South Korea's experiment

Mid-term exams at a South Korean middle school (Wikicommons - Samuel Orchard)



South Korea opened up to mail-order brides a quarter of a century ago. Most are from Southeast Asia (Philippines, Vietnam, Cambodia, and Indonesia), although some are ethnic Koreans from northeast China. Men outnumber women in South Korea, as they do elsewhere in East Asia, and the male surplus is even larger in rural areas because of the many women who move to cities for employment (Park 2011). 

As a result, 472,390 "multicultural marriages" were performed between 2000 and 2016 (Lim 2017). In 2005, the peak year, 13% of all marriages involved a foreign-born bride. This way of finding a bride has been especially popular in rural areas, where 40% of all couples are mixed (Park 2011). The offspring of these marriages "are expected to number over 1.6 million by 2020, with a third of all children born that year the offspring of international unions" (Lim 2011). In rural areas, this proportion is expected to be half of all children by 2020 (Park 2011).

Such children will increase both in absolute numbers and proportionately for three reasons. First, they are born mostly in rural areas, where incentives for childbearing are relatively high. Second, their mothers come from cultures where fertility is likewise relatively high. Third, Korean women have a very low fertility rate: only 0.98 children per woman in 2018.

South Korea is thus on track for rapid demographic replacement. This change is interesting not only because of its rapidity but also because it is happening in a country that differs considerably from Western Europe and North America in history and culture. Negative effects cannot be blamed on slavery, colonialism, or other chickens coming home to roost. Until the twentieth century the country kept to itself, to such a point that it was called "The Hermit Kingdom." There then followed Japanese rule, American occupation, and devastating war. Not until the 1980s did South Korea become truly advanced, and affluent.

So can South Korea change its population and remain advanced and affluent? This question is all the more relevant because the country has only one natural advantage in the global marketplace: its human capital.


Academic failure

In general, children of mixed parentage do badly at school: "The drop-out rate among mixed-blood youths is estimated at 9.4% in elementary schools and 17.5% at the secondary level, compared with less than 3% among ordinary Korean youths" (Kang 2010).

This poor performance is usually put down to the mother's poor language skills. "Because their mothers have difficulty in speaking and writing Korean, these children may be making slow progress in language development in comparison to the Korean children" (Kang 2010). If this explanation is correct, such children should do worse in subjects that demand much social interaction and language use. Conversely, they should do better in subjects that require abstract skills, like mathematics, or memorization of names and dates, like social studies. This is, in fact, the pattern we see in children of East Asian immigrants in North America.

But this is not the pattern we see in children born in South Korea to non-Korean mothers: "Their favourite subjects are music/painting/physical education (42.6%), while they dislike math (38.1%), social studies (19.2%) and Korean (12.7%)" (Kang 2010). The learning deficit seems to be strongest in those subjects that require the most abstraction and memorization.

Moreover, a study conducted over several months found that these children do not have language problems that can be traced to deficient learning at home from their mothers: "This study revealed that multicultural children did not exhibit any difficulty in communicating with others in everyday Korean but that they had varying degrees of academic vocabulary mastery" (Shin 2018). So the problem is not with learning of normal spoken language at home but with learning of specialized terminology at school. The study's author concluded: “This finding then raises the questions of why the simplified discourse about multicultural children's deficiency in Korean has been easily accepted as true in society and who benefits from the (re)production of the idea that they need special care, particularly regarding Korean language instruction” (Shin 2018).


Non-compliance with social rules

Koreans are expected to show a high level of compliance with social rules. These rules may apply to everyone (e.g., wearing seatbelts) or only to students (e.g., no smoking, mandatory hand washing). Compliance seems to be weaker in children of foreign-born mothers, as suggested by lower rates of hand washing and wearing of seatbelts and higher rates of smoking (Yi and Kim 2017).


Suicidal ideation and suicidal attempts

Children of mixed parentage are more likely to contemplate and attempt suicide, but this seems to be related more to decreased self-control than to increased depression or stress. Kim et al. (2015) concluded: "There was no significant difference in the levels of depression, self-reported happiness, and self-reported stress between adolescents from multicultural and monocultural families. However, suicidal ideation and suicidal attempt were significantly higher in adolescents from multicultural families."


Violence and hyperactivity

Children of mixed parentage also show higher levels of hostility, fear, anxiety, and anger (Moon and An 2011). Between the ages of 5 and 12 years they are more likely to engage in hyperactive behaviors, as rated by their teachers (Park and Nam 2010). Finally, between the ages of 11 and 13 years they are more prone to delinquency and aggression (Lee et al. 2018).

On the other hand, Yu and Kim (2015) found higher incidences of violence at school and non-compliance with rules (smoking, drug use, alcohol use, sexual activity) only in children of foreign-born fathers and native-born mothers. Children of foreign-born mothers and native-born fathers were behaviorally similar to children of native-born mothers and native-born fathers. It is true that the other studies lump all “multicultural” children together, making no distinction between those with foreign-born mothers and those with foreign-born fathers. However, the second group is much smaller than the first—too small to explain the differing results. This may be seen in the study by Yu and Kim (2015), which had 88 binational children of foreign-born fathers versus 622 of foreign-born mothers.

The findings of Yu and Kim (2015) also run counter to the standard acculturation model. A child normally has a stronger bond with its mother than with its father, so a child should better assimilate Korean behavioral norms if its mother is Korean than if its mother is non-Korean. But here we see the reverse.


Conclusion

The most robust finding is that children of mixed parentage do poorly at school. The reason is commonly said to be poor language skills, yet the pattern of academic failure is actually the opposite of what that explanation would predict. Moreover, these children seem to have no trouble with everyday spoken Korean. Their problem is with specialized vocabulary that is normally learned at school and not at home.

Children of mixed parentage also seem to be less compliant with rules and more prone to violence and hyperactivity. This was the finding of three out of four studies. The underlying cause may be weaker mechanisms for self-control, self-discipline, and internalization of social rules. This factor may also play a role in the higher incidences of suicidal ideation and suicidal attempts.

