Category Archives: developmental psychology

Susan Gelman on children’s preference for unique owned objects

Gelman, S. A., & Davidson, N. S. (2016). Young children’s preference for unique owned objects. Cognition.

This is an incredible and profound study on children’s attachment to objects, with implications both for cognitive and emotional development. It’s also a study that amazes me for the amount of work it required from researchers (who had to find brand-new replicas of more than 100 children’s attachment objects).

The experimental design is quite simple. Researchers asked 36 three-year-olds 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 an old toy that belonged to the child with a matched new object; control pairs contrasted toys the child had never seen before.

The conclusion of the study is that, by 3 years of age, young children place special value on unique owned objects. Children prefer their original objects to newer, better versions, but only in the case of the focal pairs (with their objects of attachment) and not with the control pairs (objects the child had never seen before). These findings are consistent with the view that possessions are extensions of the self.

In addition, these preferences hold for “sleep” objects (blanket, pillow) and toys representing an animated character (dolls, action figures) but not for inanimate objects (a car, a toy hammer, etc.) Uniqueness is valued for sleep objects and animate toys, but not for inanimate toys. Moreover, in 30 out of 31 cases, attachment objects had a proper name. Ownership, attachment and anthropomorphism (eyes, animated features, soft or furry texture) all combine to enhance children’s preferences for their own objects.

In addition, children seemed to understand that their special objects had value for them only in so far as they share a history with the object. That is, they did not attribute the researcher the same preference for the old (attachement) object. In this sense, they seem to understand the subjective nature of value.

The results are remarkable, among other things, because of the understanding of the abstract ownership relationships, the distinction between appearance and reality and the perspective-taking abilities involved in children’s responses. The authors also emphasize how attuned any child can be to minor features of an object that indicate that it is her unique object and not a substitute.

These findings also offer a different (experimental, cognitive) perspective on the phenomenon of “transitional objects,” first described by Donald Winnicott in the 1950s.

A remarkable study indeed.

Paulus & Moore On Recipient-Dependent Sharing Behavior and Expectations

This study aimed at investigating developmental changes in 3-, 4-, and 5-year-old children’s sharing behavior and their expectations of others’ sharing. Children were administered two tasks. In the Self task, they could distribute valuable items between themselves and a friend or a disliked peer; in the Other task, they were asked to predict how another agent would distribute valuable items between himself and a friend or a disliked peer. Additionally, whether sharing was costly for the agents or not was manipulated. Three results:

  1. Basic prosocial orientation: Children of all age groups behaved more prosocially and expected more prosocial behavior from another protagonist when the choice bore no cost. This is kind of an obvious result in view of the existing literature. Previous studies have shown that children act prosocially from early on and distribute resources equally between others. Children also have a corresponding expectation that others will behave prosocially. Even 2-year-olds show a sensitivity for equal distributions in a looking-time task. By 3 years, children showed a general disposition to expect that someone will share with others; at this age, children possess an undifferentiated expectation that humans behave prosocially toward each other.
  2. Recipient-dependent sharing: However, 4- and 5-year-old children, but not 3-year-old children, differentiated between a friend and a disliked peer as potential recipients in the sharing and the sharing expectation tasks. Thus, the study found developmental changes, with 3-year-old children not differentiating between different recipients (the 3-year-old children decided to act prosocially in the majority of trials) and 4- and 5-year-old children showing a clear differentiation. The 4- and 5-year-old children expected someone to share more with a friend than with a disliked peer, indicating specific expectations of how the relationship between an agent and another person affects the probability of showing prosocial behavior. This shows that the undifferentiated expectation that people generally share with others becomes differentiated in the course of the preschool period.
  3. Relationship between first-person behavior and third-person expectations: The same developmental trend was found for children’s own sharing and their expectations of other people’s sharing behavior, suggesting that both show a parallel developmental progression on a group level. Moreover, at 5 years of age, but not at 3 or 4 years, sharing behavior and sharing expectations were on a personal level closely related to each other. In other terms, a within-subject relation was found between 5-year-old children’s own sharing behavior and their sharing expectations. In conclusion, the relation between sharing behavior and sharing expectations emerges strongly at 5 years of age.

Egalistarism and parochialism in young children

Fehr, E., Bernhard, H., & Rockenbach, B. (2008). Egalitarianism in young children. Nature, 454(7208), 1079–1083.

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.”

Use, possession, ownership. An ongoing conversation with P. Kanngiesser

Recently Patricia Kanngiesser sent me a copy of the intro to her doctoral thesis, “Biological and Developmental Origins of Ownership Concepts.” I really enjoyed reading it. It’s extremely well written and well argued. She provides a number of new insights on the development of ownership with great clarity. It’s just brilliant.

One of the important topics Patricia addresses is the conceptual distinction between possession and property. She argues that, while possession presupposes physical proximity between possessors and their things, ownership holds even in the owner’s absence. Possession requires the simultaneous presence of owners and their objects, ownership does not.

Based on this distinction and on extant research on ownership in animals and humans (children and adults), she claims that animals show only possession-related behavior that is crucially dependent on an animal being in physical proximity to a thing. In other words, ownership is absent in animals; animals display rudimentary precursors of ownership-related behaviors only.

