Solving a Mystery for Satoshi Kanazawa

February 14, 2013

Over at the Big Think, psychologist Satoshi Kanazawa lists what he considers the unsolved mysteries of evolutionary psychology. One of these mysteries is the question of why people with many siblings have many children. According to Kanazawa this doesn’t make any evolutionary sense at all,

This is because people with many siblings have the option of investing in their younger siblings and increasing their reproductive success by doing so.  Humans are just as genetically related to their full siblings as they are to their own biological children; both share half their genes.

I think the solution to this mystery can be found in viewing extraversion and introversion as evolutionary strategies. There is plenty of research showing that extraverts are more sexually active than introverts. This would lead to them having more children (we’re dealing with an evolutionary time scale so we can ignore the effect of contraception), and since it’s also a highly inheritable trait it would make a person with many siblings more likely to have extraverted parents and for that reason he is likely to have inherited their extraversion and have many children himself.

But if so, why aren’t we all extraverts – if it’s enables us to spread our genes so well? To understand this I think we need to look at differences in this trait between people living in environments with varying degrees of resources. In good times with plenty of food available, extraverts would propagate and spread their genes by having many children but a relatively small parental investment. But sooner or later hard times would come and then the introverted strategy of few children and high parental investment would pay off. If there is a scarcity of food, giving all you can spare to one child rather than sharing it between 4-5 children becomes a winning strategy. That way, hard times would ensure that genes for introversion would survive.

Now, it’s a fact that different regions vary in resources. People who have originated in a cold climate, or at least in a region with long cold winters should, if this theory is correct, have a higher level of introversion than people from warmer regions. We are all familiar with the stereotypes of the introverted northerners and extraverted southerners. Is there any truth in it?

Looking at extraversion scores from Richard Lynn’s study (1995) of 36 (I omitted Iceland because it has a microscopic population) nations there is actually a bit of a pattern supporting the theory.

The average level of extraversion for all countries was 18.4. But those who originated in a cold climate (Nordic or Central Asian) averaged at 17.2, while those originating in a warm climate averaged at 20.0, with intermediary countries averaging at 17.9.

Extraversion scores by country and climatic origin.

Extraversion scores by country and climatic origin.

I’m probably not the first person to have this idea but since Kanazawa insists that it’s a mystery and this seems to be a plausible explanation, I thought I should share it.

Book Review: Quiet – The Power of Introverts in a World That Can’t Stop Talking (2012) by Susan Cain

April 25, 2013
The author Susan Cain doing her TED talk.

The author Susan Cain doing her TED talk.

A book just about introversion? At first blush, this may seem like a too narrow focus, but according to Cain, this trait is the “single most important aspect of personality.” She makes a good case by listing the various things in life that are linked to the dichotomy of Introversion/Extraversion – choice of friends, career and education, exercise, adultery, risk-taking, delayed gratification, to mention a few.

Why America Became Extraverted

But in spite the many qualities inherent in the introverted mind, American society is still biased in favor of Extraversion, Cain argues. Already in school, the outgoing jocks and cheerleaders are popular while introverts go under labels like nerds or weirdoes, outcasts that most kids avoid. The same attitude can be found among adults, although usually expressed less bluntly. Studies show that talkative people rate as smarter, better-looking, and more interesting than the rest. This bias has even been prominent in psychology and psychiatry where introversion often has been viewed as dysfunctional or outright pathological. Adler is perhaps the best example of the academic bias (in his terminology introverts are called the Avoiding type and extraverts the Socially Useful type).

But things weren’t always like this. Cain points to what historian Warren Susman has called the transition from the Culture of Character to the Culture of Personality that took place in America in the early 1900s. This change was supposedly brought on by the industrialization and urbanization. The mass market and city life meant that you had to be able to get along with strangers in a way you never had to when living in a village or a small town. To illustrate the change, Cain presents Susman’s findings on word frequencies in self-help books and advice manuals of earlier times. In the 1800s the words that were most frequent were, Citizenship, Duty, Work, Honor, Integrity and similar. In the early 1900s these words were gradually replaced with others like Magnetic, Fascinating, Stunning, Attractive, Glowing, Dominant, Forceful and so on.

