Book Review: Intelligence (2015) by Stuart Ritchie

August 12, 2015

Stuart Ritchie


An Uphill Battle

It’s no easy task to explain why intelligence is so important. The reason for this is oddly enough that many highly intelligent people insist it’s not important at all. While their arguments are weak, their eloquence, learned references, and general cleverness, charisma etc, often conceal this, at least to the unsuspecting part of the reading public.

To show what he is up against the author, psychologist Stuart Ritchie, begins with a quote from the late left-wing intellectual Christopher Hitchens,

“There is…an unusually high and consistent correlation between the stupidity of a given person and [their] propensity to be impressed by the measurement of IQ.”

As some of you may have noticed, this is an illogical statement. Correlation, as Hitchens no doubt knew, is a mathematical measure of the linear relationship between two variables. So to speak of a correlation between stupidity and something else implies that he relies on some measure or estimate of stupidity – which would be a reversed IQ test – to make the point that such tests are useless.

Or as the author says, “Smart people don’t like the idea of intelligence.” Strictly speaking this isn’t true. It’s mostly Western, left-leaning intellectuals who don’t like this concept, but they have been the most vocal and influential in the debate. Their critique is of course political rather than scientific in nature and they have made pretty ugly straw men out of proponents of IQ tests and research.

The Factual Psychologist?

So what do you do if you’re already cast as the Villain before having spoken your first line? Like the “factual feminist” Christina Hoff Sommers, Ritchie’s strategy seems to be to counter politically biased and emotional arguments with plain facts. The facts being that intelligence, as measured by IQ tests, is highly heritable, stable across the lifespan and linked to a number of life outcomes most of us find very important, like level of education, work performance, income, crime, health etc. Critics dismiss this by saying that IQ tests simply measure the socio-economic status which these correlates reflect. But high heritability and stability makes a strong case for causality going in the other direction. We’re born with a certain amount of intelligence and differences in this regard will explain later differences in terms of education, health etc. And if you think these correlates are important, you’re simply forced to agree that the intelligence that contributes to them is important too.

This is not to say that intelligence is “all that matters,” as it says on the cover of the book (referring to the name of the series the book is a part of and not the title). Leadership effectiveness, for instance, correlates a modest 0.35 with IQ. And there are “facts” in this book that can be contested. Like the link between IQ and socially liberal attitudes, which has a more sizable correlation of 0.45. This is possibly due to the fact that most research is done in the West where these attitudes are popular, especially among politically correct university students who make up the common “convenience” samples. A similar case can be made against the inverse relation between IQ and religious belief, a weak correlation of 0.25 to begin with, but even weaker if you look at the research behind it, something I have covered in more detail in an earlier post here.

That said, I haven’t found much to remark on in this book. And besides facts relevant to the importance of intelligence and to the critique against the concept, Ritchie also presents lots of other interesting stuff, explaining the basics of intelligence research and how it relates to subjects like behavioural genetics, evolution, neuroscience etc. And the book is so well-written I doubt anyone without prior knowledge will have a problem understanding it.

The Norwegian Enigma

One of the most interesting studies the author mentions is one that suggest a case for environmental influence, and a pretty hefty one too. It concerns the addition of two additional school hours in Norway which took place in the 1960s. This reform appears to have added on average 3.7 IQ points per year, which is a very big effect. This is in line with a global trend of increasing test scores over the recent century, called the Flynn Effect – which coincides with more children going to school all over the world.

According to the author there is no current theory that explains this boost, or the larger Flynn Effect. It could be simply that training a skill will improve it. Like a naturally muscular person will be stronger than the average but even more so if he works out in a gym frequently. While this study may hold a clue to how we can boost intelligence, the author also mentions that similar projects (of which there have been many) have given short-term increases with no lasting impact on the adult person. The Norwegian IQ tests that showed this effect come from the military so it’s young adults who were in school not long ago. Still, it’s intriguing, given the big effect. I would have liked some more space devoted to this study, what other researcher say about it, if there have been follow-up studies later in life or anything else to corroborate the test results.

The Controversy

In the last chapter, Ritchie returns to the controversial aspects of intelligence research that he mentioned briefly in the beginning of the book. Presumably because at this point readers now armed with the facts will be less likely to have their brains hijacked by their emotions. This seems like a good strategy, although even better would have been to keep presenting the facts and simply put the critics in the historical overview at the beginning. After all, most of the prominent opponents of intelligence testing are now dead or very close to death (no offense, we’re all headed there). That way he could have ended the book by highlighting interesting research areas and discuss future directions.

Instead the author tries to reason, coax, and negotiate with the critics, which to me implies that the facts somehow don’t hold up on their own (which they do). For instance, he mentions that Nazi doctors discovered the link between smoking and lung cancer, and that this finding is valid and useful regardless of who uncovered it. True, but in the very next sentence he goes on to say, “Also, it should be remembered that not all of the history of intelligence testing is tainted by eugenics,” thus undermining the point he just made. Or he tries to be nice by saying that differences in intelligence “might be influenced in part by biology,” when he has already stated that heritability trends toward 0.8 in adults.

