Are the Norwegians really the most extraverted people on Earth?

Norwegians are not so different from Finns, who are not known to be especially extraverted. Because of that I was a bit puzzled after reading results of cross-cultural studies in personality traits, like here by Jüri Allik (2005)

http://psych.ut.ee/~jyri/en/Allik_JPD2005.pdf

Figure 2 in

http://sys130.psych.ut.ee/~jyri/en/Allik%26McCrae_JCCP2004.pdf

shows that the Norwegians and Swiss are the most extraverted of all studied people while for instance the Portuguese and Spanish are introverted. The 2004 study by David P. Schmitt et al

http://journals.sagepub.com/doi/pdf/10.1177/0022022106297299

has also a Finnish sample, 32 men and 90 women, general community members. The scores showed that they were just as extraverted as Western Europeans.

The finding that Africans are the most conscientious people and East Asians the least was also mildly surprising. I tried to find a methodological error in Schmitt’s study by looking at the Finnish sample as I think I know those people rather well. There was one issue: according to the protocol they asked at least 100 male and 100 female volunteers, but from Finland they got only 32 and 90 answers. I personally never volunteer for any questionnaire, nor would I return the form if given one. It may be the same for many introverted Finns and it might bias the Finnish results, as would the uneven gender split.

Another reason could be that the terms in BFF are not what I expect them to be. If we talk about extraversion and introversion I have from somewhere read that introversion means that being in the company of people exhausts your energy while extroverts gain energy. In Schmitt’s Big Five Inventory extraversion is measured by traits such as active, assertive, talkative and so on. I do not see what losing or gaining energy has to do with being active and assertive, or shy for that matter, I would even question talkativeness. In my opinion introversion is an ability to stand loneliness and that causes the difficulty of tolerating too much company. It has nothing to do with being active, assertive or talkative. Extroverts just go nuts if left alone in the middle of a forest for a week or so.

Yet I do not think this is the main reason. I made an on-line self-test with one BFF questionnaire. It was not the Big Five Inventory that Schmitt used in the above mentioned paper (Table 3), but somewhat similar. I got the results I expected, high on Openness and Conscientiousness, low on Neuroticism, Extraversion and Agreeableness. It seems that the questionnaires measure correctly and the explanation for the curious results may be an unrepresentative test group. Women are representative of only one half of the population, and when these Finns get older they become more typically Finnish.

I also read this 2008 paper by Steven J. Heine et al

https://www2.psych.ubc.ca/~ara/Manuscripts/HeineBuchNorenz_2008.pdf

which confirms that national stereotypes agree with objective measures of a trait better than self-filled or peer filled questionnaires. The stereotypes matched evaluations of outside experts and therefore are not prejudices but valid ways of characterizing some aspects of national cultures.

In some way these self-questionnaires must be correct and national stereotypes are also correct, and yet there cannot be any real contradiction. Maybe it is true that people do not differ as much as the national stereotype would imply. After communism fell Eastern Europe looks much neater. That does not mean any genetic change in the personality traits of the people. It is just a change of norms in the society. There is a norm how to relate to other people in Northern Europe and that explains much, but not all, of why some nations are experienced as introverted or extraverted.

Could be, but I still believe there is a genetic aspect to introversion and the following 2017 study by Petri Kajonius and Erik Mac Giolla

http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0179646

did find Finns a bit more introverted (but maybe unexpectedly also remarkably low in Conscientiousness)

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2775052/

Finns aside, there were some results from these cross-cultural BFF studies that point out to differences between peoples. East Asians were lower on Openness and higher in Neuroticism. Europeans were higher in Extraversion and Openness to Experience and lower in Agreeableness. This can be a cultural difference between individualism and communality, but it could have a genetic basis.

As Robert R. McCrae’s paper (from 2002)

https://scholarworks.gvsu.edu/cgi/viewcontent.cgi?article=1038&context=orpc

explains, cross-cultural studies are yet to be interpreted, but gender and age differences in personality traits have been well demonstrated. Both have a biological basis, for gender differences it is genetic and follows traditional role models for males and females in primates.

One of these gender differences is Openness for ideas, which is stronger in men. This trait is positively correlated with IQ and associated with analytical thinking and scientific enquiry. Assuming that it has a genetic basis, it is natural to look for genes for it from the X chromosome, where males have recessive alleles expressed while females express only homozygotic alleles. Of course, most sex differences are caused by hormones and probably it would be more reasonable to think of autosomal genes, which are activated by sex hormones, but let us think of X-related genes.

