When my younger daughter was around 4 years old, we had an interesting conversation about her favorite cup. As in most households with multiple kids, we have an array of plastic cups of all shapes and sizes. Her favorite cup was a tall, thin cup with My Little Pony on it. I had always assumed she chose that cup because of the design on it, but one day I asked her why it was her favorite and she responded, “Because I get more.” After a few more rounds of questions, I figured out that because the cup was tall and thin, the amount of liquid in it looked like more compared to our other shorter and wider cups.
My daughter’s misconception of how much juice she was getting in her cup demonstrates the concept of conservation, an important milestone in children’s cognitive development. The conservation concept is central to developmental psychologist and philosopher, Jean Piaget’s stages of development. Children, typically starting around ages 6 – 7 years begin to understand conservation and become aware that merely changing the appearance or arrangement of objects does not change their key properties such as quantity.
Penny Party: Conservation Task
Piaget’s most famous conservation task involves pouring liquid (usually colored so it is easier to see) from one container to another that is a different shape. If children can conserve liquid, then they understand that the amount of liquid has not changed even though the appearance has changed. Here I describe another conservation task that is not as messy.
- Arrange 10 pennies into 2 equal rows so that one row is directly above the other row on a table.
- Point to one row and tell the child that will be his row of pennies and point to the other row and tell the child that will be your row of pennies.
- Ask the child to count each row, along with you.
- Then ask him, “Who has more pennies? Do you have more, do I have more, or do we have the same?”
- The child should confirm that you both have the same number of pennies.
- Rearrange your pile of pennies, so that your pile is different than your child’s. For example, spread out your row of pennies so your line is longer than the child’s row of pennies.
- Then ask, “Who has more pennies? Do you have more, do I have more, or do we have the same?”
A child who understands number conservation will respond, “We have the same.” Children around 7 years old or older will begin to understand this concept, but to reiterate, this task is used to benchmark growth, rather than measure success.The developmental “games” that I have described in this series of blog posts are just the tip of the iceberg in discovering amazing capabilities in young children. You could think of them as windows to your child’s creative capacity as they develop new and different ways of thinking about the world. Sometimes their view is more colorful and imaginative than ours! If you are interested in learning more about classic developmental phenomena, I highly recommend reading The Scientist in the Crib by Alison Gopnik, et al. and Einstein Never Used Flash Cards by Kathy Hirsch-Pasek and Roberta Golinkoff. Both books offer many more suggestions for fun games to play with your kids to learn how they learn.