In the academic literature, these findings are explained in terms of normal versus abnormal development. Children of mixed parentage are said to develop abnormally because they are more interested in music and physical education than in math. Their higher levels of violence and hyperactivity are explained the same way.  But what if they had been assessed in their mothers' home countries? Would they still seem so abnormal? On a global level, few societies expect the degree of academic nerdiness that Koreans expect of themselves. 

Better research is needed. My first suggestion: provide data on ethnicity. It’s not enough to distinguish between "native-born" and "foreign-born." A foreign-born mother could be an ethnic Korean from China who has more in common with a native-born mother. There may also be significant behavioral differences among binational children depending on which Southeast Asian country the mother comes from. The relevant factor is really ethnicity and not place of birth.

This factor may explain why children are less violent when they have foreign mothers and Korean fathers than when they have Korean mothers and foreign fathers. The foreigners are ethnically different in the two cases. In the first case, they are Southeast Asians. In the second case, they are either U.S. servicemen or migrant laborers who come not only from Southeast Asia but also from South Asia, Southwest Asia, and Africa.

My second suggestion: do not frame the issue solely in terms of "acculturation." i.e., insufficient learning by children of Korean culture, particularly the Korean language. This is not to say that acculturation is never a causal factor, but rather that it is assumed to be the only one, even to the point of misrepresenting reality.

Yes, culture does matter, but it interacts with other factors, including genetic ones. Humans everywhere have had to adapt to their cultural environment—more so, in fact, than to their natural environment—and this has been no less true for the Korean people. To survive in a highly complex and demanding culture, they have had to acquire certain mental capabilities:

- high cognitive ability (mean IQ of 106)

- high self-control

- high degree of compliance with social rules

- low time preference and, correspondingly, strong future-oriented thinking

- strong inhibition of violence, which can be released only if permitted by social rules

All of these mental capabilities have moderate to high heritability and are no less real than the more visible aspects of the human body, like gender, skin color, and body height. They exist because they have enabled Koreans to survive and flourish in a specific cultural environment

The Korean people have achieved a high standard of living through their knowledge, foresight, and self-discipline—qualities that are the outcome of a long process of gene-culture coevolution. Generation after generation of their ancestors have had to adapt to the demands of a harsh cultural environment, this adaptation being bought at a high price: the success of some individuals and the failure of many more. This is why Koreans traditionally revere their ancestors.

All of this has been gained through much effort over many generations, but it can all be lost in one or two. To do or to undo—which do you think is easier?   


References

Kang, S.W. (2010). Multicultural education and the rights to education of migrant children in South Korea. Educational Review 62(3): 287-300.
https://books.google.ca/books?hl=fr&lr=&id=sgnKAwAAQBAJ&oi=fnd&pg=PA37&ots=IcekxniSRj&sig=vQ-YWHSlouQuzFor5zP9OOkucsg#v=onepage&q&f=false 

Kim, J-M., B-G. Kong, J-W. Kang, J.-J. Moon, D.-W. Jeon, E.-C. Kang, H.-B. Ju, Y.-H. Lee, and D.-U. Jung. (2015). Comparative Study of Adolescents' Mental Health between Multicultural Family and Monocultural Family in Korea. Journal of the Korean Academy of Child and Adolescent Psychiatry 26(4): 279-287.
https://www.e-sciencecentral.org/articles/SC000022127

Lee, J.S., J.M. Kim, and A.R. Ju. (2018). A structural analysis on the effects of children's parentification in multicultural families on their psychological maladjustment - comparison with children in monocultural families. Journal of the Korea Institute of Youth Facility and Environment 16:117-130.
https://www.earticle.net/Article/A329970 

Lim, T. (2011). Korea's multicultural future? The Diplomat, July 20
https://thediplomat.com/2011/07/south-koreas-multiethnic-future/

Lim, T. (2017). The road to multiculturalism in South Korea. Georgetown Journal of International Affairs, October 10
https://www.georgetownjournalofinternationalaffairs.org/online-edition/2017/10/10/the-road-to-multiculturalism-in-south-korea 

Moon SH, and H.J. An (2011). Anger, anger expression, mental health and psychosomatic symptoms of children in multi-cultural families. Journal of Korean Academy of Psychiatric and Mental Health Nursing 20(4): 325-333.
https://synapse.koreamed.org/DOIx.php?id=10.12934/jkpmhn.2011.20.4.325

Park, S. (2011). Korean Multiculturalism and the Marriage Squeeze. Contexts 10: 64-65.
https://journals.sagepub.com/doi/full/10.1177/1536504211418459 

Park, J.H., and J.S. Nam (2010). The language development and psychosocial adjustment of multicultural children. Studies on Korean Youth. 21:129-152.

Yi, Y., and J-S. Kim. (2017). Korean Adolescents' Health Behavior and Psychological Status according to Their Mother's Nationality. Osong Public Health and Research Perspectives 8(6): 377-383.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5749486/ 

Shin, J. (2018). Minority youth's mastery of academic vocabulary and its implications for their educational achievements: the case of 'multicultural adolescents' in South Korea. Multicultural Education Review 10(1): 35-51,
https://www.tandfonline.com/doi/abs/10.1080/2005615X.2018.1423539 

Yu, J-O, and M. Sung Kim. (2015). A Study on the Health Risk Behaviors of Adolescents from Multicultural Families according to the Parents' Migration Background. Journal of Korean Academy of Community Health Nursing 26(3):190-198
https://synapse.koreamed.org/DOIx.php?id=10.12799/jkachn.2015.26.3.190

Our brideprice culture

Dr. Griskevicius speaking on the mating game. The economic consequences are big. (source)

The mate market isn’t what it used to be. As late as the mid-1970s, single women outnumbered single men at all reproductive ages. A reversal then took place throughout the Western world. The “operational sex ratio” slipped from male scarcity to parity and then to a male surplus by the late 1980s. Why? The immediate reason was the large number of divorced male baby-boomers reentering the mate market … and competing for a smaller number of female baby-busters (Ni Bhrolchain & Sigle-Rushton, 2005; Pedersen, 1991).

