Saturday, April 13, 2013

Pathogen-stress theory

A Paris suburb, on the eve of the French Revolution. The shift to democracy and individualism began under conditions of high pathogen prevalence and long before modern sanitation (source)

Is stress from parasites a major cause of psychological differences among humans? Yes, if we are to believe a popular theory in evolutionary psychology. According to this theory, when people develop in a parasite-infested environment, they behave in a way that reduces their likelihood of infection. They become less curious, less exploratory, and less open to strangers. The result is a cultural system that is less conducive to learning, openness, and tolerance—in short, what we like to call progressive values.

[…] the predictions of the parasite-stress model are consistent with the marked increase in the liberalization of social values that began to occur in the West in the 1960s and 1970s (e.g., civil rights, women’s rights, gay and lesbian rights, anti-authoritarianism, etc.). In the West, but not outside of it, infectious-disease prevalence was reduced dramatically a generation or two earlier as a result of widespread availability of antibiotics, child vaccination programs, food- and water-safety practices, increased sanitation and vector control.

This theory is used to explain not only cultural differences over time, but also cultural differences over space, i.e., between different human populations:

The parasite-stress model of human sociality provides an evolutionarily informed explanation of why specific human populations inhabiting different parts of the planet (northern Europe versus southern Europe, for instance) are often described by different traits, different values, and different cultural norms.

[…] parasite prevalence also is expected to predict other forms of political liberalism. For example, democratization is accompanied by the liberation of women from the tradition of masculine social control, which manifests in an increase in women’s civil rights and political representation (Inglehart, 2003; Wejnert, 2005; Welzel, 2007). It follows from the parasite-stress model that this form of liberalism should be more pronounced within populations that have a relatively low prevalence of parasites. It is. Across many countries of the world, parasite prevalence correlates negatively with national indicators of gender equality (Thornhill et al., 2010)

Several objections come to mind. Liberalism goes back long before the 1960s. Think of the American and French revolutions. Think of the abolitionists, the chartists, and the suffragettes. These were genuine mass movements that caught the imagination of ordinary people, and not just the elites. Yet they occurred at a time when young men and women routinely died from pathogens under conditions like those of the developing world today. And those conditions persisted well into the 20th century. It really wasn’t until the interwar years that doctors began to cure more people than they killed.

The parasite-stress model has been re-examined by Hackman and Hruschka (2013) with respect to the United States. They confirm that pathogen prevalence correlates with collectivism, strength of family ties, homicide, child maltreatment, and religious commitment. These correlations, however, hold true only for sexually transmitted diseases. Non-STD infections show no correlation with the above behaviors. Moreover, the STD correlation may simply be a side effect of lifestyle choices. As the authors note: “A life history model can explain these ambiguous results by treating STDs as an outcome of faster life history strategies rather than a driver of behavioral adaptations.” Indeed, the data are best explained by two variables: early childbirth and race, i.e., non-Hispanic white American, Hispanic American, or black American:

Our two-component measure [early childbirth and race] showed that across race categories, teenage birth rates are predictive of three-generation households and proportion of the population living alone. We conclude that these findings are inconsistent with the PST [pathogen-stress theory], but fit well with an alternative model based on life history allocations. (Hackman and Hruschka, 2013)

Parasite-stress theory reverses cause and effect. Pathogens are less prevalent in those human populations that have integrated principles of modern hygiene into their lives. Those same populations have also adopted other aspects of behavioral modernity—pacifism, individualism, reduced importance of kinship, etc. More broadly speaking, the construction of freer, more open societies cannot happen without certain psychological predispositions: first, higher anger thresholds and less willingness to use violence as a means to settle personal disputes; second, a time orientation that allocates more resources to the future and fewer to the present. Evidently, if you’re more oriented to the future, you’ll avoid choices that may lead to illness and early death.

This point may seem obvious, yet it’s surprising how unobvious it seems to some people, especially those, like evolutionary psychologists, who should know better. How come? Keep in mind that elite approval is necessary for advancement in society, particularly for academics who work amidst offspring of the elite and who help legitimize the dominant social agenda. To gain acceptance for their own pet ideas, academics unconsciously, or consciously, sign on to the elite's agenda.