Adopting the emotional arguments of your opponents on an issue like this is just a terrible idea. Even if Ritchie should win that game (and to his credit he doesn’t), it invalidates the research that shows intelligence to be an important concept, which was the reason the book was written in the first place. Evidence is the only currency of science. Responding to emotional arguments by appealing to those emotions is to short-change yourself to intellectual bankruptcy.


That said, my overall view of this book is very positive. Although I disagree with how the author deals with critics, he is at least trying to push things in the right direction (towards what the evidence tells us). He also packs a lot of interesting information into just over 100 pages without making the text feel crammed; in fact the book is so clearly written it almost reads itself. And Ritchie is a great teacher who knows how to explain things to a wider audience without becoming too technical or dumbing it down. In short, I doubt you can find a smoother ride to basic literacy on the subject of intelligence than this.

The Sour Grapes of Pisa

November 28, 2013
Still standing.

Still standing.


The new Pisa 2012 will be released on Tuesday, which for those who are unfamiliar with it is a recurrent survey on the performance of schoolchildren from all over the world. The winners in this survey tend to be the same over the years: various Chinese populations (Shanghai, Hong Kong and Singapore), Finland, Canada, Australia, Japan and South Korea.

A high rank is generally interpreted as the result of a good policy and a low rank will usually create headlines demanding reforms.

The Pisa Hall of Shame

At the bottom of the order we find poor and often Muslim countries like Kyrgyzstan, Azerbaijan, Peru, Panama, Qatar and Albania. But besides rich countries at the top and poor at the bottom, there is also the phenomenon of over- and underachievers, poor countries whose children perform well and vice versa. This measure is more interesting since it indicates a failed education policy or other factors that may have been overlooked.

Some of the worst underachievers (excluding tax havens and small oil countries) are USA, UK, Austria, Germany, Denmark and Sweden. How do people in these countries respond to the results of the survey?

America: Self-Criticism and Fear of China

When commenting on the results American media have mainly been comparing themselves with China and been surprisingly self-critical, as for instance from Stacie Nevadomski in the Huff Post shows,

“The truth, the real news, is that there is no news here. These results should be no surprise. The long slide in American student performance relative to global peers has been a constant drumbeat, paralleling the domestic failures of our schools shown in Waiting for ‘Superman’.”

Or education secretary Arne Duncan,

“The findings, I have to admit, show that the United States needs to urgently accelerate student learning to try to remain competitive in the knowledge economy of the 21st century.”

James Fallows in The Atlantic agrees but adds that that Shanghai, the winner of the Pisa 2009, isn’t representative of the whole of China – which is correct; neither is Hong Kong or Singapore who also rank at the very top. These are all elite populations. America scored better against the other Chinese regions of Macao and Taiwan and it would probably do even better compared to all of China. Although those who are familiar with unpublished results from other parts of China claim they are very respectable.

Regardless of how well America compares to China, it’s still a fact that 13 countries score better than America and all have significantly lower GDP per capita. Maybe that would be a more constructive focus.

European Skepticism

A more disturbing reaction has come from some of the European underachievers. Recently, the largest newspaper in Sweden, Dagens Nyheter (Today’s News), has featured an article about the upcoming Pisa 2012, with the headline “Several Countries Cheated with School Results”, suggesting that countries like Italy, Slovenia and the United Arab Emirates has falsified their results. The article is based on an unpublished study by German and Canadian sociology professors Jörg Blasius and Victor Thiessen. “The result means that the credibility of the Pisa survey can be questioned,” says Blasius.

This story is also getting attention in Denmark, another underachiever, where one of the major papers, Berlingske Tidende has an article about it. The article includes other criticism as well, mainly that of Svend Kreiner, a statistics professor at the University of Copenhagen. Kreiner has analysed earlier results. He is critical of how a lot of questions are omitted for some countries but included for others. He claims the methods of scoring are so arbitrary Denmark could be ranked second or 42th depending on arbitrary tweaks in the evaluation. In the article, president of the Danish Teachers Association, Anders Bondo Christensen, says it’s time to scrap the survey altogether.

In the UK (also an underachiever), there is a similar discussion on the TES educational community. In an article, TES’s William Stewart writes,

“Politicians worldwide, such as England’s education secretary Michael Gove, have based their case for sweeping, controversial reforms on the fact that their countries’ Pisa rankings have “plummeted”. Meanwhile, top-ranked success stories such as Finland have become international bywords for educational excellence, with other ambitious countries queuing up to see how they have managed it.”


“But what if there are “serious problems” with the Pisa data? What if the statistical techniques used to compile it are “utterly wrong” and based on a ‘profound conceptual error’? Suppose the whole idea of being able to accurately rank such diverse education systems is ‘meaningless’, ‘madness’?”

Sour Grapes?

However, fact is the alleged cheating is only concerned with follow-up questions to principals that have been found to be largely identical in many cases. It doesn’t concern the performance of the schoolchildren. It hasn’t even been established if it is actual fraud designed to make the countries in question look better or if it’s just a matter of laziness or even the fact that some principals are heads of more than one school.