While this shift is interesting, I remain skeptical to the idea that external forces brought on such a dramatic shift in national personality. Given the how heritable personality traits are, and especially how little shared environment means, it seems more likely that this shift was due to an influx of extraverts. The early settlers were Puritans and others who came to practice their religion in peace, and they came from Northwest Europe. This no doubt was a more introverted group than the European average. When large scale immigration resumed around 1830 it wasn’t so much people fleeing religious persecution; it was people who had heard stories about the land of opportunity, and a lot of them came from Southern Europe. This demographic change seems to provide a better explanation to the emerging Culture of Personality, which perhaps more appropriately should be called the Culture of Perception.

The American Business Culture

When you compare America with Europe or the rest of the world, it’s tempting to view extraversion as an important factor in how America became so successful. Cain, however, rejects this idea. She visits Harvard Business School which is obsessed with social activities and perception – “good luck finding an introvert here” one student told her. But in real life, you’ll find loads of successful introverted CEOs, like Bill Gates, Brenda Barnes and many others. Studies linking leadership to extraversion are based on modest correlations and, more damaging, leadership is rated on impression rather than results. The personality of a good leader, Cain says, depends more on the situation. According to result-based studies, introverted leaders are good at handling active employees, putting their ideas to use, while extraverted leaders are better at inspiring passive employees, rallying the troops.

But in the business culture these insights are not taken to heart, most likely because the business world is full of extraverted salespeople who have been told and want to believe that their social skills will bring them to the top. This culture, according to the author, is irrational and destructive in that it is based on faith rather than facts. A typical example is the open office plan, which research show is linked to low productivity, high blood pressure and conflicts in the workplace – but it’s still popular because it promotes the extraverted ideal.

Cain even claims that the current Great Recession we are in right now is largely due to those pesky extraverts. That people who try to warn about potential dangers are seen as weak and ungrateful. She quotes from Kurt Eichenwald’s book Conspiracy of Fools about how when in 2001, Vincent Kaminski, a managing director of Enron, just before the bankruptcy, tried to warn about the problems his company was in and what kind of feedback he received,

There have been some complaints, Vince, that you’re not helping people to do transactions,” the president of Enron told him, according to Conspiracy of Fools, a book about the Enron scandal. “Instead, you’re spending all your time acting like cops. We don’t need cops, Vince.”

And a more general quote directly from Kaminski,

“Many times I have been sitting across the table from an energy trader and I would say, ‘Your portfolio will implode if this specific situation happens.’ And the trader would start yelling at me and telling me I’m an idiot, that such a situation would never happen. The problem is that, on one side, you have a rainmaker who is making lots of money for the company and is treated like a superstar, and on the other side you have an introverted nerd. So who do you think wins?”

I think this part of the book is very interesting, and alarming since we know that this culture is alive and well, eagerly waiting for new opportunities with little concern for the risks involved. You have to wonder if maybe places like Harvard Business School should have a quota for introverts. Not to say that introverts are better at this game – America is a great example of entrepreneurship – but it’s not the 1950s anymore, today’s world is complicated and more caution, reflection and analysis is needed.

The Introverted Ideal

It’s understandable that an introvert living in America feels unappreciated and may want to compensate for this in some ways. But reading this book it’s hard not to feel that Cain is replacing the extraverted bias with an introverted one instead. She constantly talks about the virtues of Introversion. How it’s linked to intellectual and artistic achievements, empathy, integrity, conscientiousness, persistence and so forth. Extraverts, on the other hand are generally described as simple folk who are full of energy but without any judgment or sophistication. No, she doesn’t say that but that’s what it sounds like. The title of the book alone gives you a hint of this: extraverts are the ones who can’t stop talking.

Yes, there is a bias against introverts, and yes we should do something about that. But using that as a cover for unbridled self-glorification is not an improvement.

