Art is innate to humans and developed alongside early tool making and speech. Pictorial symbols were also used for many early written languages such as Egyptian iconography and are still the basis of many languages. In Western culture written language is phonetic, that is based on sounds of spoken language. Verbal language is now the dominant language in many cultures, including Western culture.
Because verbal language is the dominant means of expression, it also more easily re-truamatises causing extreme fear and anxiety reactions of PTSD (Post Traumatic Stress Disorder). Expressing emotions through art uses a less familiar or alternative visual language which can enable a person dealing with trauma to reflect on experiences in a different way. In the controlled and safe space of art therapy this can be a way to assimilate traumatic memories without causing extreme stress reactions of PTSD that words, speech and thoughts more easily set off.