The myth of the smarter Atheist

Ever since I published my previous article on the average IQ of students by college major, I’ve received several requests to analyze the correlation between IQ and religiosity. Below, I’ve written up an analysis of the existing published literature on the topic. I hope this serves as a springboard for future conversation on the topic — and hopefully puts some tired myths to rest.

Country-level evidence

One of the few peer reviewed scientific articles I could find on the topic had the straightforward name, “Average intelligence predicts atheism rates across 137 nations.” This article analyzes IQ and religiosity data from “137 countries that represent 95% of the world population” and claims to show that nations with more intelligent citizens tend to have more Atheists. I plotted the data from that article below.

iq-vs-religiosity-worldwide

(for the statistics nerds, the R^2 on a linear regression = 0.352)

What we see is a fairly weak relationship between national religiosity and average national IQ. Once we get up to about 20% of the population being Atheist, the IQ of the population flatlines at around 100 from then on. Even worse, in the ~0% Atheist range, there’s a wide range of national IQs from 64 to 100+ — with a cluster of low-IQ nations that appear to be driving the “trend.”

If we focus on the lowest IQ nations in the above chart, we notice that several of them are poor nations in e.g. Africa. That led me (and others who have reviewed the topic) to wonder whether the wealth of a nation better predicts the average intelligence of its citizens. After all, the more wealthy the average citizen is, the more time they have to dedicate to intellectual pursuits.

iq-vs-gdp-worldwide

(R^2 on a linear regression = 0.449; income per capita data from GapMinder)

Indeed, if we look at income per capita instead of religiosity, we already see a much better correlation with average IQ. The correlation between religiosity and IQ is too weak to suggest that religiosity predicts intelligence on the national level. Anyone who claims otherwise is grasping at straws.

Individual-level evidence

Looking at national data is fine and dandy, but what about individual-level data? In another controversial research paper on the topic, Satoshi Kanazawa claimed to explain “Why Liberals and Atheists Are More Intelligent.” In this article, Kanazawa analyzed data from a longitudinal study following students from middle school through adulthood. Conveniently, the study includes information on how religious the students are and the results of a standardized IQ test. Kanazawa mashed those variables together and claimed to show that Atheists tend to be smarter. I created a less misleading version of Kanazawa’s plot below; judge the data for yourself.

iq_vs_religiosity_ind

This is where we have to think about effect size vs. statistical significance. The most religious adults had an average IQ of 97.14, whereas the atheist adults had an average IQ of 103.09. That may seem like a wide gap — 6 whole IQ points — until we remember that anyone in the IQ range of 90-109 is classified as having “average intelligence.” Thinking about this in practical terms: Would you be able to tell the difference between someone with a 97 IQ and someone with a 103 IQ? It’s highly unlikely.

So really, all Kanazawa showed is that the average person has average intelligence regardless of how religious they are. I’ll leave the discussion of why this guy’s work was published in the first place for the comments.

Conclusion

The take-away message? To my knowledge, no amount of research has shown that Atheists are notably smarter than highly religious folks. It’s time we put this myth of the smarter Atheist to rest.

Randy is a PhD candidate in Michigan State University's Computer Science program. As a member of Dr. Chris Adami's research lab, he studies biologically-inspired artificial intelligence and evolutionary processes.

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19 comments on “The myth of the smarter Atheist
  1. Previous post on the paper: http://epiphenom.fieldofscience.com/2008/10/atheists-are-more-intelligent-but-does.html

    I never had much patience with the straightforward conclusion. Not only for the weak correlation among the “atheist” countries, but because IQ is supposed to ideally measure general intelligence (g-factor), and the idea that there are brains that have a high value of this and low religiosity vs. log g and high religiosity never sat well. If would mean that the connection between upbringing and religiosity (which I understand to be solid) somehow connected on a larger scale with intelligence, and that just seem implausible to me.

    That is not to say that I don’t think that it is stupid to be religious, and that a higher intelligence makes it more likely a person will break free of religion. I do. Sue me.

  2. Josiah says:

    You mention effect size and statistical significance… but don’t calculate either, and then dismiss the findings. It really doesn’t matter whether the group means of both groups fall within the band that someone arbitrarily decided is the “average” (defined as what? 1 SD from the grand mean of IQ)?

    What matters is whether there is a significant relationship between religiosity and IQ and, as you mentioned, what the effect size is. But you haven’t provided those numbers.

    • Randy Olson says:

      Let’s just compare the means. Would you be able to tell the difference between someone with a 97 IQ and a 103 IQ?

      • Victor says:

        Sure I will by asking them to check IQ test.
        And if you’re asking about purely observational difference, than you’re assumption that nobody want is also incorrect.
        Statistically, we will. Definitely you should be able to realise difference between two crowds made of 103 and 97 IQ individuals.

        Imho, this post is non-scientific bullshit

      • sup says:

        Can you tell a difference between the median teacher and the median mechanic? Some Googling suggests that the IQ differences between the two professions is ~6 IQ points.

        Further, although Ashkenazi Jews account for 3% of the US population, they represent some 27% of Nobel Prize winners — and what’s their median IQ? ~107.5.

        • Randy Olson says:

          Some Googling suggests that the IQ differences between the two professions is ~6 IQ points.

          Let’s stick to published data on this topic, please. “Some Googling” is not passable.

