That is a difficult concept to grasp, particularly when you are a 3-year-old. But psychologists have discovered something that helps – symbols.
Researchers investigating how self-control develops in children found that abstract symbols can lead the youngsters toward a more optimal decision than when they have to make a choice with tangible objects such as candy.
This was demonstrated when the researchers gave 3-year-olds the choice of a tray with two pieces of candy or one with five. Even when told that the tray they picked would be given away, most of the youngsters still picked the tray with the most candies.
However, when abstract symbols, such as dots or animal pictures were used to represent the candy, many of the 3-year-olds caught on and chose the symbol representing the smaller amount of candy, leading to the larger reward.
"Many 3-year-olds are compelled to point to larger rewards even though in this game that means they will get a smaller reward. When you remove the real reward and substitute it with symbols, it enables children to control their response," said Stephanie Carlson, a University of Washington associate professor of psychology and lead author of a new study appearing in the current issue of the journal Psychological Science.
"When children get stuck on a problem, using symbols can help them solve it. For example, if you are trying to get kids to wait for a marshmallow as a reward it is helpful to get them to think about the reward in a different way – such as thinking of the marshmallow as a fluffy cloud to help them delay gratification. Many parents, however, tend to do the opposite. They say, 'you can't have it now, but just think about how good it will taste when you can.' This increases the temptation instead of shifting their attention," she said.
Carlson, who is studying executive functioning, or how children develop the ability to control their thoughts and actions, set up two experiments.
The first showed that this ability is directly related to age and verbal ability. In the experiment, 101 typically developing 3- and 4-year-olds had to make the choice between the trays containing either smaller or larger amounts of candy (jellybeans or chocolate chips). An experimenter explained the rules, and showed each child that when they pointed to a tray the candy would go to a toy monkey and the child would get the contents on the other tray. Each child was given 16 test trials, with candy being replaced on the trays after each trial.
Four-year-olds significantly outperformed the 3-year-olds, although some of the 3-year-olds with high verbal ability scored well. The 3-year-olds did not improve over the course of the trials while 4-year-olds showed significant learning.
"Three-year-olds tended to be inflexible and didn't seem to improve with the feedback of seeing the toy monkey getting more treats," said Carlson. "But 4-year-olds changed strategies and appeared to learn from feedback without any explicit instruction."
In the second experiment, the researchers tested 128 typically developing 3-year-olds. The children were randomly assigned to one of four conditions – real treats, rocks, dots and one called mouse vs. elephant. In this experiment, two boxes with drawers containing two or five candies replaced the trays. In the first two conditions, a number of the candy or rocks corresponding to candy inside the drawers were placed on top of the boxes. In the dot condition pictures with a small or large number of dots were placed atop the boxes. In the mouse vs. elephant condition pictures of those animals were placed on the boxes and the children also were shown a stuffed toy mouse and elephant and told they had a small or large stomach that could hold a few or a lot of candies. In each case the researchers made sure the children understood that what was on top of each box corresponded to the two or five candies inside the drawers.
Then, as in the first experiment, the children were told to pick one of the two boxes, with candies inside the one they chose going to a toy monkey. Each child was given 16 trials.
There were significant performance differences depending on what was on top of the boxes. With the candies and the rocks, most of the children continued to pick the boxes with the larger amounts on top, just as the 3-year-olds in the first experiment did. But in the dots and mouse vs. elephant conditions, the children picked the boxes representing the smaller amount of candy significantly more often. And their performance was strongest in the most abstract conditions, mouse vs. elephant.
Carlson said the substitution of the real reward with symbols allowed the children to control their responses. Faced with the rock choice they "were compelled to pick the large number because the rocks had a one-to-one correspondence with the real treat." She said with the dots there was no resemblance to the treats, just lots or less dots, and amounts were totally eliminated in the choice between the mouse and elephant. The 3-year-olds performance on the mouse vs. elephant choice matched the performance of the 4-year-olds in the first experiment.
There were no differences in the performance by boys and girls in the two experiments.
Carlson said a big jump in children's self-control typically occurs between 3 and 4, along with other major related developmental changes such as the ability to understand another person's perspective and to engage in elaborate pretend play.
Co-authors of the paper were Angela Davis, a UW psychology doctoral student, and Jamie Leach, a former UW psychology undergraduate student who is now a doctoral student at Stanford University. The National Institute of Child Health and Human Development funded the study.
For more information, contact Carlson at (206) 543-5688 or carlsons@u.washington.edu
Journal
Psychological Science