Saturday, October 25, 2014

The White Man's burden

From the Cape to Cairo, Puck, 1902. (Source: Library of Congress, public domain). The White Man's burden has been turned against itself. If the British adhere to a higher standard of civilization, their behavior must likewise be judged by a higher standard. They must play fair with former colonial peoples, but the latter are much less obliged to do the same.


Growing up in rural Ontario, I would talk with older folks about politics. A favorite topic was Quebec, and how those selfish French Canadians wouldn't fight in the Boer War, the First World War, and the Second World War. Later, as a student in Quebec City, I would hear the other side. French Canadians saw those wars as foreign entanglements of no concern to them. They were willing to fight and die, yes, but only for their own soil. That may seem selfish, but so were we with our slavish loyalty to the British Empire.

The folks back home would have disagreed. The Empire wasn't just for the British or even for Europeans in general. It was for people of all races and religions. It was an instrument for raising everyone up to British standards of fair play, morality, and civilization. In short, for making the world a better place. Take up the White Man's burden ...

Such talk puzzled me, even as a kid. The sun had long ago set on the British Empire. There was the Commonwealth, but why would its leaders defend our imperial heritage? Most of them had fought for independence from the Empire. They valued the British connection only to the extent that it was useful to themselves and their people.

Some Commonwealth leaders wouldn't even be that generous. When Robert Mugabe dispossessed the British farmers remaining in his country, we could only look on helplessly. A century ago, people called the Ottoman Empire the "sick man of Europe."  Today, that title surely applies to the remnants of the British Empire.

There is a difference, though. The Ottomans were militarily helpless. We are ideologically helpless. Our universal morality has been turned against us, and it is in the name of our notions of fair play that we're giving everything up, often to people, like Robert Mugabe, who make no pretence of believing in fair play. And we accept the logic of the situation. We think it normal to judge ourselves by a harsher standard and others by a more permissive one.

Double standards normally work the other way. Normally, one judges people of another kind by a harsher standard. They are less likely to share the same notions of right and wrong. They are also less likely to feel the sort of kinship affinity that makes people want to help each other and forgive minor wrongs, or even major ones. 

But we’re doing the reverse. That kind of situation is inherently unstable, even self-destructive. No other human society has ever attempted such a thing.


All of this seems obvious to me. Why is it less so to other people? The question crosses my mind when I see how thinking men and women respond—or rather fail to respond—to the Rotherham sex-abuse scandal. In an English town of some 250,000 people, at least 1,400 school-age girls were "groomed" for prostitution by gangs of Pakistani origin. Grooming begins with seduction and ends in abduction, trafficking, and confinement. This final stage apparently explains why some 500 girls were missing from the town's 15 to 19 age group at the last census.

This went on for years without anything being done and little being said. From time to time, the parents of the girls would complain, and the police would immediately investigate ... the parents. Finally, in August of this year, a long report broke the logjam of silence by officials and the media (Jay, 2014). There is still a pervasive bias against this news item, as seen in coverage by three online magazines. Slate ran one story about Rotherham and four about Jennifer Lawrence. Jezebel had one story about Rotherham and six about Jennifer Lawrence. Feministing made a passing reference to Rotherham and ran two stories about Jennifer Lawrence (Durant, 2014).

Who is Jennifer Lawrence? She's an American actress, and last August someone leaked nude photos of her online. That's why she matters so much more to thinking men and women.

It gets weirder. Social media have become overwhelmingly opposed to quarantining of the Ebola outbreak (Alexander, 2014). At one time, quarantines were considered a progressive measure, the sort of thing you would support as a thinking man or woman. If you didn't, people would assume you were a fool who knew nothing about modern science.

So what makes the Ebola outbreak different? The difference is simple. Quarantining means that light-skinned people will be detaining dark-skinned people. So we just can't do it. Because? Because.

The same applies to Rotherham, which was about dark-skinned men seducing, confining and, ultimately, enslaving light-skinned women. That, too, triggers the same mental lockdown—Don't go there! That's how thinking men and women unthinkingly respond—or almost anyone who has gone to college and watches TV. The response seems almost Cartesian: I try not to think, therefore I am a moral person.

Unfortunately, we cannot make unpleasant truths go away by ignoring them. Sooner or later, we will have to confront them. We will especially have to confront our universal morality, including the assumption that only light-skinned folks have moral agency and only they are to be held accountable for their actions.

Please don't get me wrong. I'm not arguing for a new improved universal morality. Morality can never be universal. It is a product of local conditions—to be specific, it arises from a co-evolving system of cultural, historical, and genetic factors. If forced to choose between saving one or the other, we should first save this foundational system. Anyhow, that's all we can really save. Morality has no existence above and beyond the humans who act it out in their daily lives.

That's a hard message to swallow, but we will have to. Eventually.


Alexander, S. (2014). Five case studies on politicization, Slate Star Codex, October 16  

Durant, J. (2014). John Durant compares coverage of Rotherham abuse vs. Jennifer Lawrence nudes, Twitchy Media, September 3

Jay, A. (2014). Independent Inquiry into Child Sexual Exploitation in Rotherham 1997-2013    

Saturday, October 18, 2014

Gender equality and gene-culture co-evolution

The ratio of index finger length to ring finger length provides an index of sexual differentiation (source: Wikicommons)


Are men and women more alike in some populations than in others? It's possible. First, boys and girls differentiate from each other to varying degrees during adolescence, and this process of sexual differentiation is genetically influenced. There are even conditions, like Swyer syndrome, where an individual is chromosomally male (46, XY) and yet develops externally into a woman.