As Thornhill et al. (2010) note: “[…] public health initiatives are most likely to have additional consequences for societies (e.g., promotion of civil liberties and egalitarian value systems).” Here, the academic is no longer pretending to be a disinterested observer. The role is more like that of a cheerleader … or worse.


Barkow, J.H., Cosmides, L., & Tooby, J. (eds.) (1992). The Adapted Mind. Evolutionary Psychology and the Generation of Culture, New York, Oxford: Oxford University Press.

Hackman, J. and D. Hruschka. (2013). Fast life histories, not pathogens, account for state-level variation in homicide, child maltreatment, and family ties in the U.S., Evolution and Human Behavior, 34, 118-124.

Thornhill, R., C.L. Fincher, D.R. Murray, and M. Schaller. (2010).  Zoonotic and Non-Zoonotic Diseases in Relation to Human Personality and Societal Values: Support for the Parasite-Stress Model, Evolutionary Psychology, 8, 151-169.



Anonymous said...

European populations have higher Openness and Extraversion relative to the long-settled, high density societies of Asians and Indians. Assuming these personality scores mean anything at all, we should predict that people with higher O and X scores will be more socially adventurous and thus more prone to spreading and catching communicable diseases; in warm climates with dense populations having a long history of agrarian subsistence modes, diseases will exert a stronger selective pressure over the generations against both traits O and X than in the climate of Europe (particularly Scandinavia and Russia).

Do you have a better explanation for the high Openness and Extraversion of Europeans relative to Asians and Indians, Peter?

JayMan said...


"Do you have a better explanation for the high Openness and Extraversion of Europeans relative to Asians and Indians, Peter?"

See here:

the middle ages | hbd* chick

and here:

An HBD Summary of the Foundations of Modern Civilization | JayMan's Blog

JayMan said...

Also, I suggest starting here in general:

start here « hbd* chick

Sean said...

Parasites are less prevalent in those human populations that have lower testosterone, because it compromises immunity. Polygyny raises testosterone levels in a population, and results in more inbreeding. Immunity is compromised by inbreeding though lack of major histocompatibility complex diversity. Masculine social control is greatest in the most testosteronised (ie most polygynous populations). So, there are more parasites and more male domination of society where there is a higher average level of masculinity. Think Senegal as opposed to Denmark.

The affluent educated classes are the least testosteronised, and they are the most liberal. They are also more inclined to look after their health, thereby maintaining immune competence. The population of Vermont would have far fewer parasitic infections than the population of Alabama even if they were living in similar conditions.

kgry said...

@Anonymous commenter 1: To remove confounding ancestry-related variables, you would ideally contrast pairs of people who are closely comparable in ancestry but have significantly different depths of residence in high-density societies. This may be difficult to do (I would not contend that Mongols and Han Chinese, for instance, are related enough to qualify as one such pair). Maybe nomadic and sedentary Tibetans? In this case, though, population densities would be low enough on both sides that we don't hit the question dead-on.

kgry said...

The issue, of course, is that long-standing differences in lifestyle mode are easiest to find between genetically long-distinct (or differentially admixed) peoples, and that we might mistakenly attribute to population density/pathogen transmission risk attributes having their primary basis in something else entirely. (Same goes for traveling along a climatic gradient in a contiguous landmass, which often also takes you along an admixture cline.)

Maybe we can explore this, albeit in a coarse sense, by simply taking a look at personality differences between low-density pastoralists, low-density hunter-gatherers, high-density ("affluent") hunter-gatherers, low-density agriculturalists, and high-density agriculturalists sharing a large component of ancestry (in a general continent-level sense), with as many replicates of each class as we can get.

Do sufficient data even exist? There are no predominantly West Eurasian hunter-gatherers alive today (and the ones persisting today in Africa, South Asia, Siberia, and the Americas have generally been subjected to weird demographic constrictions and pushed to marginal environments, if not also having been subjected to substantial recent admixture with non-hgs), and probably the great bulk of the personality data are merely anecdotal.