Yet behind this immediate reason stood two longer-term causes. First, divorce had become much easier. Men were now freer to act on an unconscious command that all men are born with: Look for a younger wife if your current one no longer looks fertile … assuming of course you’ve managed to survive into your fifth decade of life.

This leads us to the second cause. By the late 20th century, male mortality had greatly declined. More men were now living throughout the entire reproductive age bracket. Keep in mind that around 105 boys are born for every 100 girls. In the past, this sex ratio balanced out within the first few years of life because of higher mortality among male infants. By the 1980s, it wasn’t balancing out until the mid-40s or even later.

Will the operational sex ratio return to normal in the future? No, but it may stop getting worse. The trend toward male longevity seems to have almost maxed out for all reproductive ages. And fewer older men will be reentering the mate market—the baby boomers are getting a bit old for that sort of thing. But then we’ll probably also see more polygyny of the non-serial kind. Simultaneous polygyny is hard to measure, since it’s illegal, but it seems to be a growing phenomenon. The incidence of gonorrhea and chlamydial infection is now higher in women than in men, an indication that the population of promiscuous individuals is disproportionately female (Miller et al., 2004).

Even if we ignore unofficial polygyny, the “official” ratio of single men to single women shows no signs of declining, even at older ages (Soma, 2008). In Germany, single men now outnumber single women up to the age of 60 (Glowsky, 2007). To make a long story short, young nubile women are a limited resource. The more you deregulate the marriage market and the more you reduce male mortality, the fewer of them there’ll be to go around.

And the consequences?

As men become increasingly outnumbered on the mate market, what will be the consequences? Until recently, research has focused on the social effects. Permanently single men have less of a stake in maintaining the status quo and tend to be drawn to revolutionary movements of one sort or another (Hudson & Den Boer, 2002).

Now it appears that there are also economic consequences:

Findings show that male-biased sex ratios (an abundance of men) lead men to discount the future and desire immediate rewards. Male-biased sex ratios decreased men’s desire to save for the future and increased their willingness to incur debt for immediate expenditures. Sex ratio appears to influence behavior by increasing the intensity of same-sex competition for mates. Accordingly, a scarcity of women led people to expect men to spend more money during courtship, such as by paying more for engagement rings. (Griskevicius et al, 2012)

In the above study, the operational sex ratio (ratio of adult unmarried men to adult unmarried women) was compared to the number of credit cards owned and the amount of consumer debt for 134 American cities. Both indices significantly correlated with the operational sex ratio. By way of example, the authors point to two cities in Georgia:

Macon, Georgia, and Columbus, Georgia, are two cities in the southeastern United States that are less than a hundred miles apart. Both cities share a similar historical heritage and economic climate. Despite these similarities, the residents of each city have drastically different spending habits: The average consumer debt of people living in Columbus is an astounding 2.7 standard deviations higher than that of people living in Macon—a difference of $3,479 per consumer […]

 

We suggest that this difference in debt might be linked to an often overlooked difference between the two cities: the ratio of single adult men to women in each area. Whereas in Macon there are only 0.78 single men for every woman, in Columbus there are 1.18 single men for every woman. (Griskevicius et al, 2012)

The United States, like most of the Western world, is moving from a dowry culture to a brideprice culture (Sailer, 2008). Single men now have to pay to get a wife, and the price is getting steeper.

But this change isn’t just a matter of “Who pays the money?” It’s also “How is it spent?” A dowry is an investment in the future. It often takes the form of a down-payment by the bride’s family on the newlyweds’ home. In contrast, a bride price usually goes toward immediate consumption. A single man has to spend more on dating, which itself is becoming a longer, multiyear process. He’ll be expected to pay off his bride’s credit card debt. And he’ll have to spend more on the wedding.

The difference between dowry and bride price reflects a difference in mate-choice criteria. Whereas men judge women on the basis of youth and perceived fertility, women judge men on the basis of perceived social and economic status. A shift towards bride price thus compels men to boost their image by spending more now and leaving less for the future.

There is a widespread belief that consumers will save and pay off their debts if offered the right economic incentives, i.e., higher interest rates, tax deductions, etc. This belief ignores the changes that have occurred to the dynamics of mating over the last few decades. Men will keep on going heavily into debt because that’s the price of getting a mate. Women will continue to borrow beyond their means, knowing that they can convert their debt burden into bride price. 

References

Glowsky, D. (2007). Why do German men marry women from less developed countries? SOEP papers on Multidisciplinary Panel Data Research #61
http://www.dix.de/soeppapers

Griskevicius, V., J.M. Tybur, J.M. Ackerman, A.W. Delton, T.E. Robertson, & A.E. White. (2012). The financial consequences of too many men: Sex ratio effects on saving, borrowing, and spending, Journal of Personality and Social Psychology, 102(1), 69-80.

Griskevicius, V. (2012). Youtube video http://www.youtube.com/watch?v=PY706EGtUnY

Hudson, V.M., & A. Den Boer. (2002). A surplus of men, a deficit of peace. Security and sex ratios in Asia’s largest states, International Security, 26, 5-38.

Miller, W.C., C.A. Ford, M. Morris, M.S. Handcock, J.L. Schmitz, M.M. Hobbs, M.S. Cohen, K.M. Harris, & J.R. Udry. (2009). Prevalence of chlamydial and gonococcal infections among young adults in the United States, Journal of the American Medical Association, 291, 2229-2236.

Ni Bhrolchain, M. & W. Sigle-Rushton. (2005). Partner supply in Britain and the U.S. Estimates and gender contrasts, Population, 60, 37-64.

Pedersen, F.A. (1991). Secular trends in human sex ratios: Their influence on individual and family behavior, Human Nature, 2, 271-291.

Sailer, S. (2008). Bachelorettes in debt – the new reverse dowry system, Steve Sailer’s iSteve blog, November 7  http://isteve.blogspot.ca/2008/11/bachelorettes-in-debt-new-reverse-dowry.html

Soma. (2008). The new interactive singles map http://www.xoxosoma.com/singles/

Is eye color sex-linked?

