I’ve written before about why religions exist. By no means an exhaustive essay, similar to this one.

Religions are persistent and pervasive throughout human civilizations. It always seemed strange that religions are so regional and cultural. Wherever you were born and in which culture you were born usually coincided with whatever religion you adopted. Why is that? Why wouldn’t people see other religions that appealed to their sense of spirituality more and disperse to other religions in an equilibrium like particles dispersing in water?

It makes more sense in the light of tribalism. The number one priority of an organism is to continue living. The second is to reproduce. Only one organism that we know of that is aware of its own mortality and that is the human. No human, from the tribal elite to the ostracized, wants to die, and fear of death is the strongest of all fears. All humans in the tribe want to believe they aren’t going to die and religion, along with the belief in an afterlife assuages that fear. It’s reassuring if others share your religious beliefs, and especially so if the tribal elite shares those beliefs. If the elites believe it, you should believe it!

Part of achieving acceptance and standing in the tribe is reassuring your tribesmen that they aren’t going to die, because our religion says we’ll live on in an afterlife. The elites want that, too. Once that’s established, it can be used to codify and enforce moral codes that enhance tribal harmony, unity and encourage a high-trust social hierarchy. Societies like this will tend to succeed. That success leads to selection for the genes that caused this behavior.

Tribal cohesion is essential for the tribe’s success. Though the property-based libertarian moral code is baked in to the human genome, people are still often subject to emotion overriding this instinct, creating conflict. Because people generally don’t grasp the philosophy behind moral codes, religions can be an effective way to enforce moral codes within a tribe. The tribe members won’t understand moral philosophy, bit they will understand that their all-powerful god will deny them the afterlife if they don’t behave. So, religions serve multiple purposes in helping the tribe to survive.

Pathological personalities, while they may try to manipulate the religious beliefs of their tribesmen for their own benefit, they will also be unlikely to abide by religious moral codes and be rejected by the tribe, resulting in their exile and probable death or by being directly killed by god-fearing tribesmen. Tribes in which pathological personalities were able to successfully manipulate the tribe through religious misdirection would have been less likely to survive.

This helps to explain the tribal nature of religion and why it’s so universal among humans. Like the tribal survival instinct itself, religion has become genetically selected for.