Symbolic thought is the human ability to visualize shape and function and then to render those visions into a physical form (paintings. models, etc.) This ability is believed to have co-evolved with human language use as language is essentially using symbols to represent objects and ideas. Symbolic thought is especially important in the fields of art, engineering and architecture where it is necessary to first visualize desired results and then follow through on creating that image. For instance, if our ancient ancestors had not been able to visualize needed tools and weapons they would not have been able to create the items that were necessary for society to progress. Research has shown that children as young as 18 months are capable of symbolic thought.