Second, men and women don't have the same sex roles everywhere. According to a survey of 93 nonindustrial cultures, men were expected to dominate their wives in 67% of them, the sexes were expected to be about equal in 30%, and women were expected to dominate their husbands in 3% (Whyte, 1978). Sex roles differ to varying degrees even among hunter-gatherers, who correspond to the earliest stage of cultural evolution. In the tropics, women provide more food through gathering than men do through hunting. The reverse is true beyond the tropics, where women have few opportunities to gather food in winter (Kelly, 1995, pp. 128-132; Martin, 1974, pp. 16-18).

There has thus been a potential for gene-culture co-evolution. Wherever men and women behave more alike, natural selection will tend to level any innate behavioral differences between them. This can come about in several ways, but a particularly common one is to reduce the sex difference in prenatal hormonal exposure, i.e., the ratio of testosterone to estrogen in the uterine environment of the developing fetus.

We have a "handy" way to measure this prenatal influence. It's called the digit ratio: the length of your index finger divided by the length of your ring finger. The lower your 2nd digit to 4th digit ratio (2D:4D), the more you were exposed to testosterone in the womb and the less to estrogen.

English psychologist John T. Manning has pioneered the use of this digit ratio as a way to measure how prenatal male and female hormones influence various behavioral traits. In a recent study, he looked at how prenatal hormones might influence gender equality in different populations. After measuring the digit ratios of participants from 29 countries, his research team averaged the score for each country and compared it with indices of gender equality: women's share of parliamentary seats; women's participation in the labor force, women's education attainment level; maternal mortality rates; and juvenile pregnancy rates. To ensure comparability, all of the participants were of European descent.

The results?

In short, the more similar the two sexes were in 2D:4D, the more equal were the two sexes in parliamentary and labor force participation. The other variables were not as strongly correlated. (Manning et al., 2014)

In general, women from Northwest Europe have more masculine digit ratios, whereas women from farther east and south have more feminine digit ratios. This geographical trend is more pronounced for the right hand than for the left hand. Since the right-hand digit ratio is associated with social dominance, Northwest Europeans may be less sexually differentiated for that particular trait, as opposed to being less sexually differentiated in general.

Presumably, this isn't a new tendency. Women must have been more socially dominant among Northwest Europeans even before the late 19th century and the earliest movements for women's suffrage. So how far back does the tendency go? To medieval times? To pre-Christian times? It seems to go back at least to medieval times and, as such, forms part of the Western European Marriage Pattern:

The status of women differed immensely by region. In western Europe, later marriage and higher rates of definitive celibacy (the so-called "European marriage pattern") helped to constrain patriarchy at its most extreme level.

[...] In eastern Europe however, the tradition of early and universal marriage (usually of a bride aged 12-15 years, with menarche occurring on average at 14) as well as traditional Slavic patrilocal customs led to a greatly inferior status of women at all levels of society. (Women in the Middle Ages, 2014)

Does this geographic tendency go back to pre-Christian times? There is little consensus on this point, as noted in a study of women in Old Norse society:

The conversion of Iceland raises the problem of the impact of Christianity on the female half of the human race. This, in fact, is one of the most controversial issues in women's history. One point of view argues that Christianity was deeply imbued from the beginning with Jewish and Roman patriarchy, which became intensified by an all-male clergy and resulted in misogyny as the most lasting and profound legacy of Christianity for women. An opposite argument claims that the Christian message was fundamentally a liberating force that included women as well, and although the original radicalism of Jesus on this issue, as on so many others, became diluted with time, women were better off during the Christian period and in Christian countries than they had been before and elsewhere. (Jochen, 1995, p. 2)

Perhaps both arguments are true. As I have argued elsewhere, there may have been a "fruitful encounter" between Christianity and pre-existing behavioral tendencies in Northwest Europe, the result being a significantly different form of Christianity (Frost, 2014).


Frost, P. (2014). A fruitful encounter, Evo and Proud, September 26

Jochens, J. (1995). Women in Old Norse Society, Cornell University Press.

Kelly, R.L. (1995). The Foraging Spectrum. Diversity in Hunter-Gatherer Lifeways, Washington: Smithsonian Institution Press. 

Manning, J.T., B. Fink, and R. Trivers. (2014). Digit ratio (2D:4D) and gender inequalities across nations, Evolutionary Psychology, 12, 757-768.

Martin, M.K. (1974). The Foraging Adaptation - Uniformity or Diversity? Addison-Wesley Module in Anthropology 56. 

Women of the Middle Ages. (2014). Wikipedia 

Whyte, M. K. (1978). The status of women in preindustrial societies, Princeton, NJ: Princeton University Press.

Saturday, October 11, 2014

Yes, demons do exist

Chlamydia infection rate, by country (WHO 2004, Wikicommons). Sub-Saharan Africa has been a natural laboratory for the evolution of sexually transmitted pathogens, including strains that can manipulate their hosts.