But I think it'd worthwhile to take a look at East Eurasia or the Americas, using Australian aborigines as the outgroup.

Anonymous said...

European populations have higher Openness and Extraversion relative to the long-settled, high density societies of Asians and Indians.

Are all European populations characterized by high openness and extraversion? The people of Protestant European countries have traditionally been characterized as being stoic and introverted.

Anonymous said...

Are all European populations characterized by high openness and extraversion?

The people of Protestant European countries have traditionally been characterized as being stoic and introverted.

German types (and related types) tend to be serious (The German Seriousness), but that's a little distinct from them not being sociable and open minded.

It's quite possible to be serious and open and extraverted. We tend to associate the sensation seeking and novelty seeking parts of extraversion as the clearest part of the construct, but there are strong elements of simply being sociable and intellectually curious as well.

Anonymous I said...

@ Jayman: Er... I'm really more interested in what Peter Frost has to say on the matter, thanks.

@ Anonymous II & III: I interact pretty regularly with Germans, and I don't know that I'd describe Germans as being especially serious. And Germans do test as Open and Extraverted, like most Europeans. Of course, there's even more question about the cross-cultural generalizability of self-report personality data than IQ test scores. But when I compare any Western European group I've had contact with to most populations outside of Europe, I definitely think all Westerners really are more outgoing and nonconformist than stoic and introverted.

Anonymous said...

German types (and related types) tend to be serious (The German Seriousness), but that's a little distinct from them not being sociable and open minded.

Yes, I was thinking of Germans, who are traditionally stereotyped as being serious and introverted, but also other Protestant nations such as the Scottish (stereotyped as dour Calvinists), Scandinavians, etc.

Anonymous said...

I interact pretty regularly with Germans, and I don't know that I'd describe Germans as being especially serious.

I was thinking of traditional stereotypes and characterizations. Contemporary Europeans may be different. There is also the influence of American culture in contemporary Europe. I don't think you'll find traditional Scottish Calvinist types in Scotland anymore. Maybe there are remnants in Ulster, but even there I believe they're dying out.

But when I compare any Western European group I've had contact with to most populations outside of Europe, I definitely think all Westerners really are more outgoing and nonconformist than stoic and introverted.

Compared to, say, blacks?

Sean said...

'dense populations having a long history of agrarian subsistence modes' A better example than India or Korea would be Senegal (which happens to be the most polygynous country on earth): What's in your water??? Mine is full of parasites and magic potions.....

Nowhere has more parasites than west African countries like Senegal, but Africans are extroverted because of polgyny: Extraversion: a tool for mating success. "extraversion, defined as “pro-social behavior which reflects sociability, assertiveness, activity, dominance and positive emotions.” Men with above-medium extraversion were 40% more likely to have more than one wife than those with below-medium extraversion, after controlling for age. Furthermore, this personality trait correlated with higher testosterone levels. Such a linkage suggests that extraversion is part of the male toolkit for mating success in a high-polygyny environment."

Unravelling complex associations between testosterone and parasite infection in the wild."...endogenous testosterone in male gazelle was correlated with mating behaviour in terms of sexual signal intensity (horn size) and resource-holding potential (territoriality). We also showed that these same levels of testosterone were associated with immunity and parasite infection". In humans Testosterone Increases Susceptibility to parasitic infection.

"FITNESS cost of testosterone-induced increase in oxidative stress might be substantial....Physiological costs of testosterone can confer the honesty of sexual signalling "

Pathogen disgust predicts women’s preferences for masculinity in men’s voices, faces, and bodies

Cross-cultural variation in women's preferences for cues to sex- and stress-hormones in the male face "We found significant relationships between a measure of societal development (the United Nations human development index 2011) and preferences for cues to testosterone in the face, and the interaction between preferences for cues to testosterone and cortisol. We also found a significant relationship between preferences for cues to testosterone and a societal-level measure of parasite stress."

Anonymous said...

When Lewis and Clark came across the native Americans they were amazed that they let their women sleep with other men. I had always assumed this had to do with the lack of venereal diseases among native Americans and its prevalence in Europe mandating pre-marital celibacy and post-marital fidelity. Seems like a good explanation. (Of course, when they left, the native Americans were all infected by VD.)