“While animals show attachment to things such as territories, food, and mates, evidence for recognizing possession and respecting others’ possessions irrespective of factors such as dominance rank or competitive advantages is sparse. Apart from one rare example of respect for possession of females in baboons, most respect for possession seems to derive from the fact that possessors manage to avoid dominant rivals (e.g. by carrying possession away). Finally, universal social rules regarding ownership are absent from animal societies. While attachment to things could form a biological basis for ownership-related behaviors in humans, an ownership concept that encompasses recognition and respect of ownership as well as a complex web of social rules is probably the unique product of a human socio-cultural environment.” (Patricia Kanngiesser, doctoral thesis).

Up to here I summarized Patricia’s position, and I agree with her. Now, it must be noted that even animal possession is not a two-term relationship (between an individual agent and a thing) but always presupposes a social context. There are possession conflicts because there are individuals competing for objects and for recognition, or for “prestige” as Philippe Rochat would say. PK notes that “about 75% of young children’s conflicts with peers revolve around the possession of objects” and that “21-month-olds often view a toy as more attractive after another child has named or touched it” (Hay & Ross, 1982). Objects become desirable because they are desired by other children; once a child children obtains an object, she wants to be recognized as possessor by other children; she now has exclusive access to the object and can exclude other children. As PK writes, “it is thus conceivable that conflicts concerning the possession of objects are also driven by social motives such as establishing social relationships and exerting social influence.” This, again, suggests not a dual relationship agent-object but at least a triadic relationship agent-object-agent.

Furthermore, PK also notes that “prior possession presents an advantage in conflicts over objects”, a finding corroborated many times both with young children and with some animal species. Now, if current possessors tend to win possession conflicts, it’s because other agents can identify them as possessors. Which again suggests not a dual relation agent-object but a triadic relation where other agents can identify possessors and interact with them accordingly. In this incipient relationship between a non-possessor and a possessor, even if “universal rules” are still absent (as PK argues), there is something like a proto-rule at work: perhaps for strategic reasons that can be modeled in terms of game theory (costs of trying to take an object from a possessor are high), perhaps for efficiency reasons (groups are more stable when possessors are not attacked and conflicts are minimized), current possession is respected, which might be a precursor of institutional or conventional rules such as the prior possession rule (which establishes that prior possession is a justification for ownership).

Therefore, I stick with my position that you need to discriminate three different categories:

– Use: dual relationship between an agent and an object (food, toy, instrument, etc.)

– Possession: triadic relationship agent-object-agent that requires one agent (called the possessor) physically controlling the object, while the other agent is excluded from this relationship. In this scenario, some proto-rules start to play out.

– Ownership: a relationship between agent and object that is not based in physical control but in normative rules (“universal” rules, as PK calls them). The title of owner gives the owner privileged access to the object and, in general, a number of rights and duties.


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.

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.

Children value ideas over labor

Text #15

Li, V., Shaw, A., & Olson, K. R. (2013). Ideas versus labor : What do children value in artistic creation ? COGNITION, 127(1), 38–45. doi:10.1016/j.cognition.2012.11.001

The procedure is simple: have an adult direct a child making a work of art (so that the adult is contributing the guiding ideas while the child is contributing “brute” labor). Then, reverse the roles: have the child supply the guiding idea while the adult follows directions and executes the work of art. Finally, have the child chose which final product she prefers to take home with her: the one that incorporated her effort or the one that reflects her idea?

In a second experiment, the researchers used a similar situation but now they tricked the subjects so that children believed that the drawing contained their ideas when it actually contained the adult’s idea (and vice versa, they believed that the drawing which they had actually created while being directed by an adult was the one that incorporated their ideas).

In a third experiment, they used a third person narrative to lay out a comparison between someone who contributes labor and someone who contributes ideas to the creation of an object. Who should keep the resulting product?

These studies demonstrated that by 6 years old, children value ideas over physical labor. Six year olds systematically chose pictures that contained their own ideas over pictures that contained their labor, even when they were merely tricked into believing that they had come up with the idea for a picture that they had not. Further, 6 year olds demonstrated a general appreciation of ideas – they not only valued their own ideas (Studies 1 and 2), but also privileged idea creators over laborers in a property dispute (Study 3). In contrast, 4 year olds appear to have preferred pictures that contained their specific idiosyncratic preferences. Four year olds preferred pictures containing their ideas, but also their idiosyncratic preferences in Study 1 and pictures they believed contained their labor but also their idiosyncratic preferences in Study 2. Further supporting this possibility, in Study 3 where idiosyncratic preferences could not play a role in selection, 4 year olds showed no bias for either a third-party idea creator or laborer. Six year olds, by way of contrast, sided with the idea creators in third-party case, even when they personally had no connection to the idea.

The age effect in these studies may exist because 6, but not 4 year olds, understand that ideas are valuable and can thus be owned.

In conclusion, the tendency to value ideas is present in childhood and may emerge between 4 and 6 years old. 6 year olds value ideas over labor even when making third-party judgments, favoring those who only contributed ideas as more deserving of a picture over those who only contributed labor.