Ownership is an interesting concept. Unlike many other aspects of objects, ownership depends on the history of the object rather than its features. If you go to a store looking at shirts, the shirts there all belong to the store. If you purchase one (by trading money for the shirt), then it becomes yours. You get to keep the shirt unless you transfer that ownership to someone else.
Sometimes, this can get a little complicated. For example, a woman went to a flea market in West Virginia in 2010 and paid $7 for a box of stuff. Inside the box was a painting that turned out to be a Renoir. The woman planned to sell the painting at auction. However, the Baltimore Museum of Art provided documents suggesting that the painting was stolen from that museum in 1951. As a result, the auction was put on hold. So, who owns the painting?
A nice set of studies in the October, 2012 issue of Child Development by Susan Gelman, Erika Manczak, and Nicholaus Noles explored whether children are able to use aspects of an object's history to determine who owns it. They tested 2- and 3-year-old children.
They examined this question in two ways.
In one study, children sat at a table with an experimenter. On a series of trials, they were shown three toys. The experimenter took one toy and said to the child, "This is yours, this is for you." That toy was placed in front of the child. For a second toy, the experimenter said, "This is mine, this is for me." That toy was placed in front of the experimenter. (The order of these two assignments of objects was varied over trials.) A third toy was shown to the child and was placed on the table without being given to anyone.
Next, all three objects were moved to a tray in front of the child, who was asked which toy belonged to the experimenter and which toy belonged to the experimenter.
There were three versions of the sets of toys that were used in the study, and the results depended on the sets.
In one condition, each of the three toys was attractive and each toy was different. For example, the set might contain three different toy cars. In this case, even 2-year-olds were able to identify which car was theirs and which was the experimenters, though they were not quite as good at this as the 3-year-olds.
In another condition, all three toys were identical. In this case, the only way to know which toy belonged to which person was to keep track of where those toys had been on the table. In this case, the 2-year-olds had trouble with the task, but the 3-year olds did quite well identifying which toy belonged to which person.
In a third condition, two of the toys were attractive (toy animals, perhaps), and the third was boring (a Styrofoam block). The boring toy was assigned to the child. In this case, the 2-year-olds tended not to claim ownership of the boring toy, though they did know which interesting toy belonged to the experimenter. The 3-year olds correctly recognized which toy belonged to which person.
These results suggest that by 3-years of age, children know what belongs to them even if the objects are all identical and even if they really want something else.
Does this ownership matter?
To explore this question, the experimenters took advantage of something called the endowment effect. Danny Kahneman and his colleagues have found that people tend to like objects that they own better than objects that they do not own, even if they have been randomly assigned to those objects. For example, people who are given a coffee mug in an experiment value that mug more highly than people who are just shown the mug.
In a second study, children were assigned objects just as they were in the first experiment. In this case, though, the question they were asked was which object they liked the best. They were also asked which object the experimenter liked best.
The most interesting result in this study came from the condition in which all three toys were identical. In this case, both 2-year-olds and 3-year-olds tended to prefer the object that was assigned to them rather than either of the other two (identical) objects. Interestingly, even though 2-year-olds had difficulty identifying which object was theirs in this task, they still showed a preference for the one that had been given to them.
Putting this all together, then, children learn quickly that the ownership of an object is based on the history of that object. Of course, they get a lot of feedback about that as they grow up. Early on, we start to tell children which objects are theirs and which belong to other people. They learn that there are things they are allowed to do with objects that belong to them that they cannot do with objects that belong to someone else.
It is interesting, though, that even for young children this ownership also brings with it a preference. When a child owns an object, they tend to like it better than even identical objects that belong to someone else.