Also for Kreiner’s analysis, Pisa’s own statistician, Andreas Schleicher, questions it on grounds that Kreiner is using a very small part of the data in spite of having access to all of it. He also questions the methods Kreiner used and suggests that they our outdated. As a response to alleged cherry picking, Kreiner replies by accusing Pisa/Schleicher of doing similar things. To me, that sort of rhetoric doesn’t exactly increase his credibility.

It’s not easy for a non-expert to make any sense of this, but I have to say that there is something disconcerting with the fact that Svend Kreiner is being awarded a prize for his critique while no one in Danish press is asking the questions that Schleicher’s comment raises. Is everyone in Denmark so familiar with statistics that it’s a non-issue? And big headlines about cheating even though it hasn’t been established?

Alternative Explanations

Rather than blaming the statistics, there could be other things behind why some countries underachieve. The most obvious thing would be changes in national IQs.

The Pisa survey (and similar tests) correlates strongly to intelligence tests; so much in fact that it actually is an intelligence test although it’s rarely referred to as such. This explains a lot of the rank order, because we know that intelligence is highly heritable and resistant to external forces – like education policies. Smart people like the Chinese are going to rank at the top and less smart people like Ugandans are going to be somewhere at the bottom. This is also a reason to be skeptical of the European sour grapes skepticism I mentioned earlier. If there was something seriously wrong with the Pisa it wouldn’t correlate so much with similar tests.

But intelligence alone can’t explain under- and overachievers. If we look at the latest national IQ estimates, the underachievers score like this,

Austria 99, UK 99.1, USA 97.5, Germany 98.8, Denmark 97.2, Sweden 98.6,

and, the three overachievers score like this,

Finland 100.9, Estonia 99.7 and Poland 96.1.

There is not much difference; the averages for these groups are 98.4 and 98.9. But maybe this snapshot disguises a trend in which underachievers are on the way down and vice versa?


I would suggest that this is the case, and that the reason for this is immigration. East Asian countries don’t have much immigration to speak of, but in Europe there has been a varying influx of people in recent years, especially from Muslim countries. The national IQs in these countries are usually around 85 so Western countries that receive a lot of these immigrants should see a larger decline in national IQ averages than other countries. If we look at PEW’s survey of Muslims in Europe, we can make a comparison between over- and underachievers. The most striking overachievers are Estonia, Poland and Finland, countries that all have extremely small Muslim minorities making up 0.1, 0.1 and 0.8 percent of the population respectively. Compare that with the figures for the underachievers Austria 5.7, UK 4.6, Denmark 4.1, Germany 5.0 and Sweden 4.9. Many immigrants are very young children who will take the Pisa survey in years to come or are taking it now but have yet to become adults and have an effect on the economy. Since the Pisa survey is just an intelligence test for children they simply reflect the influx of young and low IQ people. Underachievers have a larger influx so they score worse than you’d expect from the current national IQs and wealth because the effects on these metrics will kick in some years in the future. And overachievers are just maintaining their national IQs and consequently rising in rank since the rank order is relative.

So the way to improve the scores is not to reform the education system but to change the immigration policy.

So, Any Bets for Tuesday?

If I was to guess I would base it solely on national IQs, immigration and introversion scores, although that last one is a bit speculative. This would lead me to the safe bet that East Asians will stay at the top and no real low IQ countries will surprise anyone with a high rank. Judging by the immigration projections from PEW, Eastern Europe looks like it could be on the rise, or at least maintaining positions, although Russia and Bulgaria look problematic. The real winners here are probably small to medium sized countries that are relatively stable, like Estonia, Poland, Slovenia, Croatia and Hungary. Western Europe will show a downward trend, especially for countries that are increasing their share of the Muslim population from an already high level, like the UK, Austria, Sweden, Belgium and France.

But whatever happens, you can be certain that many people in the underachieving countries will keep blaming the test. Because changing your view on human nature and society is hard work and shooting the messenger is easy.

For more details about the Pisa survey, check out Steve Sailers blog which features several interesting posts on this subject.

The IQ Breaking Point – How Civilized Society is Maintained or Lost

September 24, 2013
West Virgina at IQ 96. Life just below the breaking point.

West Virgina at IQ 96. Life just below the breaking point.

It’s a well-known fact that intelligence corresponds to various kinds of life outcomes at the individual level, such as income, education, drug abuse, criminality etc. A little less known is the fact that national average IQs correspond to similar outcomes on the national level. This has been shown by among others psychologists Richard Lynn and Tatu Vanhanen, who have found staggering correlations between national IQ and things like health, education, income, crime, corruption, democracy.  To give you a rough idea, here are some of the findings,

Educational measures like TIMSS and PISA correlate 0.79-0.92

Number of scientists and engineers correlate 0.61

Measures of  per capita national income (GDP, GNP, GNI) correlate 0.51-0.89

Poverty and unemployment: -0.63 and -0.76 respectively

Crime in the form of homicide, assault and rape: -0.21 to -0.82 with distinctly higher correlations for the more accurate measure of homicide

Corruption: -0.27 to -0.68, all but one study above -0.54

Democracy: 20 of 22 measures show correlations around 0.60

Life expectancy: 0.51-0.82, expect for one study that found a negative correlation (possibly a typo)

Anyway, you get the picture. All the basic requirements for modern civilization – democracy, education, wealth, health and (lack of) crime and corruption – are strongly related to national IQs.