Are we being manipulated by microbes? The idea is not so whacky. We know that a wide range of microscopic parasites have evolved the ability to manipulate their hosts, even to the point of making the host behave in strange ways. A well-known example is Toxoplasma gondii, a protozoan whose life cycle begins inside a cat. After being excreted in the cat's feces, it is picked up by a mouse and enters the new host's brain, where it neutralizes the fear response to the smell of cat urine. The mouse lets itself be eaten by a cat, and the protozoan returns to a cat's gut—the only place where it can reproduce (Flegr, 2013).

T. gondii can also infect us and alter our behavior. Infected individuals have longer reaction times, higher testosterone levels, and a greater risk of developing severe forms of schizophrenia (Flegr, 2013). But there is no reason to believe that T. gondii is the only such parasite we need to worry about. We study it in humans simply because we already know what it does in a non-human species.

Researchers are starting to look at manipulation by another human parasite, a sexually transmitted bacterium called Chlamydia trachomatis. Zhong et al. (2011) have found that it synthesizes proteins that manipulate the signalling pathways of its human host. These proteins seem to facilitate reinfection, although there may be other effects:

Despite the significant progresses made in the past decade, the precise mechanisms on what and how chlamydia-secreted proteins interact with host cells remain largely unknown, and will therefore still represent major research directions of the chlamydial field in the foreseeable future. (Zhong et al., 2011)

What else would a sexually transmitted pathogen do to its host? For one thing, it could cause infertility: 

While several nonsexually transmitted infections can also cause infertility (e.g., schistosomiasis, tuberculosis, leprosy), these infections are typically associated with high overall virulence. In contrast, STIs tend to cause little mortality and morbidity; thus, the effect on fertility seems to be more "targeted" and specific. In addition, several STI pathogens are also associated with an increased risk of miscarriage and infant mortality (Apari et al., 2014)

Chlamydia is a major cause of infertility, and this effect seems to be no accident. Its outer membrane contains a heat shock protein that induces cell death (apoptosis) in placenta cells that are vital for normal fetal development. The same protein exists in other bacteria but is located within the cytoplasm, where it can less easily affect the host's tissues. Furthermore, via this protein, Chlamydia triggers an autoimmune response that can damage the fallopian tubes and induce abortion. This response is not triggered by the common bacterium Escherichia coli. Finally, Chlamydia selectively up-regulates the expression of this protein while down-regulating the expression of most other proteins (Apari et al., 2014).

But how would infertility benefit Chlamydia and other sexually transmitted pathogens? Apari et al. (2011) argue that infertility causes the host and her partner to break up and seek new partners, thus multiplying the opportunities for the pathogen to spread to other hosts. A barren woman may pair up with a succession of partners in a desperate attempt to prove her fertility and, eventually, turn to prostitution as a means to support herself (Caldwell et al., 1989). This is not a minor phenomenon. STI-induced infertility has exceeded 40% in parts of sub-Saharan Africa (Apari et al., 2011).

It gets kinkier and kinkier

Does the manipulation stop there? We know, for instance, that sexual promiscuity correlates with the risk of contracting different STIs, but is this a simple relationship of cause and effect? Could an STI actually promote infidelity by stimulating sexual fantasizing about people other than one's current partner?

Let's look at another pathogen, Candida albicans, commonly known as vaginal yeast, which can cause an itchy rash called vulvovaginal candidiasis (VVC). Reed et al. (2003) found no significant association between VVC and the woman's frequency of vaginal sex, lifetime number of partners, or duration of current relationship. Nor was there any association with presence of C. albicans in her male partner. But there were significant associations with the woman masturbating or practicing cunnilingus in the past month.

VVC is thus more strongly associated with increased sexual fantasizing, as indicated by masturbation rate, than with a higher frequency of vaginal intercourse. This does look like host manipulation, although one might wonder why it doesn't translate into more sex with other men, this being presumably what the pathogen wants. Perhaps the development of masturbation as a lifestyle (through use of vibrators and pornography) is making this outcome harder to achieve.

A sexually transmitted pathogen can also increase its chances of transmission by disrupting mate guarding. This is the tendency of one mate, usually the male, to keep watch over the other mate. If mate guarding can be disabled or, better yet, reversed, the pathogen can spread more easily to other hosts. This kind of host manipulation has been shown in a non-human species (Mormann, 2010).

Do we see reversal of mate guarding in humans? Yes, it's called cuckold envy—the desire to see another man have sex with your wife—and it's become a common fetish. Yet it seems relatively recent. Greco-Roman texts don't mention it, despite abundant references to other forms of alternate sexual behavior, e.g., pedophilia, cunnilingus, fellatio, bestiality, etc. The earliest mentions appear in 17th century England (Kuchar, 2011, pp. 18-19). This was when England was opening up to world trade and, in particular, to the West African slave trade.

Sub-Saharan Africa has been especially conducive to sexually transmitted pathogens evolving a capacity for host manipulation. Polygyny rates are high, in the range of 20 to 40% of all adult males, and the polygynous male is typically an older man who cannot sexually satisfy all of his wives. There is thus an inevitable tendency toward multi-partner sex by both men and women, which sexually transmitted pathogens can exploit ... and manipulate.

What about sexual orientation?

