Are Christians Less Intelligent Than Atheists? Here’s What All Those Studies REALLY Say

Are Christians Less Intelligent Than Atheists? Here’s What All Those Studies REALLY Say

Today I want to shed light on a nasty little “fact” that regularly makes the rounds online:

Studies show that Christians are less intelligent than atheists.

This statement is proudly tossed about by atheists who want to reinforce their claims that religion is for the poor, ignorant, and unintelligent.

And you know what? The statement is true…a number of studies have found a negative relationship between intelligence and religiousness (the more intelligent a person is, the less likely they are to be religious).

Does that mean people can legitimately say, based on these studies, that Christians are less intelligent than atheists? Absolutely not. 

I have an MBA in marketing and statistics and have taught university-level market research, so I’m a professional numbers geek…a numbers geek who dug into all these research studies to find out what they REALLY say. Today I want to set the record straight.

Before we get too far, however, I have to point out what is hopefully obvious: Even if we could reliably measure which group is smarter, the answer wouldn’t tell us anything about the truth of Christianity; intelligence doesn’t equate to always having the right answer.

Theoretically, we could end all conversations on this topic by pointing that out. But if your child asks you one day why Christians aren’t as smart as atheists, do you really just want to reply, “Well, that doesn’t mean Christianity isn’t true”? We owe it to our kids to be able to address the claim itself.

So here we go. Please bookmark this page as a resource that you can link to next time you see someone claim that Christians are less intelligent than atheists!

What 63 Studies on Intelligence and Religiousness Really Say

In 2013, researchers from the University of Rochester and Northeastern University pulled together all past studies conducted on the relationship between religiousness and intelligence at the individual (person) level. Of the 63 studies identified:

  • 35 showed a significant negative relationship between intelligence and religiousness (the more intelligent a person was, the less likely they were to be religious).
  • 2 showed a significant positive relationship between intelligence and religiousness (the more intelligent a person was, the more likely they were to be religious).
  • 26 showed no significant relationship between intelligence and religiousness.

In other words, only about half of the 63 studies suggest that the more intelligent a person is, the less likely they are to be religious. The other half of the studies don’t show that at all. The researchers themselves acknowledged, “The relation between intelligence and religiosity has been examined repeatedly, but so far there is no clear consensus on the direction and/or the magnitude of this association.”

First major takeaway: The common claim that studies have shown repeatedly that religious people are less intelligent is highly misleading. It ignores the results of almost half of the studies conducted. Overall, the results have been very inconclusive.

The goal of the researchers in 2013 was to look at these studies as a group for the first time, in order to better quantify the nature and magnitude of the relationship between intelligence and religiousness. Before we even look at the results, it’s important to note that combining 63 individual studies is very problematic. The studies varied extensively on:

  • Who was studied: Some studied precollege teens, some studied college students, and some studied noncollege adults (people recruited outside an academic context).
  • How many people were studied: Sample sizes ranged from 20 to more than 14,000.
  • When the studies were conducted: The studies were done over an 84-year span of time (the earliest study was conducted in 1928 and the most recent in 2012).
  • What the studies measured: Some studies measured religious behavior (for example, church attendance and/or participation in religious organizations) and some measured religious beliefs (for example, belief in God and the Bible).
  • How the studies measured: Twenty-three different types of tests were used to measure intelligence (for example, university entrance exams, vocabulary tests, scientific literacy tests, etc.). Details weren’t provided on how exactly each study measured religious behavior and beliefs, but that surely varied extensively as well.

Generally speaking, combining such disparate studies is a statistical disaster.

Cornell statistics professor William M. Briggs summarized the problem, saying, “Data of every flavor was observed, data that should not be mixed without an idea of how to combine the uncertainty inherent in each study and in how, say, kinds of IQ measurements map to other kinds of IQ measurements. In other words, they mixed data which should not be mixed, because nobody has any idea how to make these corrections.”