IQ 97: The Breaking Point

Seeing these correlations, it’s easy to assume that national IQ averages would correspond to specific degrees of development – that South Korea with an IQ of 107 would be much more civilized than Australia at 98, which in turn would be fairly similar to Russia or some other country at 97. But looking at the stats this is far from the case. Instead it seems like there is a point, somewhere around 97, above which a modern civilization can be maintained and below which things abruptly begin to fall apart. To illustrate this I’ll review some of the correlations mentioned above.

GDP (PPP) Per Capita

You can’t have civilization without money. It pays for education, healthcare, police etc. If we use the national IQs from, who appear to have the updated version of Lynn and Vanhanen’s data set (correct me if I’m wrong), and compare them with the GDP/PPP that takes local purchase power into account, we find clear support for the idea of a breaking point at 97 or thereabout. If we exclude oil nations, the top 20 with populations over one million, according to Wikipedia/IMF are,

Singapore, Hong Kong, USA, Switzerland, Canada, Australia, Austria, Netherlands, Ireland, Sweden, Germany, Taiwan, Belgium, Denmark, UK, Finland, Japan, France, Israel and South Korea.

In these top 20, there are nine nations in the 98-99 range, but only two countries below 98 – Israel and Ireland. Both can be partly explained by the fact that they receive plenty of financial aid from USA and the EU respectively. And it’s unlikely that Ireland will stay in the top 20 given its huge public debt and very high unemployment.

And if we look at more “normal” countries with IQs below 98, those without oil or rich friends, we find Slovenia with an IQ of 96 at 24th place, then Cyprus with an IQ of 91 at 26th, and Greece with an IQ of 92 at 27th. And Greece may well have lost this spot as I write this. So at 98 there are plenty of wealthy countries, but at 97 it suddenly seems to evaporate. And this isn’t just about money; if we turn to corruption we find a very similar picture.


According to the Corruptions Perceptions Index (CPI), the top 20 countries (again with a population of over one million) most free of corruption are,

Denmark, Finland, New Zealand, Sweden, Singapore, Switzerland, Australia, Norway, Canada, Netherlands, Germany, Hong Kong, Belgium, Japan, UK, US, Chile, Uruguay, France, Austria and Ireland.

Strictly speaking this is 21 nations since Austria and Ireland share the 20th spot and it seemed a bit random to exclude the one or the other. Anyway, we find 10 countries in the 98-99 range – including the top 4 and 6 in the top 10. The only three countries below 98 are Ireland (see above), Chile with an IQ of 90 and Uruguay with an IQ of 96. Again we see how everything is fine at 98, but at 97 and below things go south.


Turning to crime, so to speak, we find the top 20 countries with the lowest homicide rates (and more than one million inhabitants) according to Wikipedia/UNODC are,

Singapore, Hong Kong, Japan, Bahrain, Norway, Austria, Oman, Slovenia, Switzerland, United Arab Emirates, Spain, Germany, Qatar, Denmark, Italy, New Zealand, China, Saudi Arabia, Sweden, Australia.

This clearly breaks the pattern since we have five nations in the 98-99 range and just as many low-IQ nations, all from the Arab world. However, if we are looking for a point at which modern civilization begins to crumble, then we shouldn’t look at dictatorships at all. They can keep the murder rate low with social control and oppression, but at in doing so they disqualify themselves as candidates for civilized societies. So if we limit our sample to at least somewhat civilized countries we get a different picture. This is of course a rather subjective method but I think we can all agree that the countries above can’t be a part of it. I have included Hong Kong but excluded China so that’s where I draw the admittedly somewhat arbitrary line. The top 20 at least moderately civilized countries with the lowest homicide rates then become,

Singapore, Hong Kong, Japan, Norway, Austria, Slovenia, Switzerland, Spain, Germany, Denmark, Italy, New Zealand, Sweden, Australia, Poland, France, Netherlands, Ireland, UK, Portugal and Serbia (IQ 89).

Again, this became 21 countries because the two last share the 20th place. We find nine nations in the range 98-99 and four countries below that. The anomaly here is Slovenia at 6th place, a country that was also a mild anomaly with 24th on the GDP per capita list. But overall, this confirms the previous findings in that there are plenty nations in the 98-99 range but at 97 or less they are few and nowhere near the top of the list.

Indeed looking at where the sub-98 countries are on these lists we find that they made places 9 and 18 on the GDP list; 17, 18 and 20 on the corruption list and 6, 18, 20, 20 on the homicide list. So they are not only few but mainly at the bottom.