Averaged face of blue-eyed male subjects (left). Averaged face of brown-eyed male subjects (right). Czech population. (Kleisner et al., 2010)

If sexual selection of women diversified the eye color of early Europeans, the new colors should tend to be sex-linked, since the selection targeted women more than men. There is now evidence that blue eyes are linked to feminization of face shape.

Throughout most of the world, humans have brown eyes, black hair, and varying shades of dark skin. An exception is Europe, especially its northern and eastern portions. Here, eyes are not only brown but also blue, gray, hazel, or green. Hair is not only black but also brown, flaxen, golden, or red. Finally, skin has been whitened to the end point of depigmentation.

How can we explain this unusual color pattern? Is it simply due to lightening of skin color? In other words, did reduction of skin pigmentation incidentally reduce eye and hair pigmentation? The diverse palette of eye and hair colors would thus be a side effect of selection for lighter skin.

This explanation is dubious. For one thing, the gene loci are not the same. European skin has whitened mainly through allelic change at SLC45A2 (AIM1) and SLC24A5 (Soejima et al., 2005; Voight et al., 2006). European hair has diversified in color through a proliferation of new alleles at MC1R (Makova & Norton, 2005; Rana et al., 1999). European eyes have diversified in color mainly through a proliferation of new alleles at the OCA2-HERC2 gene complex (Duffy et al., 2007; Kayser et al., 2008; Sturm & Frudakis, 2004; Sturm et al., 2008).

Some of these novel hair and eye colors are also associated with lighter skin, notably the red hair and blue eye phenotypes. But why would selection for lighter skin lead to a proliferation of new alleles for hair and eye color—most of which have little or no influence on skin color? Why is it that red hair and blue eyes have not reached fixation in any human population, even those with milk-white skin?

Sexual selection?

I have argued that the cause was an intensification of sexual selection among early Europeans, specifically sexual selection of women (Frost, 2006; Frost, 2008). When too many women have to compete for too few men, there is selection for visible female traits that hyperstimulate certain algorithms in the male brain, particularly those for gender recognition or fertility assessment.

Among hunter-gatherers—and all humans were hunter-gatherers until 10,000 years ago, sexual selection of women tends to intensify farther away from the equator. On the one hand, hunting distances lengthen, thus increasing male mortality. On the other, polygyny becomes less common because women are less able to provide for themselves and their children in winter, thus making it costlier for a man to provide for a second wife. Result: a growing imbalance between the numbers of women and men on the mate market.

Among early modern humans, these two equator-to-arctic trends reached a common end-point in the steppe-tundra of northern Eurasia, such as existed during the last ice age (25,000 – 10,000 years ago). Hunting distances were very long because almost all food came from highly mobile herds of mammals, notably reindeer. Male provisioning was similarly at a maximum, women having little or no food autonomy.

The Eurasian steppe-tundra was continuously inhabited only in portions of its European end, where it ran farther south because of the large icecap over Scandinavia and where the moderating influence of the Atlantic Ocean and the Gulf Stream made the climate moister and milder. Here, the effects of intense sexual selection could accumulate and be passed on from generation to generation. Conversely, northern Asia appears to have suffered episodes of complete depopulation, particularly at the height of the last ice age.

Sexual selection: color novelty and color diversification

When sexual selection is weak, the adaptive equilibrium is dominated by selection for a dull, cryptic appearance that reduces detection by predators (Kirkpatrick, 1987). As sexual selection grows stronger, the equilibrium shifts toward a more noticeable appearance that retains the attention of potential mates, typically by means of vivid and/or novel colors.

One outcome may be a polymorphism of brightly colored phenotypes, due to selection shifting to scarcer and more novel hues whenever a color variant becomes too common (Endler, 1980; Frost, 2006; Hughes et al., 1999; Hughes et al., 2005; Olendorf et al., 2006). This frequency dependence has been shown in humans. Thelen (1983) presented male participants with slides showing attractive brunettes and blondes and asked them to choose, for each series, the woman they would most like to marry. One series had equal numbers of brunettes and blondes, a second 1 brunette for every 5 blondes, and a third 1 brunette for every 11 blondes. Result: the rarer the brunettes were in a series, the likelier any one of them would be chosen.

But why would this stronger selection diversify hair and eye color while simply whitening skin color? The answer seems to be that sexual selection acts on skin color not only through rare-color preference but also by hyperstimulating a gender-recognition algorithm, i.e., by accentuating a visible female-specific trait. In our species, female skin has less melanin and hemoglobin than does male skin, i.e., women look paler, men browner and ruddier (Edwards & Duntley, 1939; Hulse, 1967; Jablonski & Chaplin, 2000).

Sex linkage?

If European skin had whitened through selection for lighter-skinned women, it should have whitened more in women than in men, thus becoming more sexually dimorphic. Yet skin color actually seems to be less dimorphic in Europeans than in other humans (Madrigal & Kelly, 2006). This finding does not necessarily invalidate the sexual selection hypothesis. It may be that the pigmentary sex difference cannot fully express itself in light-skinned populations. Skin color is dimorphic because girls progressively lighten in color during adolescence, and such lightening may be less easily expressed if melanin production is already low. Indeed, this dimorphism seems to be almost absent in people whose skin starts off with very little pigment, such as Dutch and Belgian subjects (Frost, 2007).

And hair and eye color? Sexual selection of women should favor novel hair and eye colors more so in women than in men. Granted, both polymorphisms arose over a short and relatively recent span of time, so sexual selection would have worked with those alleles that were initially available and, for the most part, not sex-linked. But surely a few of these mutant alleles would have been sex-linked and, as such, favored over non-sex-linked ones.

This does seem to be the case with hair color. Blond hair darkens with age more slowly in women than in men (Olivier, 1960, p. 74). A ‘digit ratio’ study indicates that prenatal exposure to estrogen is higher in individuals with blond hair or non-brown eyes (Mather et al., unpublished). The same study, however, found no evidence of sexual dimorphism. Women and men had roughly the same proportions of hair and eye colors among the 18-to-38 year olds under study. Such a dimorphism, if it does exist, may be a transient one limited to younger age groups.

