Paging through an issue of Skeptic Magazine (Vol. 15, No. 2, 2009) the other day, I came across the article 'Atheism Rising', by James Allen Cheyne. Cheyne made reference to a compendium of research which has shown an inverse correlation between religious belief and intelligence as measured by IQ.
Cheyne observes (ibid.):
"Correlations between measures of intelligence and reported religious belief are remarkably consistent. Approximately 90% of all the studies ever conducted have reported that .....as intelligence (as measured by IQ) goes up, religious belief goes down."
This doesn't appear so fantastic a claim, based on the statistics he cites, when one realizes that just a moderate IQ (105-115) should be able to see that talking snakes (as in the "Garden of Eden"), guys living in whales bellies, and a man who can walk on water...are all preposterous. No genuinely intelligent person could buy into any of these any more than a smart kid would buy into Santa Claus.
In more depth, Cheyne makes reference to a particular type of thought he calls ACH thinking - or abstract, categorical and hypothetical - which appears to be mostly missing from believers' and which figures prominently on many IQ tests (such as the Raven's and Wechsler Similarities tests). Such tests feature many questions which construct an abstract hypothetical from a particular category, then ask the person to predict the consequences, if any.
For example, some ACH type questions might be:
1) If Venus and Earth were to exchange orbits, what would happen as a consequence to each planet to change it from its current conditions?
2) If a hollow equilateral pyramid were to be able to "opened" up and spread out in two dimensions, how would it appear?
3) We observe the red shift of galaxy clusters and interpret cosmic expansion. What would we conclude if all galaxy clusters showed a blue shift- but only up to 1 billion light years distant and nor more?
4) If the gravity on Earth were suddenly decreased by half, how would this affect energy costs in two named modes of transportation?
5) Imagine a sphere turned inside out, how would it look in 3 dimensions?
None of the above are particularly "easy" but neither are they too difficult for a person aware of basic facts (e.g. that Venus is already closer to the Sun than Earth by about 1/3) but do require the ability to abstract from the conditions of the hypothetical to see the new situation, and assess it. This is the very ability that Cheyne shows is missing as one examines results for religious believers.
Why are believers missing this crucial component of thought which also, by the way, is essential for critical thinking? There are a number of reasons. For example, one may be that the honing of such skills was never possible, for example if they came from a home schooling environment. Another, more controversial, is that the very neural pathways that predispose them to belief or faith, are also the ones that inhibit predictive ACH conceptualizing.
An interesting aspect here, as Cheyne notes, is that many people - including believers- display quick wittededness and clear thinking, and also good vocabularies - but remained "uncomfortable with abstract or hypothetical thinking and found such thinking to be alien".
This feature certainly explains the disbelief and even anger of many religious believers to certain sceintific claims - such as natural selection, or the Big Bang. Their hypothetical and abstract brain apparatus simply can't process either (especially how randomness enters) and they often become enraged at what they perceive as insults to "common sense". In reality, what they are confronting is their own breakdown in ACH thinking.
What about those Christians and other believers who happen to belong to high IQ societies like Mensa, Intertel, and the Poetic Genius Society? I believe their cases can easily be explained by a latent psychological neediness that seeks to create a fantasy world with which they are more comfortable. In this sense, all their ACH thinking which normally would be directed into processing of real world problems, acts to create a (hypothetical) fantasy world instead.
They still score reasonably high on the standard IQ tests because perhaps they can do many more of the questions to do with verbal analogies, general analogies, geometric perception, ...than the ACH questions provided.
Lastly, one must bear in mind that correlation is not causation, so that merely because a religious believer scores low in ACH questions, or even lower generally in some IQ tests - doesn't mean he or she is a dummy. It may just be that the brain they have is not equipped to do scientific hypothesizing or veer into the realm of atheism. (For which one takes a no-nonsense hypothetical approach based on observing absolutely no divine attention to the world or cosmos, and hence an absence or at least the need to reckon a divinity into existence).
Fair enough, but at the same time, the religious ought not set their brain standards up as those everyone must aspire to.......or, go to Hell, say. We all possess different brains, arguably different types of intelligence, but that doesn't mean one is superior to the other.
Something to think about, not necessarily in an ACH manner!