I think the beginnings of religion in pre-civilized societies seem quite natural if you put yourself in their places. Their environment consisted of things that behave predictably, like a rock or spear flying through the air, or things that sit there and do nothing, and things that behave unpredictably, like their fellow human beings, animals (more or less), the weather, volcanoes, etc. As it happens, if you try to imagine what other people are thinking, or what they will think if you say or do this or that, that might just be the one area where people, or maybe not oneself, but the wise people in the group might achieve some mastery. The weather -- well, we're still working on that. If is in our nature, when we have mastery in one area and none in another, to hope to make find some analogies from the area we somewhat understand and apply them in the more mysterious area.
So, in these societies you have people explaining every unpredictable thing, and convincing themselves they're actually understanding something about them --- things like weather, disease, floods, droughts, etc, in terms of the volition of some sentient being visible or invisible. Religion goes through all sorts of transformations partly as a result of how the society evolves, and some people discover it is a way to get some control over others by claiming to be more knowledgeable about the mysterious things.
It's really only in the last few hundred years that understanding of things in mechanistic terms finally accumulated enough to give (some) people confidence that maybe that was really the dominant paradigm, rather than the gods, witches, ghosts and other magical beings paradigm, and religion has millennia of entrenchment and institution building, and has come up with such ingenious lock-in clauses as "God will hate you and send you to hell if you don't believe -- believing certain things is labelled virtuous. The idea of trusting institutions of knowledge accumulation by experimentation, and choosing what to believe on the basis of "rational" procedures is still pretty new, and few people have gotten the hang of it. With most people, if they look to science very much for explanations, they are passively accepting what they were taught to do, and they're very succeptable to falling into a belief/social system that makes them feel good in some way.
Yeah, that's one common theory for the start of religious belief; basically, that we evolved a natural ability to both try and predict the future, and to predict what other people would do, and that religious thought and religious belief was a side effect of that, especially for dealing with unusual events that weren't obviously predictable based on what people knew at the time. That's quite possible.
What Eliezer was talking about is an entirely different theory; the theory that religious belief (or some genetic predisposition to religious belief) was ac...
Followup to: Rational vs. Scientific Ev-Psych, The Tragedy of Group Selectionism, Evolving to Extinction
Perhaps the real reason that evolutionary "just-so stories" got a bad name is that so many attempted stories are prima facie absurdities to serious students of the field.
As an example, consider a hypothesis I've heard a few times (though I didn't manage to dig up an example). The one says: Where does religion come from? It appears to be a human universal, and to have its own emotion backing it - the emotion of religious faith. Religion often involves costly sacrifices, even in hunter-gatherer tribes - why does it persist? What selection pressure could there possibly be for religion?
So, the one concludes, religion must have evolved because it bound tribes closer together, and enabled them to defeat other tribes that didn't have religion.
This, of course, is a group selection argument - an individual sacrifice for a group benefit - and see the referenced posts if you're not familiar with the math, simulations, and observations which show that group selection arguments are extremely difficult to make work. For example, a 3% individual fitness sacrifice which doubles the fitness of the tribe will fail to rise to universality, even under unrealistically liberal assumptions, if the tribe size is as large as fifty. Tribes would need to have no more than 5 members if the individual fitness cost were 10%. You can see at a glance from the sex ratio in human births that, in humans, individual selection pressures overwhelmingly dominate group selection pressures. This is an example of what I mean by prima facie absurdity.
So why religion, then?
Well, it might just be a side effect of our ability to do things like model other minds, which enables us to conceive of disembodied minds. Faith, as an emotion, might just be co-opted hope.
But if faith is a true religious adaptation, I don't see why it's even puzzling what the selection pressure could have been.
Heretics were routinely burned alive just a few centuries ago. Or stoned to death, or executed by whatever method local fashion demands. Questioning the local gods is the notional crime for which Socrates was made to drink hemlock.
Conversely, Huckabee just won Iowa's nomination for tribal-chieftain.
Why would you need to go anywhere near the accursèd territory of group selectionism in order to provide an evolutionary explanation for religious faith? Aren't the individual selection pressures obvious?
I don't know whether to suppose that (1) people are mapping the question onto the "clash of civilizations" issue in current affairs, (2) people want to make religion out to have some kind of nicey-nice group benefit (though exterminating other tribes isn't very nice), or (3) when people get evolutionary hypotheses wrong, they just naturally tend to get it wrong by postulating group selection.
But the problem with this hypothesis is not that it's "unscientific" because no replicable experiment was proposed to test it. The problem is that the hypothesis is, as a matter of prior probability, almost certainly wrong. If you did propose a valid experiment to test it, I would expect it to turn up negative.