What is art for

Dissanayake: Art has its roots in human nature

I can't do a better job of summarizing the book's thesis than Publishers Weekly did: "Dissanayake argues that art was central to human evolutionary adaptation and that the aesthetic faculty is a basic psychological component of every human being. In her view, art is intimately linked to the origins of religious practices and to ceremonies of birth, death, transition and transcendence."

Sample passage from Dissanayake:

In society after society we find practices that indicate the esteem given to the opposite of spontaneous and "natural" behavior or appearance. Aristocracies all over the world distinguish themselves by public signs of self-control, complex systems of etiquette, and other unnatural elaborations of behavior and speech...
Even in traditional societies without strict social hierarchies or classes, the distinction between human control and natural disorder is nevertheless made. The African Basongye distinguish between "music," which consists of sounds that are human, organized, and patterned, and "noise," which is nonhuman sound.