For every physical characteristic that is universal to a species, there must exist specific genes responsible for the emergence of that particular trait. The fact, for instance, that all humans have a nose in the middle of their face is not an accident but a direct consequence of our genetic make-up, our DNA.
This same principle applies not only to universal physical traits but to universal behaviors as well. The fact that all dogs bark, cats meow or beavers build dams suggests that they are genetically predisposed for such behaviors, that they are inherited instincts. Take a newborn kitten away from its mother and raise it by humans, it will still grow up to meow, supporting the notion that this is not a learned behavior but something inherited. As all behaviors are generated from an animal’s brain, this would further suggest that, in the case of cats, there must exist a specific series of neural connections—what we could informally refer to as the “meow” part of a cat’s brain—responsible for generating that particular instinct.
Within our own species, every human culture has communicated through a spoken language suggesting that our species' linguistic abilities constitute an inherent part of our natures, a genetically inherited trait. Similar to a cat’s meow, this would similarly suggest that there must exist specific regions in our brains that are responsible for generating our linguistic capabilities. With the aid of neuroscientific research, we know such linguistic sites exist in the human brain and include the Wernicke's area, Broca's area and angular gyrus. Damage incurred to any one of these sites will impede some aspect of our capacity to communicate or comprehend linguistically.
What if we were to apply this same principle to the fact that every known culture dating back to the dawn of our species has believed in some form of a spiritual reality? Wouldn't this suggest that human spirituality must therefore represent a genetically inherited trait? Furthermore, wouldn't this then also suggest that we must possess specific parts of our brain from which our "spiritual" instincts are generated? I informally refer to such neurophysiological sites as the "God" part of the brain, specific neural sites from which our spiritual beliefs are generated.
How else are we to explain the fact that all human cultures have maintained a belief in some form of a spiritual/transcendental realm; in a god or gods; in the concept of a soul as well as an afterlife; or the fact that every human culture has built houses of worship through which to pray to unseen forces? Wouldn't the universality with which such behaviors and beliefs are exhibited among our species suggest that we are genetically "hard-wired" this way? Just as all honeybees are compelled to construct hexagonally shaped hives, perhaps humans are compelled to believe in a spiritual realm...as a reflex, an instinct.
If what I'm suggesting is true, it would imply that God is not something that exists "out there," beyond and independent of us, but rather as the manifestation of the manner in which our brains are "wired" to perceive reality. And why would our species have evolved such a seemingly abstract cognitive trait? I propose this adaptation evolved in us to help us survive the debilitating existential anxiety that came with our species' unique awareness of death. Here lies the origin of humankind's spiritual function, an evolutionary adaptation—a coping mechanism, if you will—that compels our species to believe in gods, spirits/souls, afterlives, superstition and the paranormal--in essence, all forms of "magical thinking." It is through this predisposition to believe in the supernatural, that though we know we are one day going to die, we take comfort in that our "spirits" or "souls" will persist for all eternity.
"The 'God' Part of the Brain" offers a secular humanistic/atheistic alternative to our old religious paradigms. Herein lies a new way of perceiving ourselves, our places in the universe and ultimately what it means to be human—flawed and mortal—but with the hope of living meaningful and fulfilling existences despite the fact that there is no God, no soul nor any afterlife.