Are religious people cognitively different from those who are atheists?
Of course they are.* Just as people who like thyme are cognitively different from those who do not like thyme. What else would cause them to profess diverging beliefs?
Now, are there differences in the general architecture of their minds? That comes down to definitional issues: Would you say 'No general difference, they have all the corresponding brain areas'. Or do you zoom in to the level on which individual beliefs necessarily manifest themselves in conglomerates of grandmother-type neurons and assorted structures, then call that a general difference?
Would you count the correlation between anthropomorphizing your environment and not having a lot of knowledge of said environment, a la caveman versus grad student? In that case if you were able to differentiate educational sophistication based on e.g. future brain imagining methods, you could by proxy predict religious beliefs. Good enough to answer the original question in the affirmative? It would also predict ability to drive a car.
Supposing there were a difference in the general architecture on a level that most people would call "general architecture" (?), we could then try to ascertain the relative importance of hereditary ("nature") versus post-natal (or even in utero) environmental ("nurture") factors.
Going down that avenue, we'd note that the genetic drift and other genetic evolutionary factors for the last couple of centuries have been negligible (make that since the cro-magnons, if you're feeling charitable). Yet the proportion of religious believers has varied enourmously over short spans of time, even in homogeneous / steady gene pools (or subgroups, disregarding migration) such as Western Europe.
That leaves the question whether those environmental factors that do lead to different religious affiliations - by necessity changing your cognitive characteristics - effect a large enough change for that change to be classified as a "general architectural" change or not.
Apologizing for the verbosity, my point is that different valid studies may well show rigorous but contradictory results for that precise question, rooted in the exact formulation of what constitutes different general architectures. Unless someone is a dualist, all beliefs must leave their marks somewhere in your wetware, changing it. One of my biggest peeves in the field is just that - prima facie interesting niche results that are mutually incompatible because of minor variations in the problem definitions.
(* For sufficiently large concepts of "different")
Are religious people and atheists together different from people who don't care about religion?
None of them.
'In 2006 Steven Pinker wrote an unfavorable review [12] of Lakoff's book Whose Freedom? The Battle over America's Most Important Idea. Pinker's review was published in The New Republic. Pinker argued that Lakoff's propositions are unsupported and his prescriptions are a recipe for electoral failure. He wrote that Lakoff was condescending and deplored Lakoff's “shameless caricaturing of beliefs” and his “faith in the power of euphemism”. Pinker portrayed Lakoff's arguments as “cognitive relativism, in which mathematics, science, and philosophy are beauty contests between rival frames rather than attempts to characterize the nature of reality”. Lakoff wrote a rebuttal to the review [13] stating that his position on many matters is the exact reverse of what Pinker attributes to him. Lakoff explicitly rejected, for example, the cognitive relativism and faith in euphemism described above, arguing in favor of a deeper understanding of rationality that discards the modal logic conceptualization of rationality in favor of the better supported framing conceptualization'
A paper on the psychology of religious belief, Paranormal and Religious Believers Are More Prone to Illusory Face Perception than Skeptics and Non-believers, came onto my radar recently. I used to talk a lot about the theory of religious cognitive psychology years ago, but the interest kind of faded when it seemed that empirical results were relatively thin in relation to the system building (Ara Norenzayan’s work being an exception to this generality). The theory is rather straightforward: religious belief is a naturally evoked consequence of the general architecture of our minds. For example, gods are simply extensions of persons, and make natural sense in light of our tendency to anthromorphize the world around us (this may have had evolutionary benefit, in that false positives for detection of other agents was far less costly than false negatives; think an ambush by a rival clan).*
But enough theory. Are religious people cognitively different from those who are atheists? I suspect so. I speak as someone who never ever really believed in God, despite being inculcated in religious ideas from childhood. By the time I was seven years of age I realized that I was an atheist, and that my prior “beliefs” about God were basically analogous to Spinozan Deism. I had simply never believed in a personal God, but for many of earliest years it was less a matter of disbelief, than that did not even comprehend or cogently in my mind elaborate the idea of this entity, which others took for granted as self-evidently obvious. From talking to many other atheists I have come to the conclusion that Atheism is a mental deviance. This does not mean that mental peculiarities are necessary or sufficient for atheism, but they increase the odds.
And yet after reading the above paper my confidence in that theory is reduced. The authors used ~50 individuals, and attempted to correct demographic confounds. Additionally, the results were statistically significant. But to me the above theory should make powerful predictions in terms of effect size. The differences between non-believers, the religious, and those who accepted the paranormal, were just not striking enough for me.
Because of theoretical commitments my prejudiced impulse was to accept these findings. But looking deeply within they just aren’t persuasive in light of my prior expectations. This a fundamental problem in much of social science. Statistical significance is powerful when you have a preference for the hypothesis forwarded. In contrast, the knives of skepticism come out when research is published which goes against your preconceptions.
So a question for psychologists: which results are robust and real, to the point where you would be willing to make a serious monetary bet on it being the orthodoxy in 10 years? My primary interest is cognitive psychology, but I am curious about other fields too.
* In Gods We Trust and Religion Explained are good introductions to this area of research.
Considering the communities heavy reliance on such results I think we should answer the question as well.