A pathogen can also become more transmissible by giving its host a new sexual orientation. This strategy would disrupt the existing pair bond while opening up modes of transmission that may be more efficient than the penis/vagina one. Some vaginal strains of Candida albicans have adapted to oral sex by becoming better at adhering to saliva-coated surfaces (Schmid et al., 1995). Certain species that cause bacterial vaginosis, notably Gardnerella vaginalis and Prevotella, seem to specialize in female-female transmission (Muzny et al., 2013; Sobel, 2012).

Finally, there is the hypothesis that exclusive male homosexuality has a microbial origin (Cochran et al., 2000). Its main shortcomings are that (a) there is no candidate pathogen and that (b) exclusive male homosexuality has been observed in social environments with limited opportunities for pathogen transmission, such as small bands of hunter-gatherers across pre-Columbian North America (Callender & Kochems, 1983). On the other hand, there seems to have been a relatively recent shift in European societies from facultative to exclusive male homosexuality, so something may have happened in the environment, perhaps the introduction of a new pathogen (Frost, 2009).

Both male and female homosexuality seem to have multiple causes, but it’s likely that various pathogens have exploited this means of spreading to other hosts.


This is a fun subject when it concerns silly mice or zombie ants. But now it concerns us. And that's not so funny. Can microbes really develop such demonic abilities to change our private thoughts and feelings?

It does seem hard to believe. Perhaps this is an argument for intelligent design. After all, only an all-knowing designer could have made creatures that are so small and yet capable of so much ... things like inducing abortion, breaking up marriages, and altering normal sexual desires. Yes, such an argument could be made.

But I don't think anyone will bother.


Apari, P., J. Dinis de Sousa, and V. Muller. (2014). Why Sexually Transmitted Infections Tend to Cause Infertility: An Evolutionary Hypothesis. PLoS Pathog 10(8): e1004111.

Caldwell, J.C., P. Caldwell, and P. Quiggin. (1989). The social context of AIDS in sub-Saharan Africa, Population and Development Review, 15, 185-234.

Callender, C. and L.M. Kochems. (1983). The North American Berdache, Current Anthropology, 24, 443-470. 

Cochran, G.M., P.W. Ewald, and K.D. Cochran. (2000). Infection causation of disease: an evolutionary perspective, Perspectives in Biology and Medicine, 43, 406-448.

Flegr, J. (2013). Influence of latent Toxoplasma infection on human personality, physiology and morphology: pros and cons of the Toxoplasma-human model in studying the manipulation hypothesis, The Journal of Experimental Biology, 216, 127-133. 

Frost, P. (2009). Has male homosexuality changed over time, Evo and Proud, March 5

Kuchar, G. (2001). Rhetoric, Anxiety, and the Pleasures of Cuckoldry in the Drama of Ben Jonson and Thomas Middleton, Journal of Narrative Theory, 31 (1), Winter, pp. 1-30. 

Mormann, K. (2010). Factors influencing parasite-related suppression of mating behavior in the isopod Caecidotea intermedius, Theses and Disserations, paper 48 

Muzny, C.A., I.R. Sunesara, R. Kumar, L.A. Mena, M.E. Griswold, et al. (2013). Correction: Characterization of the vaginal microbiota among sexual risk behavior groups of women with bacterial vaginosis. PLoS ONE 8(12): 

Reed, B.D., P. Zazove, C.L. Pierson, D.W. Gorenflo, and J. Horrocks. (2003). Candida transmission and sexual behaviors as risks for a repeat episode of Candida vulvovaginitis, Journal of Women's Health, 12, 979-989. 

Schmid, J., P.R. Hunter, G.C. White, A.K. Nand, and R.D. Cannon. (1995). Physiological traits associated with success of Candida albicans strains as commensal colonizers and pathogens, Journal of Clinical Microbiology, 33, 2920-2926. 

Sobel, J.D. (2012). Bacterial vaginosis, Wolters Kluwer, UpToDate 

Zhong, G., L. Lei, S. Gong, C. Lu, M. Qi, and D. Chen. (2011). Chlamydia-Secreted Proteins in Chlamydial Interactions with Host Cells, Current Chemical Biology, 5, 29-37

Saturday, October 4, 2014

Making the big time ... elsewhere

Skull from Broken Hill (Kabwe), Zambia. This kind of human was still around when the Neanderthals were going extinct in Europe. (Wikicommons)


East Africa, 60,000 to 80,000 years ago. The relative stasis of early humans was being shaken by a series of population expansions. The last one went global, spreading out of Africa, into Eurasia and, eventually, throughout the whole world (Watson et al., 1997). Those humans became us.

This expansion took place at the expense of more archaic humans: Neanderthals in Europe, the Middle East, and Central Asia; Denisovans in East Asia; and mysterious hobbit-like creatures in parts of Southeast Asia.

And in Africa itself? We know less about those archaic humans, partly because the archeological record is so patchy and partly because ancient DNA does not survive as long in the tropics. Over time, the double helix breaks down, and this decomposition occurs faster at higher ambient temperatures. We'll probably never be able to reconstruct the genome of archaic Africans.

