello (2011) among others, that shows that 3-year-olds recognize property rights when laboratory situations resemble real-life situations, with other studies which use third-person narratives and find errors in reasoning about property rights in children until at least age 10 (Kim & Kalish, 2009).

The authors speculate that the first-possessor bias has adaptive value: “it is possible that young children are less adept at reasoning about property transfers because these events are more ambiguous, and more likely to be intervened upon, than non-transfer scenarios. Given these circumstances, maintaining strong bonds between owners and their property may be a more functional approach for young children than reasoning in a more adult-like and “accurate” manner.”

Kim, S., & Kalish, C. W. (2009). Children’s ascriptions of property rights with changes of ownership. Cognitive Development, 24(3), 322–336. https://doi.org/10.1016/J.COGDEV.2009.03.004

Noles, N. S., & Keil, F. C. (2019). Exploring the first possessor bias in children. PLoS ONE, 14(1), 1–13. https://doi.org/https://doi.org/10.1371/journal.pone.0209422

Rossano, F., Rakoczy, H., & Tomasello, M. (2011). Young children’s understanding of violations of property rights. Cognition, 121(2), 219–227.

Egalistarism and parochialism in young children

Fehr, E., Bernhard, H., & Rockenbach, B. (2008). Egalitarianism in young children. Nature, 454(7208), 1079–1083. http://doi.org/10.1038/nature07155

This is a classic and crucial study. The authors use an extremely simple experimental design (inspired in previous work with non-human primates) to test the hypothesis of a parallel development of children’s egalitarianism and parochialism. Children between 3 and 8 years of age are presented three situations:

  • Prosocial: either take one candy and assign one candy to another child, or take one candy and assign none to another child ((1,1) vs. (1,0).
  • Envy: either take one candy and assign one candy to another child, or take one candy and assign two candies to another child ((1,1) vs. (1,2).
  • Costly sharing: either take one candy and assign one candy to another child, or take two candies and assign none to another child ((1,1) vs. (2,0).

The study shows that children, as they grow, aim at reducing the inequality between themselves and their partner, regardless of whether the inequality is to their advantage or disadvantage.

The authors found that children at age 3–4 show little willingness to share resources (as tested by the sharing situation) but a non-negligible percentage of the children is willing to make choices that benefit the recipient if it is not costly (in the envy and prosocial situations). After this age, other-regarding preferences develop, which take the form of inequality aversion instead of a preference for increasing the partner’s or the joint payoff.

Thus, across the three situations, egalitarian choices increase with age. “If we pool the children’s choices in all three games, the percentage of children who preferred the egalitarian allocation in all three games increases from 4% at age 3–4 to 30% at age 7–8.” Also, “(…) the share of subjects who maximize the partner’s payoff by choosing both (1,1) in the prosocial game and (1,2) in the envy game decreases sharply from 43% at age 3–4 to 16% at age 7–8.” Egalitarianism rises as generosity declines.

This emphasis on equality (or inequality aversion) seems to be uniquely human; no animal shows a comparable behavioral pattern.

In addition, children (especially boys) seem to show an in-group bias. For example, in the envy game, boys tend to do egalitarian distributions (1,1) rather than generous distributions (1,2) more with the outgroup than with the ingroup. The effects of parochialism are also apparent in the other situations: In the prosocial game, the children remove inequality that favors themselves more often if the partner is an ingroup member. In the sharing game, egalitarian choices slightly decrease over time if the partner is an outgroup member, whereas sharing with ingroup members strongly increases with age

The conclusion is not only that egalitarianism and parochialism are important forces driving children’s judgments, but also that is that a utilitarian ethics seems absent from children’s minds. In other words, children do not try to maximize the total sum of benefits for everybody. That is why, in the “envy” situation, children (at least after 5 or 6 years of age) tend to prefer (1,1) over (1,2); that is, egalitarianism trumps maximization of benefits. Utilitarianism is not a factor in children’s reasoning. Equality aversion and parochialism grow between 3 and 8 years of age and explain children’s responses.

