"Metaphor works, most obviously, when we recognize a similarity between two different things. It is a matter of "pattern recognition," which may be more important in the working of the brain than logic. "Early human thought proceeded by metaphor," according to Nobel Prize-winning neurobiologist Gerald Edelman. And this imprecise sort of figurative thinking is "a major source of imagination and creativity in adult life.""
"He [Geary] is impressed with research demonstrating that, in laboratory experiments, people exposed to certain metaphors were more open to certain behaviors, an effect called "priming." "Subjects primed with words relating to cooperation," Mr. Geary says, "cooperated more on test tasks than those who were not primed.""
Now here is something about metaphors from the Wikipedia page on Joseph Campbell:
"Thou Art That: Transforming Religious Metaphor (2001) — An exploration of the myths and symbols of the Judeo-Christian tradition
The first title in the series, this book compiled many of Campbell's ideas on the mythic underpinnings of the Judeo-Christian tradition. In it he writes, "Mythology is often thought of as other people's religions, and religion can be defined as mis-interpreted mythology." In other words, Campbell did not read religious symbols literally as historical facts, but instead saw them as symbols or as metaphors for greater philosophical ideas. Campbell had previously discussed this idea with Bill Moyers in The Power of Myth:
CAMPBELL: That would be a mistake in the reading of the symbol. That is reading the words in terms of prose instead of in terms of poetry, reading the metaphor in terms of the denotation instead of the connotation.
MOYERS: And poetry gets to the unseen reality.
CAMPBELL: That which is beyond even the concept of reality, that which transcends all thought. The myth puts you there all the time, gives you a line to connect with that mystery which you are."