Yet they did exist. Surprisingly, they held out longer in parts of Africa than their counterparts did much farther away. A Nigerian site has yielded a skull that is only about 16,300 years old and yet looks intermediate in shape between modern humans on the one hand and Neanderthals and Homo erectus on the other. It resembles the skull of a very early modern human, like the ones who once lived at Skhul and Qafzeh in Israel some 80,000 to 100,000 years ago (Harvati et al., 2011; Stojanowski, 2014).

Archaic humans also held out in southern Africa. The Broken Hill or Kabwe skull, from Zambia has been dated to 110,000 years ago and looks very much like a Homo erectus (Bada et al., 1974; Stringer, 2011). This pre-sapiens human seems to have lasted into much later times. Hammer et al. (2011) found that about 2% of the current African gene pool comes from a population that split from ancestral modern humans some 700,000 years ago. They dated the absorption of this archaic DNA to about 35,000 years ago and placed it in Central Africa, since the level of intermixture is highest in pygmy groups from that region.

Cognitive modernity: less awesome on its home turf

Why did archaic humans survive longer in Africa than elsewhere? Some of them were more advanced than the Neanderthals or Denisovans, and perhaps better able to fend off invasive groups. This was the case with archaic West Africans, who seem to have been transitional between pre-sapiens and sapiens. They may have met modern humans on a more level playing field while enjoying the home team advantage.

On the other hand, archaic southern Africans look clearly pre-sapiens. What was levelling their playing field? Perhaps modern humans had advantages that were more useful outside Africa. Klein (1995) has argued that this advantage was cognitive, specifically a superior ability not only to create ideas but also to share them with other individuals via language—in a word, culture. This cognitive edge may have been more useful outside the tropics, where the yearly cycle forced humans to plan ahead collectively and keep warm collectively by building shelters and making garments. The result was a much wider range of human technology: deep storage pits for meat refrigeration; hand-powered rotary tools; kilns for ceramic manufacture; woven textiles; eyed sewing needles; traps and snares; and so on (Frost, 2014).

Modern humans were thus pre-adapted in Africa for later success elsewhere. We see this in their rapid penetration of cold environments unlike anything in their place of origin. By 43,500 years ago, they were already present in Central Europe at a time when it was barren steppe with some boreal forest in sheltered valleys (Nigst et al., 2014).

Pre-adaptation is a recurring oddity of evolution. A new ability may initially be a bit helpful and only later truly awesome. Does this mean that evolution anticipates future success? Well, no. It's just that the difference between failure and success—or between so-so success and the howling kind—often hinges on a few things that may or may not exist in your current environment. By moving to other environments, you increase your chances of finding one that will put your talents to better use. Success is fragile, but so is failure.


Bada, J.L., R.A. Schroeder, R. Protsch, & R. Berger. (1974). Concordance of Collagen-Based Radiocarbon and Aspartic-Acid Racemization Ages, Proceedings of the National Academy of Sciences (USA), 71, 914-917. 

Frost, P. (2014). The first industrial revolution, Evo and Proud, January 18

Hammer, M.F., A.E. Woerner, F.L. Mendez, J.C. Watkins, and J.D. Wall. (2011). Genetic evidence for archaic admixture in Africa, Proceedings of the National Academy of Sciences (USA), 108, 15123-15128.

Harvati, K., C. Stringer, R. Grün, M. Aubert, P. Allsworth-Jones, C.A. Folorunso. (2011). The Later Stone Age Calvaria from Iwo Eleru, Nigeria: Morphology and Chronology. PLoS ONE 6(9): e24024. doi:10.1371/journal.pone.0024024 

Klein, R.G. (1995). Anatomy, behavior, and modern human origins, Journal of World Prehistory, 9, 167-198. 

Nigst, P.R., P. Haesaerts, F. Damblon, C. Frank-Fellner, C. Mallol, B. Viola, M. Gotzinger, L. Niven, G. Trnka, and J-J. Hublin. (2014). Early modern human settlement of Europe north of the Alps occurred 43,500 years ago in a cold steppe-type environment, Proceedings of the National Academy of Sciences (USA), published online before print 

Stojanowski, C.M. (2014). Iwo Eleru's place among Late Pleistocene and Early Holocene populations of North and East Africa, Journal of Human Evolution, epub ahead of print 

Stringer, C. (2011). The chronological and evolutionary position of the Broken Hill cranium. American Journal of Physical Anthropology, 144(supp. 52), 287

Watson, E., P. Forster, M. Richards, and H-J. Bandelt. (1997). Mitochondrial footprints of human expansions in Africa, American Journal of Human Genetics, 61, 691-704. 0024024 

Friday, September 26, 2014

A fruitful encounter

Original Sin, by Michiel Coxie (1499-1592). Did the Christian doctrine of original sin create the guilt cultures of Northwest Europe? Or did the arrow of causality run the other way? (source: Wikicommons)


By definition, gene-culture co-evolution is reciprocal. Genes and culture are both in the driver's seat. This point is crucial because there is a tendency to overreact to cultural determinism and to forget that culture does matter, even to the point of influencing the makeup of our gene pool. Through culture, humans have directed their own evolution.

Take the ability to digest lactose, commonly called milk sugar. Among early humans, only babies could digest it because only they made the enzyme that breaks it down. This enzyme was lost as one grew up, with the result that milk consumption would cause indigestion, abdominal gas, and diarrhea. This is still the case in humans from much of Africa and Asia.