Moreover, Kleisner et al. (2010) have found an apparent sex linkage between blue eyes and feminization of face shape. They initially wished to determine whether eye color influences perception of male dominance, using facial pictures of Czech men. The results showed that brown-eyed men were rated as more dominant than blue-eyed men. As a control, the authors repeated the experiment after altering the facial photos of the brown-eyed men to make them blue-eyed. These altered photos were still rated as more dominant.

Careful study of the photos revealed that the brown-eyed men had more masculine facial features:

In contrast with blue-eyed males, brown-eyed males have statistically broader and rather massive chins, broader (laterally prolonged) mouths, larger noses, and eyes that are closer together with larger eyebrows. In contrast, blue-eyed males show smaller and sharper chins, mouths that are laterally narrower, noses smaller, and a greater span between the eyes.

The perception of brown-eyed men as more dominant is thus due to their more masculine facial appearance—and not to their brown eyes. The authors suggest that some kind of sex linkage may be responsible, while adding: “Repeating this study in other populations with polymorphism in eye color can test this hypothesis.”

If true, this finding would be consistent with Liberton et al. (2009) who found that European face shape has differentiated from West African face shape through a selective force that has acted primarily on women. Both findings, in turn, would support my argument that many of the differences we see among human populations are not due to differences in natural selection, and hence differing natural environments. Instead, the cause lies in differing intensities of sexual selection, and whether this selection has primarily targeted men or women (Frost, 2008).

When men are the prime targets of sexual selection, as in tropical ‘female farming’ societies, the result is accentuation of certain male features. Meanwhile, there is a slackening of female-targeted sexual selection, which leads to women having a more functional and less ornamental appearance. This pattern is reversed when women are the prime targets of sexual selection (Frost, 2008).

Ethnic substructure?

There is admittedly an alternate explanation for the above finding: ethnic substructure among the Czech subjects. The Czech Republic has historically been home to ethnic minorities who statistically differ from ethnic Czechs in facial appearance, i.e., Jews, Germans, and Roma. Jews and Roma, like other populations of Mediterranean or southwest Asian origin, tend to have brown eyes and a more robust face shape. Conversely, Germans are likelier to have blue eyes and more gracile faces. Although the Jewish and German communities were severely decimated during World War II and its aftermath, with many survivors later emigrating, there still remain significant numbers of Czech citizens who are wholly or partly of Jewish or German origin. Since WWII, there has also been an influx of Roma into the Czech Republic.

It would be difficult to rule out this kind of explanation, even if one questioned the subjects of the study. After the last war, many Czech citizens of Jewish or German origin felt it best to conceal their ancestry, for fear of discrimination or even expulsion from the country. Today, their grandchildren may be completely unaware of their origins.

This is all the more reason to replicate the results with subjects from another population, preferably one with as little ethnic substructure as possible.

References

Duffy, D.L., G.W. Montgomery, W. Chen, Z.Z. Zhao, L. Le, M.R. James, N.K. Hayward, N.G. Martin, & R.A. Sturm. (2007). A three-single-nucleotide polymorphism haplotype in intron 1 of OCA2 explains most human eye-color variation. American Journal of Human Genetics, 80, 241-52.

Edwards, E.A., & S.Q. Duntley. (1939). The pigments and color of living human skin. American Journal of Anatomy, 65, 1-33.

Endler, J.A. (1980). Natural selection on color patterns in Poecilia reticulata. Evolution, 34, 76‑91.

Frost, P. (2008). Sexual selection and human geographic variation, Special Issue: Proceedings of the 2nd Annual Meeting of the NorthEastern Evolutionary Psychology Society. Journal of Social, Evolutionary, and Cultural Psychology, 2(4),169-191.

http://www.jsecjournal.com/articles/volume2/issue4/NEEPSfrost.pdf

Frost, P. (2007). Comment on Human skin-color sexual dimorphism: A test of the sexual selection hypothesis, American Journal of Physical Anthropology, 133, 779-781.

Frost, P. (2006). European hair and eye color - A case of frequency-dependent sexual selection? Evolution and Human Behavior, 27, 85-103.

Hughes, K.A., L. Du, F.H. Rodd, & D.N. Reznick. (1999). Familiarity leads to female mate preference for novel males in the guppy, Poecilia reticulata. Animal Behaviour, 58, 907-916.

Hughes, K.A., F.H. Rodd, & D.N. Reznick. (2005). Genetic and environmental effects on secondary sex traits in guppies (Poecilia reticulata). Journal of Evolutionary Biology, 18, 35-45.

Hulse, F.S. (1967). Selection for skin color among the Japanese. American Journal of Physical Anthropology, 27, 143-156.

Jablonski, N.G., & G. Chaplin. (2000). The evolution of human skin coloration. Journal of Human Evolution, 39, 57-106.

Kayser, M., F. Liu, A.C.J.W. Janssens, F. Rivadeneira, O. Lao, K. van Duijn, M. Vermeulen, P. Arp, M.M. Jhamai, W.F.J. van Ijcken, J.T. den Dunnen, S. Heath, D. Zelenika, D.D.G. Despriet, C.C.W. Klaver, J.R. Vingerling, P.T.V.M. de Jong, A. Hofman, Y.S. Aulchenko, A.G. Uitterlinden, B.A. Oostra, & C.M. van Duijn. (2008). Three genome-wide association studies and a linkage analysis identify HERC2 as a human iris color gene. The American Journal of Human Genetics doi:10.1016/j.ajhg.2007.10.003

Kirkpatrick, M. (1987). Sexual selection by female choice in polygynous animals. Annual Review of Ecology and Systematics, 18, 43-70.

Kleisner, K., T. Kočnar, A. Rubešova, and J. Flegr. (2010). Eye color predicts but does not directly influence perceived dominance in men, Personality and Individual Differences, 49, 59–64.

Liberton, D.K., K.A. Matthes, R. Pereira, T. Frudakis, D.A. Puts, & M.D. Shriver. (2009). Patterns of correlation between genetic ancestry and facial features suggest selection on females is driving differentiation. Poster #326, The American Society of Human Genetics, 59th annual meeting, October 20-24, 2009. Honolulu, Hawaii.

