Why smart people believe crazy stuff

It'd always been my impression that intelligence is rather strongly correlated with disbelief in the supernatural (whether in the form of religious belief or plain old superstition). I still think it is correlated but maybe not as strongly as I thought: I've recently met some smart people who believe pretty crazy stories.

And I don't just mean the odd mystically-inclined physicist who thinks the laws of nature are God or some such metaphor. I mean intelligent, educated, somewhat scientifically literate people believing pretty literally in a soul separate from the brain which survives the body's death and goes on to live in some alternative reality. Or some similar off-the-wall story: you get the idea.

There are probably many factors which make this particular mental setup possible but let me speculate as to one of the possibly most important factors. I actually hinted at the possible culprit above: "somewhat scientifically literate". I think it may not be sufficient to have basic secondary school scientific literacy to realize how much ideas such as astrology or an immortal soul are incompatible with the scientific outlook.

It doesn't much matter if you know the details of meiosis or are familiar with Heisenberg's uncertainty principle as disconnected facts. You need to be aware of the scientific method as a means to build successively more adequate approximations of reality. You need to know that the whole of science hangs together, that you are not allowed to just pick and choose: accept medicine because it seems to work, but reject evolution by natural selection because it makes you feel like the world is a cold and unpleasant place.

There is also the fact that you have to be willing and able to ask the right questions and follow the answers to their conclusions. If you think science is mostly right, but there is something more out there you have to be willing to check if this something out there is actually a possible extension to already established scientific facts. For example you may think physics and biology are correct as such, but they just fail to mention the immortal soul, so you are free to believe in it. And you want to because it gives you a warm and fuzzy feeling and makes you less afraid of death. Well not quite.

There's all the well known problems with dualism. To dumb down, if the soul is supposed to control the body then it has to interact with it somehow. If it is material then it's just some part of the brain which science can study and explain, and it's unlikely to survive the death of the rest of the brain. If it's immaterial, then how can it have a causal effect on a material object like the brain? Energy doesn't come out of nowhere, and so on.

There's more prosaic implausibilities and inconsistencies. Do only humans have a soul? Which of the extinct hominins, if any, had it too? At which point in the evolution of our species did we acquire it? At which point during our embryonic development do we get it? As soon as conception? If so, then most soulful beings don't even get to be born, as most pregnancies end in an unnoticed early spontaneous abortion. You can probably try to speculate about answers to these issues, but I bet when you're finished you'd be left with a kind of soul that you'd no longer want quite so much to believe in.

And some smart people who don't know much outside high-school science plus their own narrow area of expertise might just not have come across too many ideas that would make them want to ask and be able to answer those kinds of questions. Some combination of philosophy of science, cognitive science, neuroscience, evolutionary biology and embryology are the ingredient that might be missing. My bet is that many people, smart or otherwise, have only a very vague idea or none at all about those areas. If they had more, I am willing to risk a guess that they would be a bit more picky about the crazy stuff they choose to believe in.

I guess some soul believers still wouldn't go all the way: probably some would be tempted by the Kurzweil-style singularity stuff as a last recourse -- I've just noticed right now that a relatively smart acquaintance of mine is into it. But no matter, its a progress anyway...