Robin Marantz Henig in The New York Times Magazine, a look at evolutionary explanations of religious belief.
Some cognitive scientists think of brain functioning in terms of modules, a series of interconnected machines, each one responsible for a particular mental trick. They do not tend to talk about a God module per se; they usually consider belief in God a consequence of other mental modules.
Religion, in this view, is “a family of cognitive phenomena that involves the extraordinary use of everyday cognitive processes,” Atran wrote in “In Gods We Trust.” “Religions do not exist apart from the individual minds that constitute them and the environments that constrain them, any more than biological species and varieties exist independently of the individual organisms that compose them and the environments that conform them.”
At around the time “In Gods We Trust” appeared five years ago, a handful of other scientists — Pascal Boyer, now at Washington University; Justin Barrett, now at Oxford; Paul Bloom at Yale — were addressing these same questions. In synchrony they were moving toward the byproduct theory.
Darwinians who study physical evolution distinguish between traits that are themselves adaptive, like having blood cells that can transport oxygen, and traits that are byproducts of adaptations, like the redness of blood. There is no survival advantage to blood’s being red instead of turquoise; it is just a byproduct of the trait that is adaptive, having blood that contains hemoglobin.
Something similar explains aspects of brain evolution, too, say the byproduct theorists. Which brings us to the idea of the spandrel.
Stephen Jay Gould, the famed evolutionary biologist at Harvard who died in 2002, and his colleague Richard Lewontin proposed “spandrel” to describe a trait that has no adaptive value of its own. They borrowed the term from architecture, where it originally referred to the V-shaped structure formed between two rounded arches. The structure is not there for any purpose; it is there because that is what happens when arches align.
In architecture, a spandrel can be neutral or it can be made functional. Building a staircase, for instance, creates a space underneath that is innocuous, just a blank sort of triangle. But if you put a closet there, the under-stairs space takes on a function, unrelated to the staircase’s but useful nonetheless. Either way, functional or nonfunctional, the space under the stairs is a spandrel, an unintended byproduct.
“Natural selection made the human brain big,” Gould wrote, “but most of our mental properties and potentials may be spandrels — that is, nonadaptive side consequences of building a device with such structural complexity.”
An interesting idea at the end of the article:
What can be made of atheists, then? If the evolutionary view of religion is true, they have to work hard at being atheists, to resist slipping into intrinsic habits of mind that make it easier to believe than not to believe. Atran says he faces an emotional and intellectual struggle to live without God in a nonatheist world, and he suspects that is where his little superstitions come from, his passing thought about crossing his fingers during turbulence or knocking on wood just in case. It is like an atavistic theism erupting when his guard is down. The comforts and consolations of belief are alluring even to him, he says, and probably will become more so as he gets closer to the end of his life.