Comparing this paper with other studies, it is interesting to note that equality is said to appear at 5, or 6, or 7 or 8 years of age depending on the study, the methodology used and the way the results are interpreted (e.g., Rochat says that children at 5 are already steady defenders of strict equality and that they even can adopt an ethical stance, when they are willing to sacrifice their own resources to punish an agent that is not observing equality).

In addition, it is relevant to understand young children’s (3 and 4 year-olds) apparent discrepant or erratic behavior (sometimes they are generous, at other times they are selfish). In a previous study I claimed that the reason for this is that those children “don’t frame their relationships in terms of strict-reciprocity (tit for tat) contracts. It should be no surprise that their behavior in economic games and fairness experiments is consistent with a culture of associative reciprocity and the gift economy, which predominate in the context of familial institutions and peer relationships at this age. Preschoolers might appear as non-strategic from the point of view of economists who identify rationality with calculating the best means to achieve a desired end-result (individual profit, equality, etc.), but they are actually well adapted to their real social context. (…)  The apparently selfish tendencies of 3-year-olds moderate themselves as children mature, so that between five and seven years of age (depending on the specific study) children start demanding fairness and rejecting inequality. In certain cases, they even embrace an ethical stance and engage in costly punishment. This emerging mindset is in harmony with the strict reciprocity embedded in experiences such as bartering with peers or dealing with money and prices, which gain prominence in children’s daily life as they grow up. In the culture of adults, barter and monetary transactions are considered fair when both parties receive an equivalent value. Similarly, fair distributions between partners with the same merit are expected to be 50/50. This kind of institutional context comes to dominate children’s interactions and provides them with a new sense of fairness.”

Bakeman & Brownlee: Social rules governing object conflicts in toddlers and preschoolers

Bakeman, R., & Brownlee, J. R. (1982). Social rules governing object conflicts in toddlers and preschoolers. In Peer relationships and social skills in childhood (pp. 99–111). New York: Springer Verlag.

I’ve seen this article quoted over and over again as one of the first serious studies on ownership in children. I finally was able to read it, and I am very impressed both by the empirical study and the theoretical reflections.

On the theoretical level, the authors hypothesize that young children are capable of developing rules to regulate interaction with their peers, “as a consequence of a fundamental human propensity to regulate social interaction in a ruleful manner”. They say children do this “not as a result of cultural intervention.” What they seem to mean is not that rules are a natural phenomenon developed outside of culture, but that children tend to develop rules spontaneously, independent of explicit adult teaching. I believe that the authors would accept the proposition that rules are developed in the context of peer-culture. The important point Bakeman and Brownlee are making is that normativity is present in human interaction very early (during the second year of life).

The authors see possession episodes (interactions in which a child tries to take an object from another child) as a privileged source to obtain examples of early rules. We know that 18 month-olds already use the possessive “mine” in the context of their frequent possession struggles. Such disputes are often the occasion of adult intervention and rule stating. For all these reasons, possession is “the place” where one should look for children’s first rules.

In their empirical work with possession episodes, the researchers focus on two types of data: the rate of success by object takers and the rate of resistance attempts by object holders.

The main finding of this study is that prior possession influences the outcome of possession episodes. If a taker has had prior possession of the object, then her take attempt is more likely to succeed. The outcome of possession episodes among children in the second, third, and fourth year of life is not simply a matter of individual power, but can be at least partly explained by reference to the prior possession rule. The researchers also found that one year olds are as likely to resist a taker who has had prior possession as not, while three year olds were less likely to resist a taker who has had prior possession. This suggests that among the three year olds the prior possession claim may have been recognized by both children, at least at a point sufficiently early in the taking so that active resistance was less likely.

