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Category Archives: Preschoolers

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).

Materials

  • 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

Procedure

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.

Reference:

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.

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Pick This, Not That (30-36 months)

**How children use rules to learn the meanings of new words**

 How can children learn new words so quickly?  Do they have some way to match new objects to new words that they hear and will they resist giving an object two names?  Many psychologists have studied what they call the “mutual exclusivity” bias where children learning new words avoid giving an object they already know another name and instead assign a new name to a novel object.  Below I describe one of the first studies to show this learning mechanism: Markman & Wachtel (1988).

Materials

  •  Six familiar objects, that is, objects that you know your child knows how to label. In the study they used: a banana, a plate, a cup, a spoon, etc.
  •  Six unfamiliar objects, that is, objects that you know your child does not know how to label.  In the study they used: a cherry pitter, a lemon wedgepress, tongs, an odd shaped container, etc.
  •  Six nonsense words.  Researchers use a variety of words that are novel to children to test out their theories of word learning.  For example, you can use:  fep, bleen, dorn, febbit, blick, and plog.

Procedure

Sit on the floor across from the child.  Tell the child, “I’m going to show you some things and ask you to pick some. Listen carefully and give the best answer you can.”  Place a pair of one familiar object and one unfamiliar object in front of the child.  Ask him to “Show me the X” using one of the nonsense words from your list and record which object your child picks.  Do not provide any feedback.  Continue this process with the next five pairs of familiar and unfamiliar objects, using a different nonsense word for each pair.

Notes & Observations

What did you observe? Did your child pick the novel object when you asked to see the “fep” or other novel word?  What do you think he would have done if you said “show me one”?

Research Findings & Extension

The researchers found that when asked to pick the object referred to by the nonsense word, children picked the unfamiliar object on almost 5 out of 6 trials.  This was more often than expected by chance; in contrast, they chose randomly in the condition where the researchers asked the children to “show me one.”  Thus, the children were not just gravitating toward the unfamiliar object; the presence of the novel word compelled them to pick the novel object.  The paper goes on to test many different variations, including how children attribute novel words to parts of objects.  Others have looked at bilingual children and how they suspend this bias, since they, of course, need to assign two words to each object, one in each language.

Reference:

Markman, E.M. & Wachtel, G.F. (1988).  Children’s use of mutual exclusivity to constrain the meanings of words.  Cognitive Psychology, 20, 121-157.

A Trusted Agent (3 years)

**How children strongly trust what people tell them**

Can children resist the urge to trust what adults tell them?  When can they suspend belief in others and change their behavior accordingly?  Jaswal et al. (2010) examined whether children have a strong inclination to believe what others tell them.  In the study, the researchers had children participate in different conditions which, when compared, tested their hypotheses.  Below, I’ll describe the mechanisms of the “testimony” condition which shows the strong effect of children’s trust in spoken testimony when searching for something desirable: a sticker.

Materials

  •  8 stickers
  •  Two plastic cups of different colors (e.g., red and blue) that the stickers can be hidden beneath
  •  A tray where the cups can be placed upside-down
  •  A piece of cardboard large enough to conceal your hands while hiding stickers under the cups but not so large that your shoulders and face are concealed
  •  A confederate (e.g., a family friend) who can provide the testimony

Procedure

Ask the confederate to sit at a table across from the child.  Start by explaining to the child that she’s going to play a game where she tries to find a sticker hidden under the cups.  If the child finds the sticker in the first cup she looks under, she gets to keep it – otherwise the confederate does.  He also tells the child, “I’m going to try to get as many stickers as I can! How about you?”

Start by placing the two cups on opposite ends of the tray and then position the cardboard screen to hide the confederate’s hands as he places the first sticker under one of the cups behind it.  He then lifts the screen and says that the sticker is hidden in the cup opposite to where it’s actually hidden; if it’s under the blue cup, he says:  “it’s in the red cup.” Next, push the tray toward the child and allow her to search under one cup. If she chooses the cup that was indicated, the incorrect cup, she will not find the sticker and the confederate can show her where it is and then keep it. If she chooses the correct cup, she can keep the sticker she finds.

This game continues for 8 trials; mix up whether the sticker is actually on the right or left so that it’s balanced. You can keep track of which cup the child chooses each time. Don’t worry, the child can have all of the stickers at the end (and even one occasionally during the game if he’s getting frustrated!).

Notes & Observations

What did you observe? Did your child search under the indicated cup the first time?  What about the subsequent trials?  Did he come to a realization about your “trickiness” and change course?

Research Findings & Extension

The researchers found that, naturally, all children looked under the cup that was indicated (“it’s in the red cup”) on the first trial.  Surprisingly though, children did not quickly realize that they should not trust what the experimenter said – many children did not find a single sticker over 8 trials!  In the study, a second condition was used called the “arrow” condition where the adult indicated which cup held the sticker by placing an arrow on it (children were trained to use this as a cue) but did not say anything.  In contrast, in that condition, children quickly realized that they should not trust the arrow’s location and found many more stickers.  The researchers argued that children’s belief in verbal testimony is so entrenched that it is difficult for them to inhibit responding to it (whereas they are not accustomed to trusting the arrow).  This sort of trust in the adults around them would be adaptive for infants and children since they have no other source for helpful information and would become stronger over time as it’s reinforced. By age 4, children do not show this same persistent trust.

Reference:

Jaswal, V.K., Croft, A.C., Setia, A.R., & Cole, C.A. (2010). Young children have a specific, highly robust bias to trust testimony. Psychological Science, 21, 1541-1547.