Finally, let’s have a look at the Economist Democracy Index for 2012. The top 20 nations with more than a million people are as follows,

Norway, Sweden, Denmark, New Zealand, Australia, Switzerland, Canada, Finland, Netherlands, Austria, Ireland, Germany, UK, Czech Republic, Uruguay, Mauritius, South Korea, USA, Costa Rica and Japan.

As you might expect by now, around half of these, nine, are in the 98-99 range whereas only four are below that. Again, Ireland is breaking the pattern, as are Uruguay, Mauritius and Costa Rica with IQs of 90 and 89 respectively. We also find that four of the top five have 98 IQs whereas those below this level are at 11, 15, 16 and 19.

An Index of Civilization

So what happens if we add these measures up? I did this by scoring point in reversed rank order starting from 100 for each measure to create an civilization index. A statistician can probably come up with something better, but it will give a rough idea of the overall picture. The chart below shows the result,


As expected, there is a general pattern of higher degrees of civilization as intelligence increases. But the most civilized countries are all in a cluster with IQs between 98 and 101. Below 98 the level drops dramatically as can be seen by the lack of dots in the upper left part of the chart. The only distinct anomaly left is Ireland which scores 360 points for the 12th spot and, less striking, Slovenia at 20th with 335. Or, given what I’ve mentioned about the Irish economy, it may be Slovenia that is the more genuine anomaly here – clearly not as horrible as it’s portrayed in the Hostel movies. At any rate, combining these factors eliminates anomalies and further strengthens the support for an idea of a breaking point at approximately 97.


I haven’t found any official statistics for state-level IQs in America. There are however some estimates made by the Audacious Epigone, based on the NAEP scores, and educational measures are strongly correlated with IQs. He has also set the American average at 98 which matches the figures I’ve used above. If we exclude District of Columbia, which is common in these cases since it’s full of government money and temporary inhabitants, the top 20 GDP per capita (I haven’t found any PPP numbers), are as follows,

Delaware, Alaska, Connecticut, Wyoming, Massachusetts, New York, New Jersey, Virginia, Washington, Colorado, California, Maryland, Minnesota, Illinois, South Dakota, Nebraska, Hawaii, Iowa, North Dakota and Louisiana.

As in all the previous calculations, we find that states in the 98-99 make up roughly half of the sample, once more dominating the top positions – 1, 2, 4, 6, 8. Below this level we find only three states, California with an IQ of 95 at 11th position and Hawaii with an IQ of 96 at 17th and Louisiana with an IQ of 96 at 20th place. There may be some explanations for these anomalies although I’m not that familiar with American politics. But it seems clear that California is in at least as much trouble as Ireland.

Conclusions and Implications

I’m not going to say that every conceivable measure on every conceivable level will show this pattern, but overall I think we have to conclude the existence of an IQ breaking point somewhere close to 97, at which we see drastically different outcomes depending on whether a country is above or below this level. A country can of course still fail above this point, like Italy and most likely North Korea. But a national IQ above 97 represent a necessary, but not sufficient, condition for success.

One implication, if this turns out to be true, is that immigration could pose a serious threat to the West, especially those countries and regions that are closest to the breaking point. The sad part is that since everything is going so well at 98 they may dismiss this risk. This is especially true for those countries and states who are right at 98 and whose immigrants have the lowest IQs, for instance France or Texas. As for California that state has now clearly passed the breaking point, it will be interesting to see if they will break the pattern. I suspect they won’t, given that the few countries that do fairly well below 98 (Ireland, Slovenia, Uruguay etc) are all small and lacking in diversity, which is the opposite of California.

It’s fully possible that someone else already has noted this breaking point, but since I hadn’t heard of it before and it didn’t seem like common knowledge, I figured it was worth sharing. I have no idea why 97 would be a magic number; maybe it’s just something in the human condition. I’ll be updating this article whenever I find any relevant information on this.

The Corrupt Person – Just Like You and Me?

March 25, 2013

"We're all friends here."

It’s well-known that crime is related to personality. The so-called Dark Triad traits of Psychopathy, Machiavellianism and Narcissism are more common in criminals than in the rest of the population. Basically, these individuals are impulsive, manipulative, self-centered and callous. Now, corruption is a form of crime so it would make sense that it too related to personality, especially to those traits mentioned above.

Unfortunately, there are no individual measures of corruption. Most of this activity is hard to detect directly so it’s measured indirectly by asking people how corrupt they perceive their environment, like their nation for instance.  And such a measure, like the Corruption Perceptions Index (CPI ), can then be compared to national averages of personality traits. That should give at least a hint of if and the two are related.

The Data

I haven’t found any international studies on the Dark Triad, so I compared international personality data compiled by psychologist Richard Lynn (1995) using the Eysenck Personality Questionnaire (EPQ).  This measure has at least one scale, Psychoticism, that has been clearly related to crime. In spite of its name it is a trait very similar to Psychopathy which is common in the prison population. I compared the EPQ data with the global anti-corruption organization Transparency International’s CPI (2012). There are some flaws in that the comparison refers to different years, but things don’t seem to change that much in either personality or corruption so I don’t think it’s a big deal. And as you can see…


CPI on the y-axis and Psychoticism on the x-axis. Remember that CPI measures lack of corruption

CPI on the y-axis and Psychoticism on the x-axis. Remember that CPI measures lack of corruption


…it’s a miss! The CPI measures lack of corruption so the -0.13 means that the correlation is not contradicting the hypothesis but it’s way too low to make a case of. This only suggests that the corrupt person has a normal or slightly elevated level of Psychoticism. Let’s look at the two other traits of the EPQ, Extraversion and Neuroticism. Here are the scatter plots,

CPI on the y-axis and Extraversion on the x-axis.