Mather, F., J.T. Manning, & P.E. Bundred. (unpublished). 2nd to 4th digit ratio, hair and eye colour in Caucasians: Evidence for blond hair as a correlate of high prenatal oestrogen.

Makova, K, & H. Norton. (2005). Worldwide polymorphism at the MC1R locus and normal pigmentation variation in humans. Peptides, 26, 1901-1908.

Olendorf, R., F.H. Rodd, D. Punzalan, A.E. Houde, C. Hurt, D.N. Reznick, & K.A. Hughes. (2006). Frequency-dependent survival in natural guppy populations. Nature, 44, 633-636.

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Rana, B.K., D. Hewett‑Emmett, L. Jin, B.H.-J. Chang, N. Sambuughin, M. Lin, S. Watkins, M. Bamshad, L.B. Jorde, M. Ramsay, T. Jenkins, & W-H. Li. (1999). High polymorphism at the human melanocortin 1 receptor locus. Genetics, 151, 1547‑1557.

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China and interesting times ...

In North America and Western Europe, the past forty years have seen a radical shift in the marriage market. Before, there were too few single men, particularly past the age of 25. Now, there are too many at all reproductive ages … and even beyond.

A similar shift has occurred in East Asia, in part for similar reasons. First, with the dramatic reduction in male mortality, especially male infantile mortality, the sex ratio at birth (normally 105 boys per 100 girls) now persists to 50 years of age and beyond. Second, with liberal divorce laws, older men can more easily re-enter the marriage market and remarry with younger women. Finally, there is a synergy between these two trends. With many more men living into their 40s and 50s, younger men have to reckon with a source of sexual competition that never existed before.

But East Asian societies face another reason for the steady rise in the ratio of single males to single females: a higher sex ratio at birth. To begin with, this ratio seems naturally higher among East Asians, i.e., in the range of 107 males / 100 females. As elsewhere, this higher ratio is now lasting well into adulthood.

To make things worse, the sex ratio at birth has been steadily rising in some East Asian countries because many parents are now using ultrasound technology to abort female fetuses. In China, this ratio has risen from 1.07 in 1980 to 1.18 in 2005 (Poston & Zhang, 2009). Similar increases have been reported from South Korea and Taiwan (Hudson & Den Boer, 2002).

The result? A worsening wife shortage throughout much of East Asia. With not enough prospective brides in their home countries, more and more East Asian men are looking elsewhere. In South Korea, international marriages rose from 4.8% of all marriages in 2001 to 13.6% in 2005. In Taiwan, the rise has been even more dramatic: 32% of all marriages in 2003.

Unlike the situation in North America and Western Europe, governments are recognizing this problem as something to be dealt with and not simply ignored:

In both Korea and Japan, there is concern to maintain ethnic homogeneity, which leads to a basically conservative stance by the government with regard to international marriages, but at the same time in both countries, there are groups of men who are seen to be missing out in the domestic marriage market (in particular, the low educated, and farmers in certain regions of the country) who are seen to require assistance in finding brides internationally. The end result is interesting: the promotion in Korea of marriages between Korean farmers and Korean Chinese women who, although foreigners, are at least of the same ethnicity […]; the involvement, in Japan, of local government in mail order bride programmes in areas such as rural northern Honshu where there was a perceived crisis in the marriage market … (Jones & Shen, 2008)

East Asian governments thus tend to promote international marriage while ensuring that the brides-to-be are physically and culturally similar to their own populations. Unfortunately, the pool of ethnically similar women lies almost entirely in China, which itself is facing a wife shortage. In the not-so-distant future, the Chinese government will probably halt this emigration, or it will simply dry up of its own accord.

What then? Will East Asian governments allow their bachelors to look farther afield? Or will they attack the problem at its source? Will they start paying women to have daughters in order to bring the sex ratio back to parity?

In this, China is in the worst situation. On the one hand, it has the most unbalanced sex ratio in East Asia. On the other, its bachelors are poorly positioned in the international marriage market, since they earn much less money than do bachelors in South Korea, Taiwan, and Japan. Where can they go to find wives?

The most likely place seems to be sub-Saharan Africa, with Ethiopia being especially likely. With their relatively light skin and fine features, Ethiopian women seem to be the most attractive candidates. Chinese entrepreneurs are also well established in that country. This topic came up on an online thread about Chinese-Ethiopian marriages. One Chinese commenter wrote:

In China the Ethiopian women is revered as a Holy God. Every day we say prayer that God will send us an Ethiopian woman for marriage so that our children are smart, beautiful, and clever like Ethiopia.

Two Ethiopian commenters added:

Nice.. Heheh but i think Ethiopian woman date chinese. If you go and see Ethiopia, many chinese dating Ethiopian.... :)

Overall, considering the shortage of brides in China, I am all for Sino Ethiopian pact to have as many intermarriages as possible.

If the example of South Korea and Taiwan is any indication, African bride immigration to China should increase exponentially and level off only when the ‘market’ reaches saturation. And remember: China has 29-33 million young surplus males (Hudson & Boer, 2002). Bachelors tend to look for foreign wives when they have friends and acquaintances who have already gone this route, i.e., the ‘effect of example’. There is thus a strong potential for exponential growth with no immediate limit, other than the limits imposed by the Chinese government.

And it’s unlikely that the Chinese government will impose any. First, any restrictive legislation would be seen as being racist by a continent that supplies a growing share of China’s raw materials. Second, the Chinese government tends to see international marriages positively, both as a form of ‘soft power’ to increase influence abroad and as a way to reduce discontent among young Chinese bachelors.

Thus, in the near future, we may see the emergence of a partly African minority in China, numbering perhaps in the tens of millions. This is all the likelier because the African brides will tend to have higher fertility than native Chinese women. Of course, the Chinese government could step in to enforce the 1-child policy, but this policy is only weakly enforced now and any efforts to toughen enforcement would be perceived as being racist … not only by the couples involved but also by China’s suppliers of raw materials.