However, rule observance is not the only possible explanation for children’s behavior. Perhaps if a child has played with a toy recently, she is more likely to prefer that toy to others and hence to expend more effort in its recovery. Other children might eventually acquiesce to this more vigorous onslaught, what the authors call the ”vigor of desire.” Later, children may come to resist the prior possessing taker less, not because they have accepted a social rule, but only because they have learned about the negative consequences associated with this situation.

The authors, then, admit that there is no definitive way to decide between a “social learning” and a “shared rule” interpretation of the facts, especially in the one-year-olds. The situation is somewhat less ambivalent in the three-year-olds, because they are less likely to resist a taker who has had prior possession independently of their dominance, therefore they do not seem to be simply avoiding conflict. More importantly, the authors also claim that the difference between the two interpretations may be more apparent than real. I agree with this. The fact that children resist less when the taker is a prior possessor might reflect both a tendency to avoid conflict and a spontaneous way of regulating peer interaction. In other words, what we are dealing with here are rules at their very birth.

At the end of the article there are a couple of beautiful paragraphs that clearly express the authors’ outlook: “Young children are neither nasty brutes who must have rules imposed upon them nor noble savages who come with a built-in sense of equity; rather, they are adaptive, socially sensitive organisms trying to get along in a social world full of conflicting needs and limited resources. They may have a far greater capacity for ruleful regulation of their social affairs than we usually grant them, a capacity which only careful observations of young children playing with their age-mates is likely to reveal.”

Bakeman and Brwonlee are pioneers. Apparently they are the first who studied the prior possession rule in children. I used to think that Hildy Ross was the first. The findings are the same: even 18 month old toddlers seem to observe a basic version of the prior possession rule.

Elliot Turiel on the Development of Morality

Turiel, E. (2008). The Development of Morality. In W. Damon & R. M. Lerner (Eds.), Child and Adolescent Development: An Advanced Course (pp. 473–514). SAGE Publications.

This is a great summary of trends and theoretical orientations in the study of moral development by Elliot Turiel. I will only comment on a couple of minor points.

First: I like the fact that Turiel considers children as active social agents that face conflicts and meaningful moral experiences in their everyday life. Moral development is not about absorbing information about moral rules or values, it is about actively constructing a moral understanding of the social world and of one’s own life. “…in many current formulations morality is not framed by impositions on children due to conflicts between their needs or interests and the requirements of society or the group. Many now think that children are, in an active and positive sense, integrated into their social relationships with adults and peers and that morality is not solely or even primarily an external or unwanted imposition on them.”

He also emphasizes that morality is not primarily negative (as one might infer from Freudian or behavioristic formulations); in other words, it’s not about the inhibition of aggressive or sexual impulses. Today, we know that children experience empathic feelings towards other people spontaneously; that our species has a natural tendency to do things within groups and to help each other. “The findings that young children show positive moral emotions and actions toward others indicate that the foundations of morality are established in early childhood and do not solely entail the control and inhibition of children’s tendencies toward gratifying needs or drives or acting on impulses. However, that the foundations of positive morality are established in early childhood does not necessarily establish that significant aspects of development do not occur beyond early childhood; that judgments, deliberations, and reflections are unimportant; or that many experiences, in addition to parental practices, do not contribute.”

Against the work of J. Haidt and R. Shweder, Turiel claims that:

“Studies of moral development suggest alternatives to the propositions that emotions are primary in morality, that moral acquisition is mainly due to effects of parental practices on children, or that morality largely reflects the acquisition of societal standards. Dunn et al. (1995) found differences in the two types of situations they assessed (physical harm and cheating) and documented that relationships with siblings influence development.” This suggests that children have a spontaneous capacity to reason according how they determine the domain they are dealing with (moral, societal, personal) or the kind of moral problem at hand.