Then some cultures began to domesticate cattle, initially for meat. In times of famine, they turned to milk, and those who could better tolerate it had better chances of survival. So there was now natural selection for individuals who could produce the necessary enzyme not only in childhood but in adulthood as well.

The resulting evolutionary change was both genetic and cultural. With more and more adults being able to digest milk, it became possible to develop various dairy products, like cheese, and use milk as an ingredient in a wide range of foods. It also became possible to select for cattle that produce more and better milk (Beja-Pereira et al., 2003). A new way of life developed and thus brought about even more selection for this enzyme.

In sum, a genetic change can open up new paths for culture to follow and thereby create new paths for genes to follow. But that isn't all. The same situation can develop even when no genetic change has taken place, at least not initially. We see this, for instance, when a culture spreads out of one population and into another. The gene-culture interaction is new even though neither party to the interaction is new.

A fruitful encounter

One specific example is the encounter between Christianity and the guilt cultures of Northwest Europe, which differ from the shame cultures that prevail elsewhere. The difference is a major one. In a shame culture, your wrongdoings are punished only when witnessed by someone from your community. In a guilt culture, they are punished even when there is no witness, other than the one inside your head.

Guilt culture is commonly attributed to the Christian doctrine of original sin, and more specifically to the radicalization of this doctrine under Protestantism (see Note 1). Yet neither of these presumed causes really lines up with the presumed effect.

For one thing, it's doubtful whether this doctrine was even known to early Christians in the Middle East. True, Paul did write that humans had lost their immortality because of Adam's sin:

Therefore, just as through one man sin entered into the world, and death through sin, and so death spread to all men, because all sinned. Romans 5.12

This belief also appears in the Talmud, but it was never understood there as meaning that people are sinful because they inherit Adam's burden of sin. The Jewish view, like the later Muslim one, has been that people are sinful because they are imperfect beings. This was probably also the view of early Christians. Even today, Eastern Christians reject the doctrine of original sin, preferring the term "ancestral sin":

In the Orthodox Christian understanding, they explicitly deny that humanity inherited guilt from anyone. Rather, they maintain that we inherit our fallen nature. While humanity does bear the consequences of the original, or first, sin, humanity does not bear the personal guilt associated with this sin. (Original sin, 2014)

It was among Western Christians—Roman Catholics and, later, Protestants—that original sin developed into a doctrine. We see this in the writings of Irenaeus (2nd century) and Augustine (354-430), who identified the original sin as concupiscence, i.e., ardent, sensual longing. Protestantism is then said to have radicalized this doctrine, as seen in the Augsburg Confession of Lutheranism:

It is also taught among us that since the fall of Adam all men who are born according to the course of nature are conceived and born in sin. That is, all men are full of evil lust and inclinations from their mothers' wombs and are unable by nature to have true fear of God and true faith in God. Moreover, this inborn sickness and hereditary sin is truly sin and condemns to the eternal wrath of God all those who are not born again through Baptism and the Holy Spirit. 

But this radicalization was already under way before Protestantism. An English Catholic, Anselm of Canterbury (1033-1109), was the one who first separated original sin from concupiscence and defined it as "privation of the righteousness that every man ought to possess" (Original sin, 2014). Within Western Christendom, pre-Protestant England was likewise the epicenter of an intense penitential tradition that dated back at least to Anglo-Saxon times (Frantzen 1983). This tradition can be summed up as follows: "it is better to be shamed for one's sins before one man (the confessor) in this life than to be shamed before God and before all angels and before all men and before all devils at the Last Judgement" (Godden, 1973). The English abbot Aelfric of Eynsham (955-1010) described the need to do penance for all shameful acts, even those that are witnessed solely by spirits of the dead: 

He who cannot because of shame confess his faults to one man, then it must shame him before the heaven-dwellers and the earth-dwellers and the hell-dwellers, and the shame for him will be endless. (Bedingfield, 2002, p. 80)


As evidenced by the doctrine of original sin and the penitential tradition, Northwest European guilt culture was not a product of Christianity in general or of Protestantism in particular. It seems to have its origins in pre-existing tendencies that were absorbed into the new spiritual environment, much like the Christmas tree and other formerly pagan traditions. It thus grew steadily more important as the geocenter of Christianity moved steadily west and north.

This is not to belittle Christianity’s role. The new faith created ideological, social, and physical structures that were better at enforcing moral norms than anything beforehand. These norms may have had pagan antecedents, but they were now being enforced much more thoroughly.

We see this in the Medieval Synthesis that took hold from the 11th century onward, when Church and State joined forces to defend the Christian world: externally, through military campaigns against Muslims in the Iberian Peninsula, southern Italy, and the Middle East; and internally, through vigorous efforts to pacify social relations, either by increased use of capital punishment or by the Pax Dei—a Church-led movement to limit the scope of war in feudal society (Peace and Truce of God, 2014). Finally, guilt culture was strengthened through confession of one's sins, particularly after this practice became mandatory with the Fourth Lateran Council (1215). All wrongdoings had to be atoned at least once a year, however private or personal they might be (Sacrament of Penance, 2014).