Sean said...

Where the testosterone levels are high, because of polygyny, the population will have reduced immunocompetence. 'HOST susceptibility contributes to virulence. Once transmission occurs, the pathogen must establish an infection to continue. The more competent the host immune system, the less chance there is for the parasite to survive. ... For this reason virulence thrives in a community with prevalent immune dysfunction.'

Higher testosterone levels in a population lead to more testosterone mediated behavior which may increase the potential transmission of parasites.

"ACROSS societies, most polygyny, for a variety of reasons, is sororal: men marry sisters. In areas of high pathogen stress, however, polygyny tends to both more commom than in low-stress
areas, and also non-sororal. In addition, the capture of women for mating is more common than in low-stress areas. Men may profit genetically from this shift: their children will not be more numerous, but genetically more variable—an advantage in the face of pathogen stress (Low 1990). Here it is worth noting that, in several mammalian species, including humans, some male-female “matches” in the major histocompatibility comlex (MHC), result in improved offspring immunocompetence. That is, rather than a uniform preference for “good genes” in this highly polymorphic region, there may be mate preferences (by both males and females) for mates who will produce more heterozygous offspring."

To get wives from outside areas men go on woman stealing expeditions, which often involve fighting, dodging spears ect, things which extra testosterone is useful for.

Sean said...

Low second-to-fourth digit ratio predicts indiscriminate social suspicion, not improved trustworthiness detection.
"Our results suggest that early prenatal organizing effects of testosterone in the foetus might impair rather than boost economic outcomes, by promoting indiscriminate social suspicion"

Anonymous said...

I'm not so sure about the links to testosterone - it's not clear why this would be the case.

For example, higher facial masculinity shows positive correlations with health in males (this may not be the case for females, but at best that would balance).

e.g. and

One reason though why I would expect testosterone levels to correlate with reduced immune efficiency is that testosterone would be correlated with increased energy expenditure through increased size and activity (features which contrast the male and the female, as larger and more active and smaller and more inactive morphs of the same species, respectively). This is probably one reason why men are leaner than women, even when matched for body size and energy intake - they habitually use more energy and proteins, so there is less to store (and possibly also why eunuchs and women are relatively more long lived than men - less energy use, less dna and cell damage).

Increased size and activity means less free resources available for immune defence.

In situations where an increase in testosterone may occur with a corresponding increase in diet, then it may not compromise immune effectiveness, while in a more diet limited situation (assuming a normal environment rather than an obesogenic one where the problem is too much energy intake, rather than not enough) immune effectiveness may be compromised as a tradeoff.

Low second-to-fourth digit ratio predicts indiscriminate social suspicion, not improved trustworthiness detection.

Trust game players (n = 144) trusted less when they had lower 2D : 4D (high prenatal testosterone), but their ability to detect the strategy of other players was constant (and better than chance) across all levels of digit ratio suggests than low 2D : 4D may tend towards errors where subjects are not trusted when they should be, while high 2D : 4D may tend towards errors where subjects are trusted when they should not be.

It is not immediately obvious to me that either of these strategies (error in social suspicion rather than social trust) would lead to worse economic outcomes.

The useful variance here is in how effective the ability to detec the strategy of others is, which appears unrelated to T.

As an aside, testosterone levels apparently predict both male ingroup altruism and honesty (feeling that lying is cheap and unworthy).

Anonymous said...

time orientation that allocates more resources to the future and fewer to the present

Although, if you are allocating your broom to do sweep up mañana rather than today...

I think the thing here I'd like to point out (rather tangentially) is not to think of future vs present time orientation as a trade off continuum.

This is where if you look at Geert Hofstede's work, which adopts this continuum model, you might become confused.

Under Hofstede's model the Anglo and Western societies are present oriented while the Asian ones are future oriented.

And the thing with this is, if you look at future vs present as a tradeoff, this is indeed true.

But the modern Anglo societies are both more oriented towards more change and activity and available resources BOTH now AND in the future, than say many premodern societies.