Children do not receive passively the moral prescriptions upheld by adults; rather, they show a certain degree of autonomy early on. “By 2 or 3 years of age, children display a fair amount of teasing of mothers, physical aggression, destruction of objects, and an increasing ability to engage in arguments and disputes with mothers (Dunn & Munn, 1987). This increasing variety in young children’s social relationships is consistent with the findings reviewed by Grusec and Goodnow (1994) showing that parental practices are related to type of misdeed (e.g., moral or conventional), children judge the appropriateness of reasons given by parents when communicating with them, and parents may encourage ways of behaving that differ from those they engage in themselves… With acts entailing theft or physical harm to persons, young children (4 to 6 years) give priority to the act itself rather than the status of the person as in a position of authority.”

“Children’s judgments are not based on respect or reverence for adult authority but on an act’s harmful consequences to persons. Children’s judgments about harmful consequences emerge early in life along with emotions of sympathy, empathy, and respect (Piaget, 1932; Turiel, 2006b); at young ages children go well beyond social impulses and the habitual or reflexive, attempting to understand emotions, other persons, the self, and interrelationships (Arsenio, 1988; Arsenio & Lemerise, 2004; Nucci, 1981; Turiel, 1983, 2007). A great deal of research has demonstrated that young children make moral judgments about harm, welfare, justice, and rights, which are different from their judgments about other social domains.”

All this is consistent with my view of children as active, institutional agents.

Turiel notices that the differentiation between the societal, personal and moral domains appears early in life (at three years of age) but that doesn’t mean that it’s innate. Rather, he believes it might originate in the experiences and interactions children engage in during their first years.

Children see property as nonfungible

 

McEwan, S., Pesowski, M. L., & Friedman, O. (2016). Identical but not interchangeable: Preschoolers view owned objects as non-fungible. Cognition, 146, 16–21. http://doi.org/10.1016/j.cognition.2015.09.011

This is another great article by Ori Friedman’s team. They did three experiments to find out whether children see owned objects as fungible (i.e., as replaceable or interchangeable). In Experiment 1, children considered an agent who takes one of two identical objects and leaves the other for a peer. When considering a scenario where a boy took one of two identical objects home, and left the other for a girl, preschoolers viewed his behavior as more acceptable when he took his own item, rather than the girl’s.

In Experiment 2, children considered scenarios where one agent took property from another. When considering a scenario where a boy deprived a girl of her balloon, preschoolers judged it acceptable for the girl to take back her own balloon; but they judged it unacceptable for her to take the boy’s balloon, even though it was the only balloon available to compensate her.

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. When considering a scenario where a teacher could give a boy one of two identical-looking balls to play with, preschoolers were more likely to say she should return the ball that the boy had previously played with when it belonged to him, compared with when it was her own.

These findings indicate that children see property as non-fungible.

Previous studies showed that children at these ages show concern for owners’ rights to an object. McEwan et al.’s findings extend knowledge by showing that these concerns persist even when an identical replacement is available to the other. The fact that children at these ages already show intuitions of non-fungibility indicates that such intuitions are an early development, and perhaps foundational in people’s reasoning about ownership. People view ownership as granting people rights to particular objects (i.e., rather than to objects of a certain type).

These are all very relevant and important findings that add detail to current knowledge about the development of ownership.

One conceptual doubt. The fact that children say that it’s not ok to take the perpetrator’s object may not mean that children literally see identical objects as interchangeable. In my opinion, this last statement presupposes a “physicalist” view of the world, understood as a collection of free floating objects with certain physical characteristics that make them different or identical, and placed in certain positions within a 3D space. An alternative view is that children, when they respond to the interviewer, are judging the actions and intentions of the characters, in the context of a social situation that includes objects. And, as Gelman says, objects have histories. So children may think something like “it’s not ok to take someone else’s property even if they took yours first”. It is also more likely that they think in terms of particular objects, not in terms of classes or categories of objects. So the concepts of “identical” or “interchangeable” may not play a role in children’s reasoning. Also, the difference between responses to the balloon situation and the cookie situation might be due to the fact that children take into account the actions of the perpetrators, and perhaps her intentions. It’s not the same popping a balloon accidentally than eating a cookie purposefully.

Great article.