Medieval Christian culture favored the survival and reproduction of people who previously would not have survived and reproduced. Conversely, by criminalizing personal violence, particularly in cases where the offender felt no guilt or remorse, this culture was now eliminating people for behavior that had once been admired.

It is often believed that Europe took off from the 15th century onward, when it expanded into Africa, the Americas, and Asia. Actually, the takeoff began earlier, particularly during this period when Church and State teamed up to lay a new basis for social relations. It was this new moral order that enabled Europe to get ahead (Frost, 2012). As Thomas Hobbes (1588-1679) wrote, no advanced society can develop where men have no "other security than what their own strength and their own invention shall furnish them withal." 

In such condition there is no place for industry, because the fruit thereof is uncertain: and consequently no culture of the earth; no navigation, nor use of the commodities that may be imported by sea; no commodious building; no instruments of moving and removing such things as require much force; no knowledge of the face of the earth; no account of time; no arts; no letters; no society; and which is worst of all, continual fear, and danger of violent death; and the life of man, solitary, poor, nasty, brutish, and short. [The Leviathan, 13]


Missionaries, for example, point to the relationship between Christianity and guilt culture:

There is a lack of a sense of sin in African thinking for many reasons: (1) there is a belief that God and the ancestors are unconcerned about private and public morality. People believe more in this life than the next life; (2) there is more of a shame-culture than a guilt-culture. People are more afraid of public opinion than of God; and (3) there is a focus on communal living where people look at who caused a problem. (Tittley, 2001)



Bedingfield, M.D. (2002). The Dramatic Liturgy of Anglo-Saxon England, The Boydell Press. 

Beja-Pereira A., G. Luikart, P.R. England, et al. (2003). Gene-culture coevolution between cattle milk protein genes and human lactase genes, Nature Genetics, 35, 311-313. 

Carroll, J. (1981). The role of guilt in the formation of modern society: England 1350-1800, The British Journal of Sociology, 32, 459-503. 

Frost, P. (2012). On global inequality, Evo and Proud, August 25

Frantzen, A.J. (1983). The literature of penance in Anglo-Saxon England, New Brunswick (N.J.): Rutgers University Press.

Godden, M.R. (1973). An Old English penitential motif, Anglo-Saxon England, 2, 221-239.

Hobbes, T. (2010). The Leviathan. Peterborough: Broadview Press. 

Lebra, T.S. (1971). The social mechanism of guilt and shame: the Japanese case, Anthropological Quarterly, 44, 241-255. 

Original Sin. (2014). Wikipedia 

Peace and Truce of God. (2014). Wikipedia 

Sacrament of Penance. (2014). Wikipedia  

Tittley, M. (2001). Book summary of The Primal Vision: Christian Presence amid African Religion, by John V. Taylor, SCM Press, 1963.

Saturday, September 20, 2014

Affective empathy, an evolutionary mistake?

The Classic of Filial Piety, Ma Hezhi, 12th century (Wikicommons). In China, empathy is experienced primarily as a moral duty, rather than as an involuntary emotional response.


In a previous post, I asked, "How universal is empathy?" The question is tricky because empathy has three components:

1. pro-social behavior - willingness to help people out, hospitality to strangers, acts of compassion.

2. cognitive empathy - capacity to see things from another person's perspective and to understand how he or she feels.

3. affective or emotional empathy - capacity not only to understand how another person feels but also to experience those feelings involuntarily and to respond appropriately. Failure to help a person in distress can trigger a self-destructive sequence: anguish, depression, suicidal ideation.

Pro-social behavior is very widespread among humans and may even be universal. It isn't unconditional, however. It can be used strategically and is often influenced by previous experiences with the person in question.

Cognitive empathy seems much less universal. In Oceanic cultures, for instance, there is both an unwillingness and an inability to know what other people feel. A person's inner feelings are said to be private and unknowable (Lepowski, 2011).

Affective empathy has an even more restricted range. If the range of empathic guilt is indicative, it may reach its highest incidences in the "guilt cultures" of northwestern Europe. In these cultures, guilt outweighs shame as a way to enforce social rules. What's the difference between the two? You feel shame when someone from your community sees you breaking a rule. With guilt, no witnesses are needed. You feel guilty when no else is watching or even when you merely think of breaking the rule.

Until recently, empathy has been studied only in Western populations, with the result that it is often assumed to have the same characteristics everywhere, at least potentially. This shortcoming was noted in a Hong Kong study: "A limitation of the existing literature on empathy in the social work context is that most of the existing studies on empathy are Western studies, and there are very few empirical studies of empathy in Chinese populations" (Siu and Shek, 2005)

When Siu and Shek (2005) studied empathy in a Chinese sample ranging from 18 to 29 years of age, they found that the participants made little distinction between cognitive empathy and affective (emotional) empathy. These two components seemed to be weakly differentiated from each other. The authors attributed this finding to "cultural differences" "Chinese people might not perceive the items from the two dimensions as too different in nature." The authors went on to note that "there are still debates concerning the boundaries of emotional and cognitive processes underlying empathy" and that "the causal relationships between cognitive and emotional processing underlying empathy are not simple or unidirectional."

In short, the Chinese participants could see things from another person's perspective and understand how that person felt. There is much less indication, however, that they involuntarily experienced the feelings of other people, especially feelings of distress. This is not to say they were incapable of such emotion transference, but rather that it seems limited in scope, perhaps being confined to family members and not extended to strangers.