CPI on the y-axis and Extraversion on the x-axis.


CPI on the y-axis and Neuroticism on the y-axis.

CPI on the y-axis and Neuroticism on the y-axis.


Both correlate stronger with corruption than Psychoticism does, although still not very impressive: -0.19 for Extraversion and -0.18 for Neuroticism. This indicates that the corrupt person is fairly normal. This makes sense from a statistical perspective. Few people would consider stealing a car or breaking into someone’s house. But lots of people will take and receive “gifts” to grease the wheels a little. If the corrupt person would be the same as the criminal then Psychopathy and other extreme personalities you see inside the prisons would be much more common in the general population. So it’s got to be a fairly common personality.


Then there is the matter of intelligence. There is hardly anyone who would contest that corruption and national averages of intelligence are inversely related. Looking at Lynn’s data this is very clear,

CPI on the y-axis and IQ on the x-axis.

CPI on the y-axis and IQ on the x-axis.


The correlation is -0.69 which is very respectable. A study from 2011 by economist Niklas Potrafke, also using data from Lynn and the CPI, found a 0.63 (using the inverse CPI). Clearly, intelligence is a much stronger factor, but a factor which is related to personality. In my data I found a -0.54 correlation between Extraversion and IQ.  Although there is no consensus on this, it seems like more studies today do find a negative correlation between Extraversion and intelligence on the individual level, although not by far as big as I found here using national averages. For instance, a recent study found a -0.2 correlation between Extraversion and vocabulary. Extraversion may be linked to corruption merely due to its link to low intelligence, but I suspect it is a contributing factor in its own right, more on that later.

So, based on these figures, who is he, the corrupt person? An Average Joe? The data from Lynn suggests that it might be a completely average person, or maybe someone who is a little more extraverted, emotionally unstable and…well psychopathic (it may not sound like it but it is a dimensional trait like the others).  But hardly anything that would strike anyone as out of the ordinary. His most conspicuous trait would be his low intelligence, and living in a country with a low average IQ even that would not be conspicuous to his fellow countrymen.

The Extraversion Hypothesis

That said, the EPQ is just one measure among many and the quality of data is no doubt increasing over time, so the picture will eventually grow clearer. The correlation with Extraversion remains intriguing and this traits relation to intelligence is still not clear. Corruption is most likely also situational which may account for some of the high corruption in Eastern Europe, which is still recovering from the collapse of communism. For Western Europe the Extraversion/corruption correlation is -0.31. So while, it’s clear that IQ is the major factor affecting corruption levels, it seems like Extraversion can have something to do with it as well.

The link to intelligence is of course interesting itself, since it is by no means evident why a country with a low IQ would be more corrupt. It’s easy to imagine a dishonest but intelligent person trying to beat the system with corruption, for instance. Potrafke suggests that intelligent people have  longer time perspectives so they realize that they win in the long run by not resorting to corruption. Personally, I don’t buy that explanation. Do people abstain from corruption because they’ve made some pragmatic calculation? No, I think it’s more visceral. Taking a bribe just doesn’t feel good. It’s a matter of shame. And those taking the bribes just don’t feel ashamed. Why not?

The Link to Tribalism

I would say they lack shame because of their tribalism. And I’m not just saying that because my previous post was about tribalism and it’s lingering in my head : ) It is a fact that the most tribal societies in the world can be found mainly in Africa and the Middle East. And this is where the IQ levels are the lowest and corruption the most spread.  Now, the highly tribal person will not look at the public good, he will look after the interests of his tribe. And if his society is made up by several such tribes – and they all are – then he will ignore the public good and side with his own. So he will have no qualms engaging in accts of corruption as long as it benefits his group. There is no shame in it because his “real” society is the tribe. Sure, he could help his tribe even more in the long run by co-operating, but tribalism dates back to a time when there was no such co-operation.

So tribalism can explain corruption, but it can also explain low intelligence. Tribalism means conforming to the group and not thinking for yourself. That alone should put a limit to the intellectual growth.  Tribal societies also show clear signs of inbreeding . Since they can’t trust foreigners, they marry their relatives, and that is a great way to decrease your IQ. So instead of assuming that low intelligence causes corruption, which intuitively makes little sense to me, tribalism can be the cause of both these factors.

And what does this have to do with Extraversion? As I mentioned in my previous post, tribalism should be viewed as a personality trait in its own right. But traits are rarely completely distinct from each other.  My suspicion is that the tribal person is more extraverted than the average. If your life is all about the group then you’re probably interacting with other group members a lot. This didn’t show up in the study I mentioned in the previous post, as some of you might remember. But that was just one study and the participants were all from America, a country with a fairly low level of corruption. It can be harder to detect there than in the more to the clan-based societies that actually show clear signs of inbreeding. (For more on inbreeding and its effect on society, check out hbd* chick.)

