16. Are Christians less intelligent than atheists?

In July 2014, Ohio State University made the news when a quiz question from one of the school’s psychology classes implied Christians aren’t as smart as atheists. The question asked students to pick which scenario they found most likely given that a person named Theo has an IQ of 100 and a person named Aine has an IQ of 125 (IQ is a measure of intelligence). The correct answer? “Aine is an atheist, while Theo is a Christian.”¹ The story went viral and launched an online flurry of atheist commentary about the intellectual inferiority of Christians.

You may assume the Ohio State story is an example of baseless atheist bias against religion. That’s actually not the case. The question-and-answer choices were poorly worded, but it’s true that a number of studies have found a negative relationship between intelligence and religiousness—in other words, they suggest that the more intelligent a person is, the less likely they are to be religious. Many passionate atheists are well aware of these studies and use them as ammunition for their arguments that religion is for the poor, ignorant, and unintelligent.

Is this a valid claim? Can people legitimately say, based on these studies, that Christians are less intelligent overall than atheists? Absolutely not. I have an MBA in marketing and statistics and have taught university-level market research, so I’m a numbers geek… one who’s a little too excited to set the record straight in this chapter.

Before we move on, 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 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. This chapter will help you do that.

What Exactly Do These Studies Say?

There are two major studies people typically reference when this subject comes up—one at the country level, and one at the individual (person) level.

Country-Level Study Findings

In 2009, researchers compared the average national IQ with the national percent of atheists for 137 countries around the world.2 This analysis showed a significant positive relationship between those two measures: the higher the average national intelligence, the higher the percent of atheists in a given country.³ There are two key things you should know about this frequently quoted study.

First, the validity of national measures of intelligence and atheism is questionable. Measuring national intelligence is a controversial area of study due to the complex interaction of cultural factors such as environment, education, literacy, nutrition, and health care.⁴ This means that IQ numbers will vary across nations due to a variety of factors, making cross-country comparisons of intelligence extremely difficult, if not impossible.

Calculating a reliable estimate of the percent of atheists in a country is equally difficult. The researchers themselves acknowledged four problems with the data set used to estimate atheist percentages: low response rates, weaknesses in random sample selection, regime or peer pressure influencing responses, and problems of terminological variation between cultures over words such as religious or secular.⁵ No data is perfect, but the data used in this study is especially subject to concern.

Second, a more detailed analysis shows that the relationship between atheism and intelligence is limited to countries within a specific national IQ range. For a moment, let’s ignore my last point and assume the IQ and atheism measures for the 137 countries are reliable. Is the reportedly strong relationship between intelligence and atheism accurate based on the data points used? Yes and no. I obtained the raw country-level data from the published research study to dissect the reported results. While it’s true that the data as a whole shows a relationship between national intelligence and atheism, a closer analysis shows that this effect is mostly limited to countries with a national IQ between 85 and 95. In the 63 countries with an IQ less than 85 (almost half of the total), there is a statistically zero relationship between IQ and atheism.6 In the 36 countries with an IQ of 96 or greater, there is also a statistically zero relationship between these measures. Only in the 38 countries with an IQ between 85 and 95 is there a statistical relationship between IQ and atheism. These are predominantly Central Asian, Southeast Asian, and South American countries.

So what’s the bottom line? Taking the questionable data as it is, the only thing we can conclude is that in a specific range of national IQ levels there may be a weak relationship between IQ and atheism—and the countries falling in that range are almost all in three specific regions of the world (which suggests underlying region-specific factors). This is hardly conclusive.

Individual-Level Study Findings

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.⁷ 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.”8

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 are 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 look at the results, it’s important to note that combining 63 individual studies is problematic. The studies varied extensively on:⁹

• 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: 23 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.

Cornell statistics professor William M. Briggs summarized the problem with this variety, 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.”10

Methodological concerns aside, let’s assume for a moment that it’s valid to combine the results of these 63 studies. Ultimately, there were 2 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 noncollege). 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.¹¹

• Religious belief has almost no relationship with intelligence in the precollege years (presumably because beliefs are more influenced by parents).

• Religious belief has a weak negative relationship with intelligence for college and noncollege adults (the higher the intelligence, the less likely a person is to have religious beliefs).¹²

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

If you’re not a numbers person, your head might be spinning a bit right now. That’s okay—consider this a reference chapter to revisit when the subject comes up. You’ll be happy to know we’re all done with the data now. But before we call it a day, it’s important to consider what the Bible says on this subject too. Referencing what Scriptures say about intelligence and faith won’t get you far in a conversation with an atheist (which is why you need to understand the data), but as a Christian, it’s important to know what God has told us.

What Does the Bible Say About Intelligence and Faith?

The Bible is clear: Belief is not a function of intelligence. Scripture says:

• We are born with a spiritually dead mind (Ephesians 2:1).

• People without the Holy Spirit’s leading do not accept the things that come from God and consider them foolishness (1 Corinthians 2:14).

• People think in futile ways and can be darkened in their understanding due to a hardness of heart (Ephesians 4:17-18).

• The mind governed by the flesh is hostile to God (Romans 8:7).

• Because of these realities, people are unable to come to God without His prompting (John 6:44; Romans 3:11).

The Bible also makes it clear, however, that we shouldn’t check our minds at the door. Thinking, in its appropriate place, is a core part of faith. Jesus told us to “love the Lord your God with all your heart and with all your soul and with all your mind” (Matthew 22:37). The apostle Paul told the Corinthians, “Do not be children in your thinking. Be infants in evil, but in your thinking be mature” (1 Corinthians 14:20). The kind of thinking that the Bible repeatedly cautions against is a purely self-reliant thinking. Make no mistake: Christians are called to a Spirit-enabled use of our minds.

No Need for Shame

As a Christian, you may wonder why anyone ever gets caught up in discussions about who’s more intelligent. After all, as I pointed out earlier, the most intelligent people (whoever they might be) don’t necessarily have all the right answers. But atheists often bring this up to show that religion is for ignorant people who don’t know better. It’s an emotionally impactful claim that can shame your kids for being Christians and make them question their own judgment—an outcome truly unnecessary given the actual data. Make sure your kids have the full picture: Only about half the studies ever conducted on the topic have suggested that more intelligent people are less likely to be religious, and, even in those studies, the relationship between intelligence and religiousness is very weak.