The importance of evolved psychology is illuminated by perhaps the most important belief system of all: religion. Although the specifics vary widely, religious belief per se is remarkably similar across the board. Most religions feature a familiar cast of characters: supernatural agents, life after death, moral directives and answers to existential questions. Why do so many people believe such things so effortlessly?
According to the cognitive by-product theory of religion, their intuitive rightness springs from basic features of human cognition that evolved for other reasons. In particular, we tend to assume that agents cause events. A rustle in the undergrowth could be a predator or it could just be the wind, but it pays to err on the side of caution; our ancestors who assumed agency would have survived longer and had more offspring. Likewise, our psychology has evolved to seek out patterns because this was a useful survival strategy. During the dry season, for example, animals are likely to congregate by a water hole, so that’s where you should go hunting. Again, it pays for this system to be overactive.
This potent combination of hypersensitive “agenticity” and “patternicity” has produced a human brain that is primed to see agency and purpose everywhere. And agency and purpose are two of religion’s most important features – particularly the idea of an omnipotent but invisible agent that makes things happen and gives meaning to otherwise random events. In this way, humans are naturally receptive to religious claims, and when we first encounter them – typically as children – we unquestioningly accept them. There is a “feeling of rightness” about them that originates deep in our cognitive architecture.