It's easy to chart your child's physical development -- as a parent, you know when your child goes from crawling to walking, or from bumping her head on the counter to being able to raid the cookie jar. Mental development is a little more elusive, but identifying key stages of cognitive development, including the development of symbolic thought, helps demystify the process.
As the term implies, symbolic thought refers to the ability to represent people, objects and events -- even those that are not present -- by using internal symbols or images. In his book "The Psychology of Intelligence," development psychologist Jean Piaget defines symbolic thought as the representation of reality through the use of abstract concepts.
You'll often see signs of symbolic thought in your child's play as she approaches preschool age. When one object stands in for another, that's symbolic thought in action. For instance, a stick becomes a sword or a bath towel becomes a superhero's cape. Symbolic thought is not limited to objects, however. As kids develop the ability to think symbolically, they "play pretend," imagining themselves as other people, or even animals or fantastical objects.
Symbolic thought also manifests in more concrete ways. Children develop some form of symbolic thought as early as 18 months, when they use signifiers -- such as sounds or gestures -- to refer to concrete objects or people. Later, these signifiers might refer to concepts or non-present objects, such as a parent or the idea of family. Still later, as children learn to write words, draw pictures, act in plays or even sing songs, they are expressing their ability to think symbolically. In advanced stages, symbolic thought allows people to manipulate intangible objects, which comes into play when solving a mathematical equation, for instance.
In addition to helping children communicate, symbolic thought is a key element in expanding a child's imaginative capabilities. Fostering symbolic thought development by encouraging self-expression and make-believe scenarios also helps children develop their social skills and creative skills. As symbolic thought attaches immaterial notions to concrete things and events, it allows children to associate a certain event, place or object with abstract ideas, such as feelings. This helps form a person's worldview, and in later life, allows children to make hypothetical judgments, determine relative values and express emotions in a complex fashion.