A suggestive analogy is to be seen in the case of the grayling moth, which prefers darker mates to those actually offered by its present species. For if human art can offer to a moth the supernormal sign stimulus to which it responds more eagerly than to the normal offerings of life, it can surely supply supernormal stimuli, also to the IRMs [Innate Releasing Mechanisms] of man and not only spontaneously, in dream and nightmare, but even more brilliantly in the contrived folktales, fairy tales, mythological landscapes, over- and underworlds, temples and cathedrals, pagodas and gardens, dragons, angels, gods, and guardians of popular and religious art. It is true, of course, that the culturally developed formulations of these wonders have required in many cases centuries, even milleniums, to complete. But it is true also . . . that there is a kind of support for the reception of such images in the deja vu of the partially self-shaped and self-shaping mind. In other words, whereas in the animal world the "isomorphs," or inherited stereotypes of the central nervous structure, which for the most part match the natural environment, may occasionally contain possibilities of response unmatched by nature, the world of man, which is now largely the product of our own artifice, represents to a considerable extent, at least an opposite order of dynamics; namely, those of a living nervous structure and controlled response systems fashioning its habitat, and not vice versa; but fashioning it not always consciously, by any means; indeed, for the most part, or at least for a considerable part, fashioning it impetuously, out of its own self-produced images of rage and fear.
Joseph Campbell, The Masks of God: Primitive Mythology