With China being constrained by the dictates of the global marketplace, in this and in other areas of domestic policy, we may eventually see a nasty reaction against globalization that pits the Chinese people against their government and their increasingly globalist business class. At the very least, China will enter a social environment where racism and colorism are real day-to-day concerns, and not simply theoretical ones.

References

Hudson, V.M. & A.D. Boer. (2002). A surplus of men, a deficit of peace. Security and sex ratios in Asia’s largest states, International Security, 26, 5-38.

Jones, G. & H-H. Shen. (2008). International marriage in East and Southeast Asia: trends and research emphases, Citizenship Studies, 12, 9-25.

Poston, D.L. & L. Zhang. (2009). China’s unbalanced sex ratio at birth : how many surplus boys have been born in China since the 1980s? in J.D. Tucker & D.L. Poston (eds.) Gender Policy and HIV in China, The Springer Series on Demographic Methods and Population Analysis 22.

When is the tipping point?

Blue = more men than women, Red = more women than men
US Census Bureau's 2006 American Community Survey, marital status by sex and age.

Over the past forty years, there has been a remarkable flip-flop in the ratio of single males to single females, particularly in the reproductive age bracket. Beginning in the late 1970s and early 1980s, this ‘operational sex ratio’ slipped from male scarcity to parity and then to a relative excess of males, due to a decline in male mortality and an increase in divorce and remarriage by older men with younger women (Pedersen, 1991). The imbalance seems to have steadily worsened. In Germany, single men now outnumber single women up to the age of 60 (Glowsky, 2007). In England and Wales, the latest statistics show that the tipping point has inched up to the age of 75:

But good news is on the horizon. Figures show a growth in the pool of potentially eligible men — now they may end up being the ones doing the chasing. There are more single men in England and Wales than the total number who are married, divorced or widowed for the first time since comparable records began in 2002.

Single men outnumber unmarried women in every age group apart from the over-75s, according to the official statistics on marriage, published yesterday. (source)

The imbalance is even worse (or better, from the above journalist’s viewpoint) if we look only at childless singles. And then there’s the rising incidence of polygyny among ostensibly ‘single’ people …

What about the United States? Jonathan Soma has created an interactive map that shows the operational sex ratio by city and by age group. In the 18 to 29 group, single men clearly dominate (see above map). The tipping point is reached in most East Coast cities with the 35-39 group and in New York with 40-44 year-olds. So shy American males can count themselves lucky. They only have to wait until their late 30s to get married.

Why the difference between the U.S. and England? I suspect the difference lies in the African American and Hispanic American populations. African Americans in particular have a low sex ratio at birth and relatively high male mortality in young age brackets.

Surprisingly, this demographic shift has elicited little comment. I suspect part of the reason is that shy males tend to become computer programmers rather than members of the ‘chattering class’. The latter tend to be … single women.

References

Glowsky, D. (2007). Why do German men marry women from less developed countries? SOEP papers on Multidisciplinary Panel Data Research #61

http://www.dix.de/soeppapers

Pedersen, F.A. (1991). Secular trends in human sex ratios: Their influence on individual and family behavior, Human Nature, 2, 271-291.

Female face shape and sexual selection

Denise Liberton, an anthropologist at Pennsylvania State University, has been studying variation in human facial features. At an upcoming meeting of the American Society of Human Genetics, she’ll be presenting a comparative study of European and West African facial morphology. The main thrust of her presentation is that the shape of the face has differentiated among human populations in part through a selective force that acts primarily on women—and not on both sexes.

We found that several pairwise distances differed between the sexes. For example, the distance from the brow to nasal bridge was found to be more than 5% larger in females than males. We then tested for an interaction between sex and genetic ancestry by testing for differences in the slopes of the ancestry association between males and females. Although the pattern differed slightly between samples, after Bonferroni correction many correlations were the found to be same in both sexes. However, females in all three samples had many additional significant correlations that were not seen in males, while males had very few correlations that were not found in females. The results of these analyses suggest that selection on females is driving the differentiation in facial features among populations. (Liberton et al., 2009)

What is this selective force that acts mainly on female morphology and carries male morphology along in its wake? I suspect Denise Liberton has sexual selection in mind. If so, this finding would support Darwin’s belief that “the races of man differ from each other and from their nearest allies, in certain characters which are of no service to them in their daily habits of life, and which it is extremely probable would have been modified through sexual selection” (Darwin, 1936 [1888], p. 908).

Darwin was puzzled not only by the considerable physical differences separating humans from apes, but also by the considerable physical differences among human populations (Darwin, 1936 [1888], p. 530-531). He concluded that sexual selection was “the most efficient” cause of this differentiation (Darwin, 1936 [1888], p. 908).

Yet sexual selection usually acts on males in other mammals. The females are the ones who normally do the selecting. This is because they must take time out from the mate market for pregnancy, breastfeeding, and infant care. Meanwhile, the males never really leave the mate market, with the result that too many of them are competing for a limited number of available females.

This mammalian ‘law’ has influenced much writing about sexual selection in humans. According to Naomi Wolf, author of The Beauty Myth, "for women to compete with women through 'beauty' is a reversal of the way in which natural selection affects all other mammals" (Wolf, 1990, p. 3). She points to indigenous peoples in sub-Saharan Africa, Australia, and New Guinea as proof that the original human state was one of males vying for the attention of females.

I could cite other writers, but the gist of their argument is always the same. Authentic human nature is represented today by indigenous tropical peoples. They are what we were. Therefore, human nature is about polygynous males who devote little time and energy to raising their progeny and a lot to seducing the limited number of females. Women are thus the ones who have been sexually selecting.

In this kind of argument, we means ‘people of non-tropical origin,’ particularly those of European descent. Yet clearly this argument is false. We were not them for a long time. Europeans have an evolutionary history going back some 35,000 years on their continent. And this was when and where they evolved their current physical appearance: the shape of their face, the color of their skin, hair, and eyes; the length and form of their head hair. To understand why Europeans look the way they do, we should understand how their environment of sexual selection differed from that of tropical humans.