Methodological concerns aside, let’s pretend for a moment that it’s valid to combine the results of these 63 studies. Ultimately, there were two factors researchers found to be significant in the relationship between intelligence and religiousness. The first was the life stage of who they studied (precollege, college, or non-college). The second was the measure of religiousness (behavior or belief). The results suggested:

  • Religious behavior, such as church membership, has almost no relationship with intelligence at any life stage.
  • Religious belief has almost no relationship with intelligence in the precollege years (presumably because beliefs are more influenced by parents).
  • Religious belief has a very weak negative relationship with intelligence for college and noncollege adults (the higher the intelligence, the less likely a person is to have religious beliefs; the weak relationship is a -0.17 correlation between intelligence and religious beliefs for the college studies and a -0.20 correlation for the noncollege studies).

Second major takeaway: The results suggest a negative relationship specifically between intelligence and religious belief for adults, but the mathematical magnitude of that relationship is very small. Almost all variation in religious belief amongst individuals is explained by (unidentified) factors other than intelligence.

In review, here’s what you need to know next time you see someone make this claim:

Over the last 80+ years, many studies have been done on the relationship between intelligence and religiousness. In 2013, researchers pulled together all the ones that quantified that relationship. Of the 63 studies they identified, roughly half showed no relationship at all. The other half showed at least some kind of negative relationship (the more intelligent you are, the less likely you are to be religious). That said, statistically speaking, it’s not very helpful to simply know there is “some kind” of relationship. You have to know how strong the relationship is to know if it matters. Researchers combined the results of all these individual studies to evaluate that question overall and found the strength of relationship to be very weak.

What do I mean by very weak? A -.17 or -.20 correlation is considered to be a trivial or negligible relationship by most statisticians. In other words, hardly worth mentioning.

Now you have the whole story. But one last note. Please do not share the following article when you see an atheist make claims about Christians being less intelligent: Of 10 Highest IQ’s on earth, at least 8 are Theists, at least 6 are Christians. I regularly see Christians replying to atheists with that link and it makes me cringe every time. It doesn’t matter if the 50 or even 1000 most intelligent people on Earth are theists or Christians—that doesn’t statistically mean anything about the relative intelligence of Christians as a group. Engage instead on the studies underlying the atheists’ claims by sharing this analysis.

Any questions?

23 thoughts on “Are Christians Less Intelligent Than Atheists? Here’s What All Those Studies REALLY Say”

  1. Thanks a lot for the post! I’m no statistician, but I wanted to ask a question involving that often quoted article about the top ten IQs. I would have thought that one of the problems with averaging the “intelligence” of all theists together and comparing that to the “intelligence” of all atheists together would be unfair since atheism is usually taught or learned and not simply assumed while nearly everyone alive simply grasps or assumes theism. That would mean that atheists, just by the nature of the thing, typically have some form of education while theists are lumped together with 95ish% of everyone alive including the poor, those from third world contries, or otherwise just uneducated. If that’s correct, then wouldn’t a more fair evaluation of “intelligence” be comparing those who are “smart” or have the same level of intelligence or education and see what worldview is preferred at that level? And in that case wouldn’t comparing the ten people with the highest IQs have some advantage since it alleviates some of the sociological baggage involved in adopting a worldview? I want to emphasize that I’m not myself familiar with statistics so I want to learn here. Thanks so much for your post and ministry.

    1. Hi Kevin,

      Good questions! There are actually several embedded in there, so let me address them individually.

      First, let’s talk about that link about highest IQs. When people make the claim that Christians are less intelligent than atheists, they are talking about/interested in the average intelligence of all people with those respective beliefs. Looking at the ten people with the highest IQs isn’t a finding that you can extrapolate to any broader conclusion. For example, what if the 10 ten smartest people believe in God, but the next 10,000 smartest people are atheists. Of the 10,010 smartest people in the world, 99.9999% would be atheists. Do you see the problem mathematically of looking at 10 people? It’s an arbitrary cut-off that isn’t a representative sample of any group you can make broader conclusions about. In statistics, you can’t sample the whole world, so you have to take a representative sample that is valid to draw bigger conclusions from. That also goes the other way – atheists frequently point to memberships in science organizations to show that these smart people overwhelmingly don’t believe in God. But that’s not a representative sample that you can extrapolate from to see about religiousness and intelligence. At the most, you might conclude that experts in certain scientific fields are less likely to believe in God.