Openness is high in people with European origins and in South America, where the people have a partial Amerind ancestry. There is a genetic relatedness between Europeans and Amerinds, demonstrated by ancient DNA and shown by the closeness of Y-DNA haplogroups R and Q. According to Schmitt’s paper South Asians and Oceanians have as high Openness as Europeans while Africans have lower. East Asians are the lowest in Openness. This may fit to the hypothesis that this trait was born in the Indus valley some 40,000 years ago after East Asians had separated before ancestors of present Europeans moved to Europe, but it may also be so that East Asians are low on Openness for cultural reasons and the trait was born in the same place around 50,000 years ago, before East Asians separated from the second migration out of Africa (or the second part of the only migration, the one with Y-DNA haplogroup K).

If the trait is in the X chromosome, Y-DNA is connected with it only through association with the X chromosome. Thus, while Uralic Y-DNA N is related to the East Asian Y-DNA O, this does not imply that peoples with these majority Y-DNA haplogroups should be close in X chromosomes. E.g., most female lineages of Finns are European, thus Openness scores of Finns are European, not East Asian. As X spends twice as much time in females as in males, we have to look at the females of the population to find the correct relatedness. The mtDNA of Amerinds includes both European and Asian haplogroups, which may match with higher Openness, if the reason is in the X chromosome.

The traits Agreeableness and Conscientiousness differ between North Americans and Europeans quite much though genetically these populations are similar. Probably genetic reasons cannot explain the differences. Extroversion separates only East Asians from the rest.

Let us first concentrate on Europe. The proposed scenario is that there appeared genes for Openness to ideas promoting an investigative mind. It led to behavior that increased IQ by selection in hunter-gatherer groups. That is, personality traits do not directly affect IQ, but they can lead to changes in the IQ.

These hunter-gatherers created agriculture, which increased the population. In a higher population there are more mutations. These mutations are mostly harmful and decrease IQ, but some are advantageous. As the population in the Middle East and Southern Europe has practiced agriculture longer than Northern Europe, we can expect a higher IQ in the North. The advantageous gene alleles influencing IQ would have improved verbal IQ. This is because it is needed in communication with people while Northern hunter-gatherers mostly needed spatio-visual IQ. A special profession, which requires high verbal IQ, is trade: historically it includes cheating others, a negative kind of intelligence.

Small populations are to some extent inbred, which decreases IQ. Thus, the Northern populations were inbred after agriculture was adopted and as a result the IQ was depressed until the technological level made it possible to move to a city. This led to a recent increase of IQ, which is seen as the Flynn effect. The effect would have stopped when European populations were no longer inbred, but currently there is an inflow of genes from other areas and it reverses the Flynn effect to the Lynn effect: as these other areas have lower average IQs, immigration will lead to a lower IQ in Europe.

Next we should look at East Asians. They have very different BFF scores from other people. They are very high on Neuroticism. Neuroticism is lowest on Africans and thus can be a new trait. East Asians are low in Extroversion, Openness, Conscientiousness and Agreeableness. East Asians are not lazy, thus low Conscientiousness must be a cultural way of answering to the questionnaires. These answers may describe a different culture, which has been called collective to contrast it with European individualism. The scores for the personality traits suggest a high stress and an effort to do your best.  Such a culture could result to higher IQ and lower inventiveness without any genetic component, but there is a genetic component associated with East Asian higher IQ shown by an IQ profile which is skewed towards spatio-visual IQ.

The fundamental component in this genetic basis may be introversion. Introversion is much more common with very high IQ people, thus it is in some way connected with IQ. It is the most hereditary of all personality traits. (And despite what the BFF studies may try to show, it is not true that Northern Europeans are just as extraverted as Southern Europeans. Introversion is genetic and not so much changeable.) Introversion was a good adaptation in cold climate when populations were sparse and you had to tolerate being alone. In the heavily populated East Asia introverts must feel highly stressed, which may explain the East Asian scores in the other personality traits.

Introversion then would be another genetic IQ-promoting trait in addition to Openness. Introversion is not gender-biased. Thus, it is likely to be determined by autosomal genes. This trait may have been inherited from Neanderthals. Introversion itself does not raise or decrease IQ, but it promotes behavior which increases IQ, such as reading and thinking instead of spending time with people.

What could be testable in this scenario?

One could test if the Flynn effect can be explained by less inbreeding.

One may be able to test if a larger population decreases IQ. The places where agriculture has been long practiced are known. It is rather curious that higher IQs should be found in the North where people were hunter-gatherers longest.

The profile difference of verbal and spatio-visual IQ may be connected with trade versus hunting and gathering. This may be testable.

It may be possible to find if there are any fixed X chromosome genes for Openness in some populations. Advantageous alleles for males in X get fixed quite easily.

A connection between introversion and spatio-visual IQ could be studied.

Maybe I will invent a way to make small calculations on these issues.