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Tag Archives: cognitive development

Think twice (19-22 months)

**How children update their mental representation of an object**

Many studies have looked at how children learn about the world from what they observe, but how do children come to learn from what others tell them?  Going one step further, when does the ability to learn new information about objects that aren’t even present emerge? This would involve bringing to mind a mental representation of the object and incorporating the new information into your understanding of, for example, what it looks like.  Researchers examined this question in a study that looked at the emergence of young children’s ability to update their mental representations of an object based on information given by an adult when the object was in another room (Ganea et al. 2007).   The two ages examined, 19 and 22 months, span the time when this ability comes online.


  • Two identical stuffed animals (e.g., two green frogs)
  • One different stuffed animal (e.g., one pink pig) to be a distractor
  • One bucket of water
  • Three aluminum trays
  • A confederate


Start by showing the child the three stuffed animals and introduce one of the two identical ones with a proper name (e.g., Lucy). Show the child the other identical toy but do not name it and then set it aside. Finally introduce the different toy as a friend and then allow the child a few minutes to play with the named toy and the different, distractor toy.  Check that the child learned the name for the target animal (e.g., by putting them both down and asking the child to “get Lucy”).

Then put the three animals away (e.g., in a basket) and leave the room with the child.  While looking at a book with the child, the confederate should enter carrying a bucket of water and say that she planned to wash something (e.g., a table) in the other room (where the toys are).  After 2 minutes, the confederate should return and say: “I’m so sorry! I was washing the table, and I spilled water all over Lucy. Lucy is wet now! She’s covered with water” (Ganea et al., p. 736).  You can then say to the child, “Oh no, did you hear that? Lucy got wet! She’s all covered in water. Do you want to go see Lucy? Let’s go see Lucy!”

In the test phase, when the child re-enters the first room, she will see the three stuffed animals on the three trays.  One of the identical toys and the different, distractor toy should be wet.  The trays should be arranged such that the different wet toy is on its tray between the trays with the wet target toy and the dry identical toy.  Ask the child to show the target animal: “Which one is Lucy? Show me Lucy.”

Notes & Observations

What did you observe? Which toy did your child choose? The child should choose the wet target toy if she has updated her mental representation from the information given by the confederate. However, she might choose the dry identical toy if she had not updated her representation of “Lucy” or the different wet toy if she was just interested in a wet toy.

Research Findings & Extension

The researchers found that 22-month-olds reliably chose the wet target animal greater than chance whereas 19-month-old children seemed to choose randomly between the wet and dry versions of the stuffed animal. Thus, children’s ability to update a mental representation of an object with new information that they hear about but don’t see happen emerges around this age.  This capability opens the doors for learning all sorts of information indirectly and remembering it going forward.


Ganea, P. A., Shutts, K., Spelke, E., & DeLoache, J, S. (2007). Thinking of things unseen: Infants’ use of language to update object representations. Psychological Science, 18(8), 734-739.


Yours, Mine, and Ours (2-3 years)

**How children develop an understanding of ownership**

Anecdotally, we have all seen that children can be possessive with their objects.  But knowledge of who owns an object is not obvious from looking at it, so how and when do children come to know that something belongs to them versus someone else? How do they keep track of an object’s history and discriminate their object from other similar objects? Researchers have started to look at this question with clever experiments with 2 and 3 year olds that disentangle which factors children pay attention to when determining ownership (Gelman, Manczak & Noles, 2012).


  • Set 1: a set of three different objects, but from the same category (e.g., three different looking car, animal, or food toys)
  • Set 2: a set of three objects that are identical (e.g., three of the same toy cars, animals, or foods)
  • Set 3: a set of three objects, two of which are from the same category (e.g., two different cars) and one object which is plain and undesirable (e.g, a piece of Styrofoam or cardboard)
  • A tray to place the three objects on during the question phase


Sit at a table with the child with the objects out of view.

Trial 1:  Start with the objects from Set 1, which you will take out one at a time. For this set, it does not matter which of the three objects are assigned to you or the child. For the labeling phase, bring out the first object and say “This is yours; this is for [child’s name],” and put it in front of the child.  Then, bring out the second object, show it to the child, and say, “This is mine; this is for [your name],” and place it in front of yourself.  Finally, bring out the third object, hold it up to show the child, and say, “See this; look at this,” and then place it on the table equidistant from the other two objects.  For the question phase, take the three objects and place them on a tray in the order that they were first presented as the child watches.  Then ask: (a) “Which one is yours?” and (b) “Which one is mine?” and note whether the child picks the correct objects for the two questions.

Trial 2:  Follow the above procedure with the objects from Set 2 and note the responses. For this set, it does not matter which of the three objects are assigned to you or the child since they are identical.

Trial 3: Follow the above procedure with the objects from Set 3 and note the responses. For this set, be sure to assign the plain object to the child.

Notes & Observations

What did you observe? Did your child keep track of which object he was assigned for each set of objects?  Were any of the sets easier or harder?

Research Findings & Extension

The results of the study were different based on the age of the child and the make-up of the set of objects.  Both 2 and 3 year olds were good at the task with varied sets of objects like Set 1, meaning that they kept track of them and correctly answered the questions about which object was assigned to themselves and the researcher.  The set of identical object was more difficult for the 2 year olds but the 3 years did well on this task, meaning that they tracked their object “through space and time” using the information they were told – even though all three objects looked exactly the same. Although the researchers didn’t try this, it would be fun to see just how good children are at tracking their object visually, Three-Card Monte style J Finally, the set where the child gets the plain object was hardest for the 2 year olds who actually did a better job of keeping track of the researcher’s more interesting object than their own. The researchers also looked at a phenomenon called the “endowment effect” where people tend to like something more just because they own it – there’s a lot more to study about ownership, but it’s clearly an understanding that takes root early on.


Gelman, S., Manczak, E., & Noles, N. (2012). The nonobvious basis of ownership: Preschool children trace the history and value of owned objects.  Child Development, 83, 1731-1747.