And indeed, if they were not oriented towards change right now and in your lifetime, its difficult to see how they could have the attitude towards growth and progress that characterizes them. A society with no orientation to do anything in the present (no consumption, no demand, no experiencing, no growth right now) never gets anything done!

Anonymous said...

"I definitely think all Westerners really are more outgoing and nonconformist than stoic and introverted."

"Compared to, say, blacks?"

Black people in the west aren't nonconformist to black culture. They're nonconformist to white culture.

Anonymous said...

Black people in the west aren't nonconformist to black culture. They're nonconformist to white culture.

The same could be said for whites, no?

Blacks seem less stoic and introverted than whites.

Peter Fros_ said...


Openness and extraversion are qualities that develop in high-trust societies. Such societies develop where (a) the State imposes a monopoly on violence and pacifies day-to-day social relations; and (b) where lifelong kinship ties and reciprocal obligations give way to looser and more transient relationships between individuals, particularly within the framework of a market economy.

These two trends are interrelated. In fact, (b) is largely a consequence of (a). Both trends began about the year 1000 in Western Europe with the re-assertion of State power after the Dark Ages and with the active support of the Church. Both the State and the Church strove to pacify social relations, and this pacification made possible the emergence of more open and more individualistic societies.

Even within Western Europe, however, there are areas, like the border country between England and Scotland, where pacification remained incomplete. If you want to know what Western Europeans used to be like, look at the Scotch-Irish.

Why didn't this process take place elsewhere? East Asia was really the only other area where it started to happen. The process aborted, however, because pacification, particularly of the countryside was much less complete. Part of the reason was that religion in East Asia was much less actively involved in pacification. Another reason was that China's elites were of foreign origin from the 13th to 19th centuries and thus more indifferent to the welfare of the Chinese population.

Anonymous said...

Openness and extraversion are qualities that develop in high-trust societies.

We may be talking past each other and may have different definitions in mind for things like "introverted" and "extraverted".

By "introverted" I'm thinking of shy, retiring, quieter, less gregarious, etc. Based on encountering blacks, they do seem to come across as relatively less introverted than whites. The loud, talkative nature of blacks has been noted for centuries by European observers, presumably because it was a departure from European norms. I believe even Darwin himself remarked upon it as one the differences among human populations.

Anonymous said...

That's a common impression, but it doesn't actually come out in the Big 5 personality tests interestingly enough.

I think it may be because the differences are on subfacets. These are Warmth, Gregariousness, Assertiveness, Activity Level, Excitement-Seeking and Positive Emotions. Assertiveness and Excitement-Seeking might show higher trends among Black folks, but I do not get the impression that they necessarily show higher Warmth, higher Activity Level (are more industrious), have particularly high Positive Emotions and even Gregariousness seems like a bit of an odd one. Many Black people I have met seem to enjoy the opportunity to seek social attention, but can also be very cagey, sullen and withdrawn.

Big 5 factors do represent clusters of self descriptors which reliably do positively correlate in frequency, but there is room for subfactor difference.

Anonymous said...

From Social and Mental Traits of the Negro by Howard W. Odum:

"The Negro is essentially gregarious and loves companionship. He very naturally seeks companionship, whether it be of similar tastes and natures or not. This gregarious feeling is manifested naturally and continually."

From Life magazine in 1938:

"It must be remembered that the Negro is probably the most social and gregarious person in America. Nothing delights him more than a big lodge, with many a gold-braided official and many a high-sounding title. Lodge life is the most exciting part of the social doings of the great mass of American Negroes."

Drew said...

Exposure to UV Wavelengths in Sunlight Suppresses Immunity. To What Extent is UV-induced Vitamin D3 the Mediator Responsible?

Anonymous said...

"The same could be said for whites, no?"

I don't really know enough about the big 5 to know precisely what they measure.

I was just saying that in the context of a minority in a majority culture behavior from a member of the majority group which might be measured as non-conformist could simply be hostility to the majority culture when measured in the minority group.

Anonymous I said...

Thanks for your answer to my question, Pater! Something to think about, as always.