      • Josiah says:

        Without knowing what the distribution of scores for IQ are – I have no idea. i.e. how many SD is that difference? The scores themselves are inherently meaningless.

        Regardless, I think that calculating the actual effect size would be helpful, and should be pretty simple with the raw data. Do you want to tackle it, or do you know if the raw data is available somewhere?

  3. Eric Wilson says:

    Thanks for analyzing this.

    As a Christian, there is a temptation to fight the myth, and to retweet these results. See! Christians aren’t dumb!

    But it is much more fitting to accept that I am nothing special, and to keep in mind that God prefers to call those that are not “wise according to the flesh” so that He can be more glorified.

    For you see your calling, brethren, that not many wise according to the flesh, not many mighty, not many noble, are called. But God has chosen the foolish things of the world to put to shame the wise, and God has chosen the weak things of the world to put to shame the things which are mighty; and the base things of the world and the things which are despised God has chosen, and the things which are not, to bring to nothing the things that are, that no flesh should glory in His presence. But of Him you are in Christ Jesus, who became for us wisdom from God—and righteousness and sanctification and redemption—that, as it is written, “He who glories, let him glory in the LORD.”

    –1 Corinthians 26-31

    So I actually have some agreement with Bjorn, but I would express it differently. I believe, based on God’s revealed word, that intelligent people are more likely to rebel against their Creator to the point of denying His existence.

    I will pray for you, Bjorn, knowing that as long as you live, you have opportunity to turn to Jesus in repentance.

  4. nobody says:

    >That led me to wonder whether the wealth of a nation better predicts the average intelligence of its citizens.

    You’ve got your cause and effect backwards here, my friend

  5. I’m sure in other models, the findings might even determine some religious cultures e.g India and Israel, have a disproportionate number of Nobel laureates. Jewish Nobel Prize Winners http://www.algemeiner.com/?p=143785 . The study then might be refined to those religious cultures that promote science over faith, scholarship and critical thinking over rote learning. Does this mean that some traditionally religious cultures promote higher critical thinking as opposed to those that stress faith over knowledge, e.g. Spain, Italy, Saudi Arabia? Faced with problems like medicine, space travel, rocket science, nuclear fission, etc. would you select your team of scientists from Liberty College, or M.I.T. ? If your child was fatally ill would you turn to Oral Roberts or Johns Hopkins? You might find candidates of equivalent I.Q. in either, but how individuals apply that intelligent advantage becomes a qualifier in and of itself.

  6. eMatters says:

    I realize this is a very small sample size, but my two conservative, Bible-believing Christian daughters just graduated from college. One had a 3.97 from the Honors College of a major state institution (in only 3 yrs). The other got a 4.0 from a private school. They have excelled at every standardized test they every took and got A’s in every science class.

    Also, with respect to the “intelligent atheists,” I love what this quote from J. Budziszewski, atheist-turned-Christian philosophy professor from the University of Texas: “Though it always comes as a surprise to intellectuals, there are some forms of stupidity that you must be highly intelligent and educated to commit. God keeps them in His arsenal to pull down mulish pride, and I discovered them all.”

  7. Paul Rubin says:

    Two questions:

    1. Why are there countries with average IQ as low as 70? Might someone be conflating education level with IQ?

    2. I wonder if government might be a meditating variable? Suppose that the intelligence/education level of the populace of a country correlates negatively with its propensity to have an absolutist/dictatorial government. (I have no data on this, but it seems plausible that less intelligent citizens would be more gullible, more susceptible to propaganda, or perhaps just happier to be told what to do.) Dictatorial governments frequently appeal to religion for a mandate for their actions, which can make the country uncomfortable for atheists, who may then either leave or decline to admit their atheism.

    This is all speculation on my part, but it might make for an interesting follow-up analysis.

    • Randy Olson says:

      1. Why are there countries with average IQ as low as 70? Might someone be conflating education level with IQ?

      I wonder if there’s sampling issues. One criticism of that data set is that it’s based on a fairly small sample in some countries, sometimes as few as 10-20 people.

      2. I wonder if government might be a meditating variable? Suppose that the intelligence/education level of the populace of a country correlates negatively with its propensity to have an absolutist/dictatorial government. (I have no data on this, but it seems plausible that less intelligent citizens would be more gullible, more susceptible to propaganda, or perhaps just happier to be told what to do.) Dictatorial governments frequently appeal to religion for a mandate for their actions, which can make the country uncomfortable for atheists, who may then either leave or decline to admit their atheism.

      A counterexample to this would be China, which is quite dictatorial but still Atheist. Regardless, I agree: this would be an interesting trend to investigate! The big question is how one would quantify “dictatorialness” of a government.

      • Paul Rubin says:

        With sample sizes as low as 10-20, you have to wonder if there’s some “convenience sampling” going on (institutionalized individuals, prisoners, political office holders) that might bias the IQ value downward.

        I agree that measuring “dictatorialness” might be tricky. Absence of an elected body of representatives would be one indicator, but not the only one. Propensity of critics to be put on trial or to simply “disappear” would be another, but would be hard to get data on. A measure of human rights (or human rights violations) might make a plausible surrogate.

      • Josiah says:

        China is not even mostly atheist, according to most of the polls I just looked at.

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The data visualizations on this blog are the result of my “data tinkering” hobby, where I tackle a new data analysis problem every week. If I find something interesting, I report my findings here to share with the world.

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