"Many kinds of art are [designed] to induce a buildup and release of psychological tension, mimicking other forms of pleasure. And a work of art is often embedded in a social happening in which the emotions are evoked in many members of a community at the same time, which can multiply the pleasure and grant a sense of solidarity.
"Some reasearchers. . .believe that art is an evolutionary adaptation like the emotion of fear or the ability to see in depth. Others, such as myself, believe that art (other than narrative) is a by-product of three other adaptations: the hunger for status, the aesthetic pleasure of experiencing. . .and the ability to design artifacts to achieve desired ends."
from: "The Blank Slate: the Modern Denial of Human Nature" by Steven Pinker
from Chapter 20 'The Arts' pgs 401 - 420