      Now, as to third world countries, that is a different issue. These studies are samples within one country (the United States). There are certainly country-specific factors that may change the relationship between these measures WITHIN a given country. In most third world countries, the rate of atheism is too low to be accurately measured. There was a study done of 137 countries, looking at the relationship between average country IQ and intelligence. I discuss that one in my book too, but the bottom line is that only a handful of countries show a relationship between the measures (within a specific IQ range).

      Last, in order to measure correlation (relationship) between the measures, you need a variety of data points. For example, let’s say you looked at the beliefs of everyone with a certain high IQ and found that they have all kinds of beliefs and there was no relationship with atheism. You might draw the conclusion that intelligence doesn’t matter and proudly walk away. But if you were to then do a sample of all low-IQ people and find that they are all Christians, you would have to draw quite a different conclusion. So in order to determine possible relationships between IQ and religious beliefs, you have to have data points across the whole range.

      I hope that helps. Let me know. 🙂

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  3. Oh wow, you know, I have never heard this little “fact”. I’d probably never hear it to my face since I’m a real life rocket scientist and probably much smarter than the person who’d be, ahem, dumb enough to say that. But I’m surprised I haven’t seen quoted in literature … Thanks for sharing, it’s something I will have to keep in mind.

    1. LOL A real life rocket scientist…that is awesome. 🙂 If you Google “Are Christians less intelligent than atheists?” you’ll see all kinds of articles from 2013 when this meta-study came out. Disappointingly, even in Christian articles (such as Christianity Today) they take the findings as a given. That’s why I wanted to dig in to understand what was really going on.

  4. I find atheists are far superior in arrogance more than anything. They know how to mock, post sarcastic memes, debate with those less “enlightened” and “evolved” as they are. But I wonder how good they are in the area of relationships which is where most folks live.

    1. Well, plenty of Christians are arrogant as well. I don’t think that’s the domain of any one group. I think rather than going back and forth between Christians and atheists about who’s better at what, it’s best to engage on the data itself (as in this post).

  5. I’m pretty sure that the very small correlation between atheism and intelligence is because of our education system, not any inherent superiority of atheism. People who are more intelligent tend to go to college and to get more advanced degrees. And since our college system is largely populated by atheists and teaches humanism, evolution, and moral relativism quite blatantly, it is no surprise that some of our more intelligent people adopt atheism – not because it’s intellectually superior, but because it has the appearance of being intellectually superior due to a greater percentage of people in academia that are atheists and are the ones doing the teaching.

    1. I think that is true within certain fields (for example, biology). Interestingly, however, the researchers in this meta-study looked at education where possible and found that it wasn’t a factor. I can’t remember the specifics off the top of my head, but I do remember that they found the IQ measures were sufficient to capture any variation in education (the correlation between them is strong, so one serves as a proxy for the other).

  6. Thanks for this. It will be a great resource WHEN the topic comes up with our kids.
    When I read it, the thing that comes to mind is that the focus on having a conversation on intelligence can be so vague. Firstly, there are so many different kinds of intelligence. A person can be ‘book smart’, but all they have done is memorised a text that they have been taught, or perhaps they have read it themselves. IMO, true intelligence is in the life application of the subject learned. Many people don’t have the opportunity the receive a university or college education. It certainly doesn’t mean they’re not intelligent. Some people have dyslexia…which means simple spelling of words will always be a challenge for them, but they are some of the most intelligent people you will ever meet. They have an incredible capability to ‘think outside the box’ and offer insight that other ‘normal’ people don’t see at all. There are so many different ways we could study ‘intelligence’….and even then, that is only a small part of who we are. So many other important factors come into play as far as I’m concerned… These things are Love, humility, compassion, mercy and grace. How do the intelligence studies factor these important characteristics into the equation. My point—intelligence cannot be measure on it’s own. I think that’s your point in the article also. Thanks for writing…I will refer back to this with my boys. Lord Bless.

    1. Thanks Carla, I’m glad it was helpful!

      One criticism many have mentioned about all these IQ measures is what you raised – that there are different types of intelligence and all these measures are based on what’s called analytic intelligence. There are definitely different kinds of intelligence, and those kinds of intelligence are not traditionally measured by IQ studies. That said, I would caution anyone about using that as a “defense” about the relative intelligence of Christians – it seems to suggest that it’s legitimate to conclude these studies say Christians are less intelligent, but we’re only less intelligent in certain ways. There is NO need to suggest that given the actual findings, so we shouldn’t propagate the idea. We can address the actual data instead, as outlined here.

