Piaget and Human Development
The famous developmental psychologist, Jean Piaget, proposed four distinct stages of human cognitive development. Based on his observations and research, he determined that each of these four stages of development was signified by the achievement of specific milestones.
The concrete operational stage is the third stage. According to Piaget, most children will enter this stage sometime around the age of seven and complete it sometime prior to age eleven. There are many factors at play in terms of the speed at which a child develops, so some children will reach this stage earlier than seven and exit it after eleven.
The Concrete Operational Stage
As the name implies, the concrete operational stage of development can be defined as the stage of cognitive development in which a child is capable of performing a variety of mental operations and thoughts using concrete concepts. More specifically, children are able to understand that just because an object changes shape or is divided into pieces, the object still retains certain important characteristics, such as mass or volume. Let's look at a couple of examples to help you better understand the definition.
Conservation Task Examples
Orange Juice
As mentioned, Piaget's developmental stages are associated with the achievement of specific milestones. The ability to master the conservation task is the classic milestone achievement of a child who has entered the concrete operational stage. Here is an example of the conservation task:
Start with two drinking glasses, which both hold eight ounces of fluid. Place them on a table in front of a child. Let's say that one of the glasses is three inches tall and the other one is six inches tall. Naturally, the glasses look very different from one another even though they are able to hold the same amount of fluid.
Next, fill the shorter glass to the brim with orange juice and then pour the juice from the shorter glass into the taller glass. The child is then asked which glass can hold more juice, the tall glass or the short glass. Any response other than 'they hold the same amount of orange juice' is incorrect and thus demonstrates a lack of concrete operational thought.
The child who recognizes that even though the shape of the orange juice has changed its volume remains consistent has mastered the conservation task. He has demonstrated the ability to mentally manipulate the orange juice and recognize that even though it looks different, it is the same amount.
Legos
Here's another example. The next time you are playing with a child and have some Legos handy, build a tower that is two feet wide by two feet tall. Using normal-sized Legos, that will probably take quite a few pieces to accomplish. Now, take the tower apart and spread all of those pieces across the floor. Ask the child whether there were more Legos in the tower or more scattered across the floor.