I’ll get back to this if I can find more data on inbreeding and extraversion. Lynns data do support this idea but there are just too few tribal countries in his sample. Who knows, this theory may even hold for some Western groups, like Christian conservatives.  I wouldn’t rule it out.

The Study on Intelligence and Religion That You Weren’t Supposed to Hear About

March 5, 2013
Yoda - the beautiful union of intelligence and spirituality (and possibly also dyslexia).

Yoda – the beautiful union of intelligence and spirituality (and possibly also dyslexia).

Numerous studies have consistently arrived at one and the same conclusion: religious people are less intelligent than atheists. So maybe we should accept this fact and move on. Nah, just kidding. On the contrary, when behavioural scientists all come up with the same result it’s time to get suspicious. The normal thing in this field is a variety of results.

So, now that we’re all duly suspicious, the next step is critical scrutiny. I’ll just look at some of the major studies in recent time, but it should give you an idea of the situation.


In 2008Danish psychologist Helmut Nyborg conducted a study that showed that atheists scored an average of 1.95 IQ points higher than agnostics, 3.82 points higher than liberal persuasions, and 5.89 IQ points higher than dogmatic persuasions. This may sound impressive but Nyborg’s sample was made up of children age 12-17. It is well known that both intelligence and personality are under much larger environmental influence during childhood than in adulthood. Nyborg himself noted that religion declines under this period but failed to see how this makes the study flawed. Whatever the environmental factor is – peer pressure, rebellion etc – it decreases with time. This sort of short-term environmental influence goes for intelligence as well. It becomes stable once you reach young adulthood. So young people make a horrible sample for making general conclusions of how religion and intelligence might be related.


The same year British psychologist Richard Lynn (together with Nyborg) conducted a similar study. He simply compared the national averages of intelligence and rates of disbelief in God in 137 nations, making up 95 percent of the world’s population. Lynn found a very high correlation of 0.6 between these two variables. While this design appears to give the final answer, it is in fact measuring widely different countries which makes it very problematic. On such problem is that if we look at the big picture most nations in the world have an IQ close to 100 and then we have the Muslim nations that average around 80-85. So a large part of Lynn’s findings is about Islam, not religion in general.  If we restrict this sample to Western nations the correlation drops to 0.42. Lynn also admits that the surveys on religious disbelief may have problems with low response rates, being representative of the population etc. It remains an open question how much further the correlation would drop if we could adjust for this factors but we can’t so it really isn’t more than guesswork.


The third major study in recent years was conducted by Japanese psychologist Satoshi Kanazawa, who of course corrected the persistent flaw of using children in his samples. Well, kind of. He used participants aged 18-28 to measure religiousness but then took the same participants IQs at age 12-17 so it’s not much of an improvement. His sample was also the 75 percent remains of an original sample which leaves the question of how representative it was open. Kanazawa also made another mistake in how he measured religiousness. Rather than using a multidimensional test to separate quality and quantity he merely had people answer how religious they were on a scale from 1 to 5.  A fundamentalist will no doubt claim to be “very religious” and score a 5. If his intelligence is low (and there is something to suggest this, more on that later on) then that would contribute to the relation between religion and IQ by suggesting that a non-fundamentalist is essentially the same kind of person but with a slightly weaker faith. There are various ways a person can be religious but Kanazawa suggests this is a matter of degrees and in doing so everyone gets to be stupid on behalf of the fundamentalist. Furthermore he uses a simple vocabulary test as a proxy for IQ. Given all these problems, Kanazawa finds that atheists average around 103 in IQ and the very religious at 97. With all the crap he has been pulling I suspect even his fans were a little disappointed with such a meagre result.

Gary J. Lewis?

Although these three studies have been very publicized and quoted, there was a study conducted by psychologist Gary J. Lewis and colleagues at the University of Edinburgh in 2011 that never got much attention. This study actually used an adult sample (mean age 48), measured several aspects of religion and featured a composite measure of intelligence. It did have some limitations in that the sample was mainly White and only concerned itself with Christianity. But it should provide a pretty good picture of the relation between Christianity and intelligence among White Americans.  An especially interesting feature was that it controlled for the personality trait Openness to experience, relevant to both intelligence and religiousness.  So what did they find? Well, they did actually find that religious people are less intelligent, but the results may still come as a surprise. Here is the gist of it from the article,

 The results indicated that intelligence is significantly negatively associated with five of the six measures of religious belief, confirming previous work (Bertsch & Pesta, 2009; Kanazawa, 2010; Lynn et al.,2009; Nyborg, 2009). Certainty about these findings is enhanced by the fact that, in the present study, these relationships to intelligence remained after we controlled for both openness and education, two potentially confounding factors. It should be noted, however, that the effect sizes were small for all associations with intelligence, the largest being the modest intelligence–fundamentalism link (β=−.13), with all other associations estimated at less than β=−.10.

