Art making is central to the practice of art therapy. Unfortunately an understanding of art and its use in art therapy is often unclear and divided along theoretical lines. A dependable, more precise understanding of what art is within the context of art therapy may prove to greatly increase credibility in the field. I propose that one of the best ways to build a solid theoretical understanding of art is to examine it from an evolutionary perspective. Within this framework, art is understood as the behavioural tendency to make special, a concept developed by Ellen Dissanayake.  Current literature on the biological, developmental, cognitive and environmental factors involved in the evolution of a capacity to make special are examined. Two theories regarding the adaptive function of making special- Kathryn Coe’s ancestress hypothesis and Denis Dutton and Geoffrey Miller’s sexual selection hypotheses- are also explored. Art making is demonstrated to have evolved from making special and is established as a biologically complex, universal and evolutionary beneficial behaviour.  From this perspective, an understanding of making special may help to inform, fortify and unify the theoretical basis of the function of art making in art therapy.