The Biology of Introversion

More interesting is Cain’s foray into the biological and evolutionary roots of Introversion. Like me, she prescribes to the optimal arousal theory which states that variation on this trait is a matter of sensitivity. An introvert is more easily aroused and will for that reason interact with their environment in a way that keeps stimuli at a low level – staying indoors, having just a few friends they know well etc. But what kind of stimuli are we talking about? Psychologist Hans Eysenck was the first to answer this. He claimed that it was a difference in the Ascending Reticular Activating System (ARAS) that made some into introverts and other extraverts. Others, like Jerome Kagan has found a correlation between the Fight-or-Flight response and this trait, although since this is an emotional response others have pointed out that this is more related to Neuroticism. Personally, I think a sensitive ARAS could trigger the fight-or-flight response more easily making this response and indirect measure of introversion/extraversion. Then there is the theory of Reward Sensitivity, the idea that extraverts are more rewarded by stimuli. This theory would essentially make Extraversion the same thing as Sensation Seeking – a trait of thrill-seeking and hedonism.

The author presents a lot of interesting research on this although it feels like they are all finding things that relate to this trait without being able to pinpoint it. Introversion is not fearfulness or aggressiveness as measured by the Figh-or-Flight response, and extraversion is not hedonism either – there are plenty of fearful extraverts and hedonistic introverts. The nature of this trait must be something else. I think Eysenck was right on the money with his ARAS theory – at heart it is a simple matter of attention and wakefulness, although all these system appear to interact in complicated ways.


As for the evolutionary reason for the Extraversion/Introversion trait, Cain mentions one theory by psychologist Kenneth Olson, who claims that Extraversion is the mark of the migrant, the more fearless person. This, Cain (and presumably Olson) mean, would explain why White people are more extraverted than Blacks or Asians. I can buy that Whites score higher on Extraversion than Asians, but are Africans and their descendants in America and elsewhere really that quiet and reclusive? Are African-American kids bullied in the school yard for being nerdy or socially inept and less cool than the other kids? Perhaps the Big Five, a problematic measure for sure, is to blame, or maybe it’s the incompatibility of cultures, but something is off here.

Still, the difference between America and Europe could well be that those who migrated were more extraverted, more sensation seeking and less fearful than those that stayed behind. But generally speaking I think the theory that evolution favored extraverts in a warmer climate and introverts in a cooler climate makes more sense. Cain practically admits that something like this could be a possibility when she mentions Kagan’s impression that high-reactive children (statistically related to Introversion) tend to have blue eyes more often than low-reactive children. Sadly there is hardly any research on this at all, so there is no way to know for sure. But kudos to Cain (and Kagan) for even talking about such “dangerous” notions.

Cain goes on to present various evolutionary theories. Like the simple but sensible idea that introverts add a bit of caution necessary for the group to survive. A purely extroverted group would crash like Wall Street – but with no one to bail them out.  Or Jung’s idea that Extraversion represents a strategy of high fertility and high mortality and vice versa. This would be in line with the climatic theory but it also fits with the idea that extraverts are pastoralists who are fighting to protect their cattle and most likely stealing other people’s cattle. Introverts would instead be the agriculturalists who will expose themselves to less risk and have fewer children and think more ahead. Cain mentions an interesting study about a gene variant linked to the trait Novelty Seeking, which correlates to both Extraversion and Sensation Seeking. Among Kenyan pastoralists with this variant were found to be better nourished than Kenyan farmers with the same variant. This may lend evidence to the idea that Extraversion is an adaption to a riskier and more improvised way of living. (This is also relevant to my previous post about the trait of Tribalism.)

A Yay or a Nay?

I have mixed feelings about this book. Cain’s idea of introverts as an oppressed minority, although partly true, feels a bit silly. As an introvert I object to her idea that we are “like women in man’s world.” Women are still oppressed and victimized in numerous ways whereas introverts can become both rich and powerful in any culture without anyone objecting to it.

That aside, she does write well, and although theoretically confusing, this book offers a lot of interesting facts, and she even dares to touch on some sensitive issues. So all things considered, it’s a yay.

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.

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