Religious Software in the Human Brain

The human brain has a desire to understand and explain things. This is the major component of evolved human intelligence. If you have brain experiences mentioned above—a sense of disembodiment; a conviction that everything is caused by an agent; sexual euphoria; and visions of the tunnel—you will also have the compulsion to explain them. Here is an empty space just waiting for memes to walk in. One meme told people that there must be something beyond death. Another meme told them that there must be spiritual beings causing everything from the wind to the rising and setting of the sun. Another meme told them that their experiences of disembodiment and the tunnel were actual observations of a spiritual realm. Put these together, and you have a primordial religion. The only alternative, to a prehistoric person, is to ignore the whole thing. The most successful people were those who figured things out, not those who ignored things. Even if the resulting beliefs were incorrect, so long as they enhanced the survival and reproduction of the believers, natural and sexual selection would favor them.

Human creativity is irrepressible, and it was inevitable that humans would couch their explanations of spiritual experiences in terms of mythological stories that addressed each of the brain phenomena, and that they would develop practices that enhanced the experiences. The stories had gods who made things happen. Religious practices were sometimes accompanied by hallucinogenic drugs, which tapped into the sense of disembodiment. Religion fed on sexual feelings in two ways: adherents experienced sexual feelings both about their deities and about charismatic religious leaders. Religion made us eager to follow charismatic leaders who claimed to have a connection with the gods. We humans had a desire to understand these overwhelming experiences—what young person has not tried to express the overwhelming sense of being in love?—and religious memes satisfied this desire.

The earliest religions may have been like the theology of Adam and Eve, as depicted in the early chapters of Genesis. They seemed to have no theology except that they knew there was a godlike being who walked around in the garden in the cool of the evening. Deep in the Cro-Magnon caves such as Lascaux and Altamira and Chauvet, people seeking religious experiences made lots of marks on the walls, and touched the walls, painting silhouettes of their hands. According to anthropologist David Lewis-Williams, they thought they were making contact with the spirit realm. It may have taken thousands of more years before complex mythologies and systems of theology developed.

This essay is part of my recently published book Life of Earth: Portrait of a Beautiful, Middle-Aged, Stressed-Out World, from Prometheus Books.