I do wonder, however, whether your model can cope with the situation in Northern Europe, which by all accounts was pretty uncivilized until quite late in the game. Shouldn't the Southern Europeans who lived under Roman law be more Open, Extraverted, pacifist, and otherwise civilized than Scandiavians? If anything, I'd say that the reverse is actually true.

Regarding the discussion by the other anonymous posters, I'd like to suggest that you take a look at the six-factor HEXACO model; Wikipedia has a decent article on it. Even better, if you can find it, try looking up this article (I'm trying to leave a link to it in my URL):

Michael C. Ashton, Kibeom Lee, Reinout E. de Vries, Joshua Hendrickse, and Marise Ph. Born (2012). The Maladaptive Personality Traits of the Personality Inventory for DSM-5 (PID-5) in Relation to the HEXACO Personality Factors and Schizotypy/Dissociation. Journal of Personality Disorders: Vol. 26, No. 5, pp. 641-659.

I believe that this 7-factor model discussed there (and in a few other articles in the same vein) has a shot at representing the first dimensionally complete personality space. We'll have to see how the research pans out!

Sean said...

"WE have also been finding structural brain deficits in violent offenders in the community. Such individuals with antisocial personality disorder have an 11% reduction in the volume of gray matter in the prefrontal cortex as assessed by structural MRI compared to control groups, together with reduced autonomic activity during a social stressor. The orbitofrontal cortex and middle frontal gyrus seem to be particularly compromised"

The lateral orbitofrontal cortex is where self control lives

Fetal Testosterone Influences Sexually Dimorphic Gray Matter in the Human Brain:-"gray matter volume in PT/PO and posterior lateral orbitofrontal cortex was greater in females compared to males and was negatively predicted by fetal testosterone."

Peter Frost said...


It's not so much civilization, as the construction of a high-trust environment where one can interact with people as individuals, and not as fellow clansmen and clanswomen.

Anonymous I said...

No, I understand; your idea is that when there is no need to fear strangers might attack, rob, or swindle a person, the genes which thrive under a clannish social system are no longer evolutionarily favored.

But for much of what elsewhere in Europe was known as the High Middle Ages, Scandinavia remained in a period of tribalistic war. Consider for instance the Poetic Eddas, dating to the last half of the 13th century, and described in as dwelling "on cruel and violent deeds with a grim stoicism that is unrelieved by any civilizing influences." Where Christian missionaries had gained a firm foothold elsewhere in Europe, Nordic religion continued to glorify warfare as the path to the afterlife, and blood Feuds between clans were common throughout Scandinavia. What all of this suggests is that, according to your model, Northern Europeans should today be more like older Europeans. But if anything, the reverse is observed.

I will add further that it is also unclear to me why a high-trust environment would select specifically for Extraversion and Openness. The "big men" you sometimes write about seem likely to be extroverted, while the sexually successful artisans and craftsmen of a high-trust society tend to invoke images of conscientiousness. Thus we might rather expect the denizens of highly civilized societies to become more conscientious and less extroverted, but this is not what is observed.

Still, there are always little details to be worked out in any theory. We'll have to see where it goes!

Sean said...

Unless you are a hereditary big man (clan cheif), trying to be a big man is an extremely high risk strategy. From what I know about the Scottish Highlands, commercialisation rapidly dissolved the clan allegiances, and it was a top down process.

Scandinavia hasn't the achievements one would expect of a particularly advanced population. It didn't have the first commercial state like England (and Holland). Nor did Scandinavia have a glut of inventors or creative intellectuals, like Scotland. In modern times Scandinavia has had a very socialistic welfare society.

English society has tended to laissez-faire. The English temperament is liberal and individualistic; ideal for success in a civil-commercial society. That comes through in the work of John Locke. He was a English philosopher of the pre capitalist age, but managed to invent Liberalism and English thought continued along those lines.

Anonymous said...

"But for much of what elsewhere in Europe was known as the High Middle Ages, Scandinavia remained in a period of tribalistic war... What all of this suggests is that, according to your model, Northern Europeans should today be more like older Europeans. But if anything, the reverse is observed."

I think it's right that if the model is correct it requires an explanation for the speed of the transformation and how the north overtook the south given the south's head start.

