Does religion have an evolutionary role?

Kat Arney put this question to Ginny Smith...

Ginny - It's a difficult question to answer because humans are the only species we know of that has religion. So the question is - how, and or why, did we evolve religion? And we don't really know, but there are two ways that it could have happened. One is that religion evolved due to natural selection because it has a selective advantage. Those of our ancestors who became religious did better than those who didn't and so it was selected for. Another thing is is that it could be an evolutionary byproduct. It may be that we evolved something that was really useful, and then religion came along for the ride as a kind of byproduct of that thing that was usefull.

Kat - I mean I think there's an argument about it having some sort of social cohesion and a lot of religions have rules around hygiene, and eat this, don't do that. let's do this, let's go here.

Ginny - Yes. So that's one of the ideas that, if it did have a selective advantage, that could have been one. It seems like religions came along around the same time our ancestors were starting to live in bigger groups. When social cohesion would have been really important. They often involved watchful ancestor spirits - that kind of thing. People keeping an eye on what you're doing and, if you have that ever present person keeping an eye on you, there's this really big impetus to do the right thing, and if you're living in a big group that's really important.

Chris - Where do you think the observation from South Africa, last year, comes in Ginny - the Homo naledi findings where these primitive people (they may be 2 million years old), appeared to be burying their dead. To all intents and purposes these animals had a brain the size of an orange and we know that equivalently brained animals are not known to be Einstein. So, is it that there's some sort of primitive thing that evolves that you want to have respect for the dead, or whatever? David what do you think?

David - I mean religion in itself you can look at it from two perspectives. As the lady said earlier on, as human beings started to live in bigger communities and, obviously, there had to be some rules of control, let's just say. But I think also if we look at religion I think the concept - I mean this is maybe controversial - but once a certain intellect starts to be perceived, and the consciousness of death starts to appear, I think that religion has a role in that play as to ease the concept of death, I suppose you could say.

Ginny - Yes. That would kind of fit with the - it's a byproduct thing. That we became more intelligent because that was useful for making tools. We gained this ability to see cause and effect but then that meant we were looking for bigger causes and effects. We were looking for something more and perhaps put together things that maybe didn't go together and we saw a divine power and then, as you say, once you start to understand your own mortality, it's very comforting to have an idea of an afterlife and it does seem to be something that really pervasive all across human cultures, human religions. They all have this idea of the afterlife and what to do with your dead and I thinks that's probably right, it's got an element involved there.