      Thanks for your comment!

      1. I see what you’re saying.. My point is also that intelligence measured by human standards is simply not really important. It is rooted in pride. Let the atheists have their so-called ‘intelligence’….it’s really all they have to cling to.
        Our relationship with God is fundamentally spiritual. God interacts with us in different ways including with our intellect, bu the ‘real us’ is spiritual, as God is Spirit. We can certainly interact with people using our intellect, and that may serve to cause people to ‘pause’ long enough to consider God as ‘real’, but it will never serve to bring someone to Christ. It’s not an intellectual conversation. It includes using the ‘intellect’, but it is not intellectual. I believe an atheist wants to say that religious people are not intellectual…because it’s hurtful. It’s not a nice thing to say. It’s them fighting back. Of course they’re completely missing the point…there is a battle to fight but they are on the wrong side. They do however have a loving Creator who desires to know them and to save them. Intellect can serve to reason with them, but it will never bring them to Christ. The Holy Spirit does that. Humility is key here. Can an atheist turn from their prideful ways to humility to see their need for a Saviour? The answer of course is ‘Yes they can’…They only need to listen to the gentle drawing of The Holy Spirit and respond to that. I think it will serve us well to know our identity In Christ…. Blessed, Chosen, Adopted, Accepted, Redeemed, Forgiven and Loved. OH how I want my kids to know that by the time they move out. It doesn’t matter what people say, it matters what God says. Prejudices and lack of understanding comes in all forms from all areas and circumstances of life. I just honestly think their are more important conversations to have than the fight for intelligence. When my kids are faced with this type of response from an atheist, I want their identity In Christ to be so deeply ingrained into their hearts that they will not be shaken, offended, insulted or intimidated. They will simply know who they are. I have two boys, and they are Sons of the God of all Creation…He is the KING of kings and the LORD of lords. He is the Alpha and the Omega. That’s their identity… so it really doesn’t matter what some random atheist says.

  7. I am one of those ‘unintelligent Christians.’ I wonder how far I could have gotten in school if I was more intelligent, like the atheists. As it is, I only have a Master’s Degree in Psychology. Bummer! If I only had a brain!

    1. 🙂 I would think that psychology is one of the fields dominated by nonbelievers, since there is so much interest in explaining all beliefs away by brain activity. Have you found that in your experience?

      1. I think for the most part, the ‘leaders’ and ‘forefathers’ in psychology are definitely secular, trying to explain and teach how we can heal ourselves and manage on our own, etc. And there is a focus on finding either chemical, hormonal, physical, or environmental causes of symptoms, while ignoring any supernatural, sin, or soul/spiritual factors. You really need to be sure to get a Christian therapist if you are dealing with really deep, heart issues because a secular therapist will not really explore the spiritual side or know how to apply God’s Word. God’s truth is what will bring the most lasting, real healing, not man’s attempts to solve our own problems. That can only give us temporary solutions. I actually found this post funny, if those studies were not so pathetic. If people could only know how biased most studies are and how skewed the results can be because of a multitude of factors (such as you pointed out here), most of us would have very little faith in science. Many studies are not very ‘scientific’ at all. We can skew and twist just about anything to say what we want it to say (just think of all those studies that say there is no real difference between organic food and pesticide-laced, GMO food. We all know better, but ‘science’ can look at whatever factors they want and then claim it proves their point.) Anyway, I had to laugh at the patheticness of studies like these and shake my head that the mud-slinging has gotten to this ridiculous low. I guess it’s whatever helps them sleep better at night. It’s just too bad that we all can’t have more respect for each other, since we are all humans and have feelings and are smart in our own ways.

        1. And as you pointed out, intelligence does not mean we have the right answer. In the end – if God is real and the Bible is true, as I believe it is – it is not our intelligence that will matter. It is not what we know, but Who we know. And God uses the simple to confound the wise. A trusting heart that believes in Him will find eternal peace with Him. But a brain full of knowledge might be too puffed up to have any room left for Him.

