Intelligence and Religiosity

A scholarly article appeared a few days ago that argues intelligent people are less likely to be religious than, um, less-intelligent people. It’s received a fair bit of attention, for obvious reasons.

The article, “The Relation Between Intelligence and Religiosity: A Meta-Analysis and Some Proposed Explanations,” by Miron Zuckerman, Jordan Silberman, and Judith A. Hall, was published online in Personality and Social Psychology Review on August 6th. If you have access to a university library, you can read it for free; if not, you can download it for $25 USD. Be warned: much of this paper is a discussion of statistical analysis. I don’t know enough about that to engage in a critique of their methodology, but their discussion of methodological issues is graspable if you’re willing to work your way through it. Here is the abstract, which is available for free at


A meta-analysis of 63 studies showed a significant negative association between intelligence and religiosity. The association was stronger for college students and the general population than for participants younger than college age; it was also stronger for religious beliefs than religious behavior. For college students and the general population, means of weighted and unweighted correlations between intelligence and the strength of religious beliefs ranged from −.20 to −.25 (mean r = −.24). Three possible interpretations were discussed. First, intelligent people are less likely to conform and, thus, are more likely to resist religious dogma. Second, intelligent people tend to adopt an analytic (as opposed to intuitive) thinking style, which has been shown to undermine religious beliefs. Third, several functions of religiosity, including compensatory control, self-regulation, self-enhancement, and secure attachment, are also conferred by intelligence. Intelligent people may therefore have less need for religious beliefs and practices.

In a nutshell, the article is a detailed review of other studies on the relation between intelligence and religiosity; the authors have not done a new survey. The authors note that the first such study was published in 1928 and that there have been several large-scale studies in the last decade. The authors review 63 studies in all; 53 showed negative correlations between intelligence and religiosity. In other words, most of the studies showed that “the higher a person’s intelligence, the lower the person scored on the religiosity measures (p. 9).” The authors consider various factors, such as whether education levels, restricted samples, etc. account for this negative correlation. They argue that the relation holds even after taking those factors into account.

A few observations:

The idea that intelligence and religiosity are related is not new. The beliefs of the uneducated masses were often regarded as mere superstition as compared to the proper religion practiced by the elite classes. In the 18th century, anti-religious writers argued that the ignorant needed religion; only the enlightened could live moral lives without it. Of course, before the 20th century no one was thinking in terms of IQ, but the pattern of devaluing whatever the lower classes believe while privileging the beliefs of the educated members of society is consistent throughout Western history. The modern interest in intelligence and religiosity is, I think, an iteration of the pattern, with a different sort of class division being created that separates high-IQ individuals from those with lower IQs — and between the religious and the non-religious.

The authors point out that most explanations of the negative relation between intelligence and religion “share one central theme — the premise that religious beliefs are irrational, not anchored in science, not testable and, therefore, unappealing to intelligent people who ‘know better’ (p. 3).” They do criticize this premise, but not, I think, as strongly as it deserves. It seems to me that the entire enterprise of trying to establish what the relation between intelligence and religiosity is presupposes a) that there is one; b) that it would be useful to know what it is. The anti-religious agenda and snobbery are obvious.

One “explanation” that has been offered for the relation between intelligence and religion is that atheism “is evolutionarily novel,” and since intelligent people are better able to cope with evolutionary novelty, they become atheists. The authors of this article cite Kanazawa as the proponent of this theory, which is based on the idea that religion developed because it conferred an evolutionary advantage. What’s important to consider here is that any theories about how religion developed among pre-historical humans are speculative. Anthropologists have different interpretations of what, for instance, the famous Venus figurines mean (goddess figures or pornography?) and what the intent behind cave paintings was. We have to speculate, because there are no written sources to tell us what pre-historic humans were thinking. Furthermore, what evidence is there to show that religion was evolutionarily advantageous or that atheism didn’t exist? The idea that religion evolved suggests that humans were originally not religious, which would make religiosity more novel, in the evolutionary sense, than non-religiosity. Finally, it’s woefully unclear what is meant by atheism being evolutionarily novel, because the article contains no historical or anthropological background whatsoever. It’s actually unclear what the authors mean by atheism, since they never define it and tend to slip from “non-religious” to “atheist” without commenting on the difference between the terms.

The authors discuss several other “explanations,” such as the idea that intelligent people are non-conformists. Their own favoured “explanation,” which they claim is new, is that religion fulfills certain functions, such as alleviating loneliness. Intelligence fulfills the same functions, or at least leads to a person being able to satisfy their needs without religion. So religion and high intelligence are functionally equivalent. For example, a person who is less intelligent, and  feels lonely, will be comforted by a secure relationship with God. An intelligent person, on the other hand, is statistically more likely than a less-intelligent person to get married and to stay married. The authors reason from this as follows: “if intelligent people are more likely to be married, then they may have less of a need to seek religion as a refuge from loneliness (p. 20).” It’s the same sort of reasoning that has led some scholars to suggest that sports fandom, nationalism, etc. are religions, because they fulfill the same functions as religion.

The functional explanation seems very forced to me. Part of the problem is that the authors don’t discuss any qualitative information; there’s nothing here about religious and non-religious (or intelligent and less-intelligent) people’s own explanations of their behaviour and beliefs. What we get instead is a convoluted attempt to explain a statistical correlation by other statistical correlations.

What are the implications of this research? It reinforces the notion that religiosity is a characteristic of unintelligent people and that non-religious individuals are more “evolved” than religious people. Remember the “Brights” movement? ( Perhaps I’m being alarmist, but this kind of language, especially the use of evolution as an “explanation,” gives me the willies. We’ve heard this before, haven’t we? What’s happening is the development of a discourse that suggests atheists are better humans — that they represent evolutionary progress. Believers, in this model, become flawed, degenerate humans. Expendable, perhaps.

The fact that women are, overall, more religious than men adds a disturbing wrinkle to the intelligence-religiosity relation. If women tend toward religiosity, and religiosity is connected with lower intelligence, it’s not a great leap to the conclusion that women overall must be less intelligent than men. Why else would they be more religious?

No doubt, many atheists and other non-religious people would say that these studies are simply practicing fair turnabout on the centuries-old view of unbelievers as irrational, immoral monsters. But any work that suggests an entire category of humans is less intelligent than another is playing with fire. We need to think hard about the agendas and consequences of such research.

2 thoughts on “Intelligence and Religiosity

  1. François V. Pageau

    Furthermore, I am always suspicious of studies which try to measure “intelligence”. A number of tests are blatantly biases towards the cultural context of their creators, and there may be many different kinds of “intelligence” which are not correctly measured by those tests.


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