According to Piaget, a striking difference between infant and preschooler cognition is the ability to use symbolic thinking, which involves the use of words, gestures, pictures, or actions to represent ideas, things, or behaviors. Similar to motor skill development, the ability to symbolize occurs in gradual steps and is dependent on interactions with other persons and objects in the environment. As monumental as symbolic thought might be, Piaget referred to the cognitive development between ages 2 and 6 as preoperational thought. Due to the constraints of preoperational thought, preschoolers' first symbolic concepts are not as complete or as logical as are those of older children and adults; thus they are referred to as preconcepts. An illustration of a preconcept used by preschoolers is overgeneralization. Young children know, for example, that whoever walks on two legs, is tall (according to the standards of young children), and speaks in a deep voice belongs to a particular class of persons (Piaget & Inhelder, 1969). The English word they learn for this class of persons is usually Daddy; the Hindu term is Bapu, and the Xhosa (South African) word is Tata. So when young children use the terms Daddy Papal Bapul Tata, or other linguistic variations to refer to all men, they are demonstrating the ability to use preconcepts. The same classification ability is demonstrated when English-speaking preschoolers call dogs, cows, and horses, doggies. Besides calling all men by the term their culture uses for father and using one term to distinguish all large, four-legged animals, young children have difficulty in distinguishing specific members of a species from each other. This inability is evident in a young child who has seen a kitten down the street thinking another kitten seen in another place is the same one (Elkind, 1976).

Preschoolers' Egocentrism

It is the nature of young children to be egocentric in their thinking. To say that preschoolers' thinking is egocentric simply means that young children have an excessive reliance on their own point of view, coupled with a corresponding inability to be objective. By and large, young children tend to focus on one feature or perspective at a time. Their tendency to focus on one aspect of a situation to the exclusion of all others is called centration. Preschooler egocentrism shows up in young children's inability to share their toys, a fact that parents often fail to understand. Because parents frequently do not comprehend the limitations of young children's logic, they tend to scold them when they refuse to share their toys. The inability to consider two perspectives at once, however, means that very young children are unable to comprehend the concept of sharing. According to Piaget, the reluctance to share does not mean that young children are necessarily selfish. On the contrary, they frequently attempt to comfort others in distress. Their attempts to comfort another child or an adult, however, are likely to come in a distinctly egocentric form such as offering a toy or lollipop. These examples reflect the preschooler's lack of understanding about what might soothe another person as well their egocentric view that what is important to them is also valuable to others. The inability of preschoolers to consider two perspectives simultaneously can also be seen in their failure to conserve matter and volume. The inability to understand that the quantity of matter (such as clay) does not change when the shape changes, or that the volume of water remains the same if it is poured from a short squat glass to a tall narrow glass, is reflected in preschoolers' judgment (Piaget & Inhelder, 1969). Where that lack of understanding is likely to show up is if young children are given drinks in different-size containers. The young child is likely to complain that another child has more juice if the other child's glass is taller, even if the amount of juice is the same in both glasses.

What This Means for Professionals

Rather than expressing impatience with preschoolers when they do not share, parents might take their young children's perspective in the matter. Parents can be certain that each child has an identical toy or when noticing that two children are insisting on having the same toy might distract one of the children by offering that child an equally attractive toy. Because preschoolers lack the ability to conserve matter and liquid, parents need to be patient with them when they complain that they have less lemonade than the other children whose glasses are taller (even though they are narrower). Instead of providing a logical explanation to the prelogical preschooler regarding how the width of one glass compensates for the height of the other glass, it is better to take care that glasses chosen for their liquid refreshments are all the same height and width.