And the real question is why. What evolutionary purpose has this tendency, whose existence, even among the most rational of us, suggests that the search for transcendence may be hard-wired into human beings?
I would need some persuading that religious belief is a specific adaption; i.e. that we have evolved the tendency to believe in the same sense that we have evolved opposable thumbs.
This kind of argument is discussed at more length in that article you linked to, but my version of it would run something like this:
Let’s assume that a need to explain and understand things is hard-wired into human beings by evolution. We know so little, really, about how the mind works, that even that assumption is arguable, but it’s probably less of a leap than asssuming religious belief as an evolved tendency. But there are a lot of things which it is virtually impossible to understand by just looking around and being observant and thoughtful: weather, disease, earthquakes, existence, morality. Not only is religion in a position to fill in the gaps, but it may actually often be preferred to the true explanation because it’s more psychologically satisfying. Just because we evolved reason and a desire to explain things doesn’t mean we will always settle on the most accurate explanation.
An analogy would be poetry. Poetry of some sort is pretty much a human universal, but I don’t think it needs to be explained as an evolutionary adaption. Having evolved language, there was a situation where those people who could find ways to use it that were powerful—exciting, moving, funny—would be able to use it to gain status, in a broad sense. Or just find pleasure in it for themselves. The evolution of language created an opportunity; from that point, normal cultural development seems a sufficient explanation for the invention of poetry, story-telling and so on.
I think also it’s easy to talk rather glibly about something being a ‘universal’ human trait. Language is universal: if an adult human has no language, there is something wrong with them. The same is true of psychological traits like empathy or fear. It’s not clear to me that the same can be said of religious belief or a search for transcendence. it might be hard to find anyone who was completely free of irrational beliefs and superstitions, but there are plenty of people who aren’t religious. Not just those who are explicitly atheist or agnostic, either; even in societies where everyone is nominally the member of a faith, I would suggest there are plenty of people who are believers in name only, and people for whom it just isn’t very important.
Religious belief clearly isn’t counter-adaptive, and if it isn’t hard-wired, it is at the very least well-suited to the human way of thinking. But so what? The history of science is one long process of learning the hard way that our intuitions about how the world works are usually wrong.