In general, empathy is perceived in China as a moral duty and not as an involuntary emotional response. The authors underline this point when they discuss relevant beliefs in their culture:

These include the cultural beliefs of "qi suo bu yu, wu shi yu ren" (do not do unto others that you would not wish others to do on you), "jiang xin bi ji" (compare people's hearts with your own), "she shen chu di" (put yourself into other people's position), and "shen tong gan shou" (experiencing the experience of other people). With the emphases on collectivism and familism (Yang, 1981), taking the views of others is an essential duty, and the lack of consideration to others' perspectives is generally regarded as a lack of virtue in the Chinese culture (Wong, 1998). (Siu and Shek, 2005)

From cognitive empathy to affective empathy: the how and why

In humans, empathy seems to have differentiated progressively into its three components, with pro-social behavior being the oldest and most widespread one, followed by cognitive empathy and, finally, affective empathy.
This kind of mental evolution has been certainly possible in our species:

First, all three components display moderate to high heritability, especially the last one, i.e., 68% (Chakrabarti and Baron-Cohen, 2013). There has thus been a potential for gene-culture co-evolution.

Second, gene-culture co-evolution seems to have been widespread. About 10,000 years ago, human genetic evolution accelerated by over a hundred-fold, yet by that time our ancestors had colonized this planet from the tropics to the arctic (Hawks et al., 2007). They were evolving primarily in response to different cultural environments, and only secondarily to different physical environments.

Third, people have thus been selected for their ability to function in a certain cultural environment, just as they have been selected for their ability to function in heat or cold.

That answers the "how" question, but what about the "why"? Why was affective empathy more advantageous at the northwestern end of Eurasia? Together with empathic guilt, it may be part of a larger behavioral adaptation called the Western European Marriage Pattern, which seems to reflect a culture where kinship ties are relatively weak and thus insufficient to enforce rules of correct behavior.

The WEMP predominates north and west of an imaginary line running from Trieste to St. Petersburg and has the following general characteristics:

 - men and women tend to marry relatively late and many never marry

- children usually leave the family to form new households

- a high proportion of non-kin circulate among different households (Hajnal, 1965)

This zone of relatively weak kinship existed before the Black Death of the 14th century and is attested by fragmentary evidence going back to the 9th century and even earlier (Hallam, 1985; Seccombe, 1992, p. 94). I suspect its origins go back to a unique Mesolithic culture that once existed along the North Sea and the Baltic (Price, 1991). At that time, an abundance of marine resources drew people to the coast each year for fishing, sealing, and shellfish collecting, thus creating large but fluid settlements unlike anything seen in other hunter-gatherers. Social interactions would have largely involved non-kin, and there would have thus been strong selection for mechanisms that could enforce social rules in the absence of kin obligations.


Through their high capacity for affective empathy and empathic guilt, these Northwest Europeans had an edge in adapting to later cultural environments that would be structured not by kinship but by other ways of organizing social relations: the State, ideology, and the market economy.

This has been one path that leads to advanced societies, but it is not the only one. East Asian societies have pursued a similar path of cultural evolution while having relatively low levels of affective empathy and empathic guilt. They seem to have done so by relying more on external means of behavior control (shaming, family discipline, community surveillance) and by building on cognitive empathy through learned notions of moral duty.

Meanwhile, Northwest European societies have had their capacity for empathy pushed to the limit, as seen in the commonly heard term "aid fatigue." And there is no easy way to turn it off. The only real way is to convince oneself that the object of empathy is morally worthless.

Was it all an evolutionary mistake? Time will tell.


Chakrabarti, B. and S. Baron-Cohen. (2013). Understanding the genetics of empathy and the autistic spectrum, in S. Baron-Cohen, H. Tager-Flusberg, M. Lombardo. (eds). Understanding Other Minds: Perspectives from Developmental Social Neuroscience, Oxford: Oxford University Press.  

Hajnal, J. (1965). European marriage pattern in historical perspective. In D.V. Glass and D.E.C. Eversley (eds). Population in History, Arnold, London.

Hallam, H.E. (1985). Age at first marriage and age at death in the Lincolnshire Fenland, 1252-1478, Population Studies, 39, 55-69.

Hawks, J., E.T. Wang, G.M. Cochran, H.C. Harpending,& R.K. Moyzis. (2007). Recent acceleration of human adaptive evolution. Proceedings of the National Academy of Sciences (USA), 104, 20753-20758.

Lepowsky, M. (2011). The boundaries of personhood, the problem of empathy, and "the native's point of view" in the outer islands, in D.W. Hollan, C. J. Throop (eds).The Anthropology of Empathy: Experiencing the Lives of Others in Pacific Societies, (pp. 43-68), New York: Berghahn.

Price, T.D. (1991). The Mesolithic of Northern Europe, Annual Review of Anthropology, 20, 211-233.  
Seccombe, W. (1992). A Millennium of Family Change. Feudalism to Capitalism in Northwestern Europe, London: Verso.

Siu, A.M.H. and D.T. L. Shek. (2005). Validation of the Interpersonal Reactivity Index in a Chinese Context, Research on Social Work Practice, 15, 118-126.