  8. Right away I quickly discount the premise of this article, because the definition of religious is relating to or concerned with religion. The definition of Christian is relating to or derived from Jesus Christ or His teachings, a Christian faith. Jesus did not come to found a religion. The first apostles were called Christian at Antioch because the represented Jesus Christ, hence Christ-ians or Christ like. Being religious does not make you a Christian and being a Christian does not make you religious. Please rethink the premise. That is why the atheists are correct. The religious are still searching for Jesus Christ. The true Christians have found Him!!!

  9. How do you account for the dearth in studies showing the religious as intelligent as compared to the opposite? I’ve noticed that you never discussed in detail the fact that there are only 2 of 63 studies that have a positive gradient regarding the change in intelligence versus religousity. Instead, you ignored a proper examination of that statistic and focused on the strengths of the relations between individuals and their professed religions.

    If 35 out of 63 means nothing as your misdirect implies, what is the meaning of 2 out of 63 for religious thinking growing in tandem with intelligence?

    1. I think you misunderstood what these studies are about. No Christian (rightly) claims that Christians are more intelligent than atheists. The Bible makes clear that faith in Jesus is not a matter of intelligence, so we would not expect to see a relationship where the more intelligent people are, the more faith they have. It’s simply NOT a matter of intelligence, so 2 studies, 0 studies or a thousand studies showing a positive relationship would not be expected or relevant. There is no dearth in studies showing that the religious are as intelligent as atheists. As this article discussed, that’s what half of them do show.

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  11. Does the negative correlation between religiosity and intelligence tell us Christianity is untrue? No, it doesn’t. It does however suggest it.

    Intelligence tests measure the ability to solve problems and to think rationally. These are faculties that are called upon in evaluating the truth of religious claims. In psychometrics, it’s well known that mental abilities of various kinds tend to correlate with each other; so, for example, vocabulary size correlates with the ability to complete number sequences. In fact, although the correlation between two subtests may be weaker or stronger, the correlation is always positive.

    So, if we consider one’s stance with respect to religious propositions as an intelligence test where the truth (or the rational belief) is the ‘correct’ answer, it would be very surprising if in this case true beliefs were inversely correlated with IQ, because there is no other context in which such a negative correlation has been observed. This isn’t dispositive, but it does seem to suggest that religious claims are not true. The correlation with intelligence can be thought of as a heuristic, but it’s a heuristic with an excellent record so far.

  12. IQ.
    Are IQ tests anything but a game?

    Mensa here in Norway says that Mensa Norway consists of the 2% most intelligent people in the country.
    They also say there is no exact definition as far as intelligence is concerned…

    Doesn’t seem to intelligent to say this…and that…

  13. Thank you for this well thought out post. I don’t identify as Christian, but I do tend to seek God primarily through Christian church/community mostly because it’s the religion I’m most culturally comfortable with, hence me reading and enjoying your blog.

    One factor that wasn’t discussed in the post that I think is important is the tendency toward critical thought and how that character trait affects both IQ and religiosity. Obviously critical thought is valuable and certainly pairs with academic achievement, but the tendency to doubt also probably predisposes a person to doubt religion, regardless of the ultimate truth. if we acknowledge that curiosity and tendency toward thinking for oneself will logically correlate with intelligence, AND that it will of course cause a person to question mainstream religious belief, it seems obvious that intelligence would correlate negatively with religiosity, even simply as a secondary effect.

    On the flip side, people who tend NOT to doubt are also disproportionately predisposed to religion simply because it is part of the mainstream, and they gobble it up without question. They are simply accepting the norm. Of course you may also have low IQ atheists, likely blindly following surrounding atheists, but because Christianity is more prevalent than atheism it only follows that MORE non-critical people would happen to be religious by proximity.

    Im pushed to reject dogmatic Christianity based on my doubts about the literal resurrection, as well as the moral implications of many unacceptable passages in the bible, but even as a nonbeliever I agree with much of your article. It signals enourmous lack of humility to claim that “smart” people aren’t religious simply because they “know more” or “figured it out”. I would only add this one additional argument about the correlation of the unrelated 3rd factor: tendency to doubt.

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