Anonymous said...

I will add further that it is also unclear to me why a high-trust environment would select specifically for Extraversion and Openness.

The model as I would understand it would -

A certain level of trust is necessary to make it worth the risk of socialising with people outside your immediate group i.e. people feel fairly confident they're not going to be scammed or exploited immediately.

Once there is the capability then social structure develops so social group membership is "fluid" and that inclusion or exclusion from any social group is negotiable. As such, stronger social skills in the form of extraversion are necessary, to be able to get into groups (because you still need social groups and you aren't just in a clan as a function of birth), to continually renegotiate group membership and to avoid being isolated.

Openness might be more useful to be able to appreciate new art, music and new status signalling beliefs, which would facilitate group membership.

Of course, even this is all true in Western societies, I think its pretty likely that other societies also have other forms of selection for extraversion - e.g. certain kinds of mating success would encourage a form of extraversion which may prioritize "dominance" - and some societies may recreate the Western social model within fairly large and free mixing tribal groups, while still having friction between tribal groups.

I think stuff like hbd chick's work makes Arab societies into poster children for tribalism, but the present day populations are all kinds of mixed compared to the likely pre-Arab period genotype, and mixing has gone on for some time. Cousin marriage may be fairly recent as a phenomenon.

Sean said...

Anons are being persnickety. They're ignoring the cyclical effect of an ethical system's influence on the character of a population; once a society adopts a peace-loving universalist ideology it inexorably eliminates warrior's genotypes; then is helpless in the face of mass migration. It happened to ancient Rome. The Roman Empire became meta-stable, and that metastablility presaged mass migration and the whole process going into reverse.

Anonymous I said...

I don't think we're ignoring anything. I realize it's difficult to sort out who is who, but I was the one who mentioned Scandinavia's late Christianization as representing a problem for Frost's model. To say Scandinavia is just a bunch of socialist go-nowheres ignores the fact that they are a bunch of pacifistic, postmaterialistic, high-trust societies, despite a long history of barbarism and bloodthirsty heathenism.

Compare Scandinavia with France, where Charlemagne brought civilization in the ninth century:

"A part of Charlemagne's success as warrior and administrator can be traced to his admiration for learning. His reign and the era it ushered in are often referred to as the Carolingian Renaissance because of the flowering of scholarship, literature, art, and architecture which characterize it. Charlemagne, brought into contact with the culture and learning of other countries... due to his vast conquests, greatly increased the provision of monastic schools and scriptoria (centres for book-copying) in Francia.

...The pan-European nature of Charlemagne's influence is indicated by the origins of many of the men who worked for him: Alcuin, an Anglo-Saxon from York; Theodulf, a Visigoth, probably from Septimania; Paul the Deacon, Lombard; Peter of Pisa and Paulinus of Aquileia, Italians; and Angilbert, Angilram, Einhard, and Waldo of Reichenau, Franks." --Wikipedia, Charlemagne

But no Scandinavians, there. And the fact that Scandinavia is presently one of the safest, wealthiest places to live on the planet, with extremely high literacy rates and low income equality, belies the claim that state or religious control of violence will gradually pacify a people.

The two elephants in the living room here, both jockeying in vain for attention, are IQ, and culture-as-culture. When we look at the many rapid revolutions and transformations which occur in societies in extremely short time spans, such as Japan's sudden transformation after the second world war, we see that many aspects of culture are not sorely the expression of individual personality at the large scale. And when the wild successes of IQ scores as predictors for societal functioning are added to the mix, there isn't necessarily any room for explanations involving impulse control or anger management.

I don't want to be pessimistic or discouraging, here; Peter has a great blog, and I very much enjoy reading it. But I have serious doubts as to whether his model will ever be able to work without modifications.

Anonymous I said...


peter said...

Still wonder if cause and effect go like described.
It could be that more pathogens goes with a more aggressive immune system. If the body is more in a defensive mode, it perceives enemies everywhere and violent retaliation is more likely.
So I would say it can still be that violence, religion, nationalism are a consequence of an active immune system, which in turn is a consequence of infections or vaccinations with adjuvants.