Note the level of these correlations. It’s a well-known fact that variables of this kind always correlate with each other so small correlations are to be taken with a pinch of salt. Here is one take on correlation levels from David Buss & Randy Larsen’s textbook (which I highly recommend) Personality Psychology: Domains of Knowledge About Human Nature (2010),

Although what is considered large or small depends on many factors, social scientists have adopted a general convention. Correlations around .10 are considered small; those around .30 are considered medium; and those around .50 or greater are considered large (Cohen & Cohen, 1975).

So, four of six measures of religiousness showed less than small correlations, a level you might call negligible. Spirituality was unrelated to intelligence, and, perhaps most surprising, fundamentalism (of the Christian variety that is) showed only a small correlation of -0.13.

We Are All Stupid in Our Own Way (Except Me)

Now, the higher quality of this study means that the correlation can be taken more seriously. But at the same time the result indicate that not even the fundamentalists are very unintelligent. This may seem puzzling but fundamentalists are mainly considered stupid because the deviate from the norm.  Consider for instance the mainstream delusions of Optimist Bias. This refers to how ordinary people have an optimism which goes against common sense. Typically the majority of all people believe that they have a lower than average risk of becoming alcohol dependent, catch an STD or have a heart attack. This rosy outlook is of course mathematically impossible but those who engage in this sort of thinking are not in general considered stupid, most likely because they are in majority.

And What About Openness?

I almost forgot the interesting trait known as openness which is known to be related to intelligence as well as a liberal attitude. It was actually slightly related to two measures of religiousness, spirituality and mindfulness, while unrelated to the others, with the exception of fundamentalism which it was slightly inversely linked to (-0.12) – which is pretty much what you’d expect. Another interesting finding is that fundamentalism was unrelated to both sex and gender, contradicting the notion of this person as a middle-aged or older man.

Hopefully, there will be more high-quality studies like this one to put the religious-people-are-so-stupid research to rest. The interactions of intelligence, religiousness and personality are very interesting and deserve a better fate than to be skewed and dumbed down for ideological purposes.

Why Intelligent People Are Healthier

November 29, 2012

“If you ask what is the single most important key to longevity, I would have to say it is avoiding worry, stress and tension. And if you didn’t ask me, I’d still have to say it.” George Burns (1896-1996)

The studies on intelligence and longevity all agree that those with high IQs live longer. One of these studies, the Swedish Conscript Study, is especially impressive since it includes practically all Swedish men born between 1950 and 1976 – making the number of participants just under one million. They all took an intelligence test which uses a nine grade scale. Those scoring 9 were 20 years later shown to have a 70 percent less risk of mortality than those scoring a 1.

This may sound like something obvious – people with high intelligence come from better homes and have been brought up by parents who give them more fruit and vegetables and less pizza and soft drinks. However, it was shown that adjusting for things like parental socioeconomic status as well as blood pressure, weight, physical illness at conscription, the risk of mortality for those with the highest intelligence was still reduced by 60 percent compared to those with the lowest intelligence. This is really worth noticing – social background makes up less than 10 percent of the reduced risk of mortality. This is partly explained by the fact that the men were in their 40s at the follow-up, and few die from cardiovascular disease at that age. But it’s still interesting to note that social background is such a little factor in overall mortality.

So while it’s known that intelligent people engage in health behaviors – eating vegetables, exercising, following the doctor’s orders when ill. It’s reasonable to suspect that a healthy lifestyle is the mediator between IQ and longevity, even though this lifestyle is probably more a matter of personal decision than upbringing. It accords well with the connection between IQ and death in cardiovascular disease, the biggest killer. But if we look at cancer, the second biggest killer, the connection with intelligence is weak or non-existent. For skin cancer it’s even inversed. How can that be?

I haven’t found any explanation for this paradox in the literature, but looking at the causes of these two killers it’s clear that cardiovascular disease is related to stress in a way that cancer is not. And stress is a lot about lack of control. It’s a well-known fact that those prone to stress, that is those having the trait neuroticism, have more heart disease. This idea is supported by another large study, called the Vietnam Experience Study, which looked at mortality of veterans and found that the more neurotic a veteran was the more a high intelligence would lower his mortality.

This suggests that a major part of why intelligence promotes health is in that it protects against the harmful effects of stress and thus against cardiovascular disease. How? It could be that they use their intelligence to cope with stressful events better. It may also be a matter of what some researchers call system integrity. A high intelligence, according to this theory, is an indication of a  generally more robust and well built organism that doesn’t break under pressure as easily as the average. Although this has been hard to prove some studies have found that reaction time, as a proxy for system integrity, account for most of the correlation between intelligence and mortality. It could of course also be a combination of stress handling ability and system integrity.

All of these interesting findings are found in the relatively new field of cognitive epidemiology. While it doesn’t disprove that eating lots of vegetables is good for you (it really is) it shows that this may be of less importance than most of us imagine compared to stress – our proneness to it in form of neuroticism, but perhaps even more important how we cope with it, both psychologically and in terms of biological hardiness.


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