Ancestral humans were exposed to pressures of sexual selection that varied along a north-south axis. In the tropical zone, women could gather food year-round, thus making the cost of a second wife relatively low. With so many being scooped up, female mates were a limited resource. Too many men had to compete for too few women. The pressure of sexual selection was thus on men, with women being the ones who could pick and choose mates.

This situation reversed as humans moved away from the tropical zone. First, it became costlier for a man to provide for a second wife because women contributed less to the family food supply, the longer winters reducing opportunities for food gathering. Second, male mortality increased relative to female mortality because men had to hunt over longer distances. Together, these two trends resulted in too few men competing for too many women. This was particularly so on continental steppe-tundra, where women had almost no opportunities for food gathering and where men had to hunt wandering herds of herbivores over long distances (Frost, 2006; Frost, 2008).

Because of a geographic accident, i.e., a glacial mass over Scandinavia, it was in Europe during the last ice age (25,000 to 10,000 years ago), specifically on the northern and eastern plains, that continental steppe-tundra reached furthest to the south and covered the most territory during the time of modern humans. And this was when and where Europeans came to look European. They did not change in physical appearance because of climatic adaptation. The cause was a change in the direction and intensity of sexual selection: men were now selecting women, and to a much greater degree than elsewhere.

References

Darwin, C. (1936) [1888]. The Descent of Man and Selection in relation to Sex. reprint of 2nd ed., The Modern Library, New York: Random House.

Frost, P. (2008). Sexual selection and human geographic variation, Special Issue: Proceedings of the 2nd Annual Meeting of the NorthEastern Evolutionary Psychology Society. Journal of Social, Evolutionary, and Cultural Psychology, 2(4), pp. 169-191.
http://www.jsecjournal.com/articles/volume2/issue4/NEEPSfrost.pdf

Frost, P. (2006). European hair and eye color - A case of frequency-dependent sexual selection? Evolution and Human Behavior, 27, 85-103.

Liberton, D.K., K.A. Matthes, R. Pereira, T. Frudakis, D.A. Puts, & M.D. Shriver. (2009). Patterns of correlation between genetic ancestry and facial features suggest selection on females is driving differentiation. Poster #326, The American Society of Human Genetics, 59th annual meeting, October 20-24, 2009. Honolulu, Hawaii.

Wolf, N. (1990). The Beauty Myth. Toronto: Random House.

The new marriage market and the future

High sex ratio cohorts are likely, virtually by definition, to have greater numbers of males who fail outright to establish stable couple relationships. Moreover, the relationships that many males do establish in high sex ratio periods may be tenuous and subject to jealousies, rivalries, and the threat of displacement by other, more highly “qualified” males. (Pedersen, 1991)

When Pedersen wrote the above almost two decades ago, he did not exactly fear the new marriage market of too many men chasing too few women. In fact, his prognosis was largely upbeat. There would be “lower divorce rates”, “greater marital stability”, “enhanced marital satisfaction for women”, “greater commitment by males to procurement of economic resources”, “greater willingness by men to engage in active parenting”, and “increase in fertility”. This generally rosy outlook, however, also included the prospect of increased male violence.

Has time proved Pedersen wrong? Well, he was wrong about the positive outcomes. Perhaps he was wrong here too. Look at regions where too many men chase too few women: East Asia, parts of India and, increasingly, the Western world. These regions generally have stability, order, and low crime rates. Conversely, too few men chase too many women in U.S. inner cities and the former Soviet Union.

But such comparisons may be confounded. Stable, orderly societies also tend to be those that value men and unwittingly seek to increase the sex ratio. One reason why East Asian societies are stable and orderly is that their men are good providers. Because they work and provide for their families, parents want to have as many sons as possible—because a son will take care of them in their old age. Hence the high rate of female feticide.

Similarly, one reason why Western societies are stable and orderly is because they value human life so much, even to the point of imposing restrictions on men that would be considered demeaning in other societies (wearing of seatbelts, regulations on cigarette smoking and alcohol consumption, etc.). Hence the low rate of male mortality.

Still, what evidence is there that high sex ratios do lead to male violence? We see men among us who stay celibate for a long time without endangering public order. There is the lifelong bachelor who leads a quiet productive life. There is the immigrant who remains single for 10 to 20 years while he saves up money, buys a home, and builds up his business.

These examples, however, differ on one point from the new society we’re entering—where over a third of all men will be frozen out of marriage and fatherhood. In the past, a lifelong bachelor was often a self-selected individual with a low sex drive and probably low testosterone levels. As for the immigrant who stays single for 10 to 20 years, he would eventually bring out a wife from the old country—typically 10 to 20 years his junior. Neither example violates the social contract we once offered young men: work hard, obey the law, and you will become a full-fledged member of society.

The problem begins when this social contract is no longer honored. Consider China, where the sex ratio has progressively risen since the mid-1980s—after the adoption of the one-child policy and the advent of prenatal sex testing. Today, 97% of all unmarried Chinese aged 28-49 are male. These men make up 72-75% of a large floating population that numbers between 100 and 150 million (Hudson & Boer, 2002, p. 29). Variously described as ‘migrants,’ ‘transients,’ or ‘bare branches,’ they account for a disproportionate share of crime, especially violent crime:

In Beijing, 44% of the crimes solved by the police were committed by transients. In Shanghai, this rate has been continually rising from 10% in the mid-1980s to 60%, even 80% in some districts, by 1995. … Moreover, our study found that many crimes committed by transient people are senseless and ruthless. An argument over a word can lead to a cold-blooded fight; burglars often kill the victims or witnesses on the scene if the offense is observed; highway robbery, rape, and kidnapping usually end with the victims’ death; and a complaint about the poor quality of goods sold by transient vendors can cause injury in a severe physical assault. (Hudson & Boer, 2002, p. 32)

A similar trend has appeared in the northwestern states of India, where sex ratios have reached particularly high levels:

Indeed there is a statistically significant relationship between violent crime rates and the sex ratio in Indian states. Sen notes that “extensive interdistrict contrasts … show a strong—and statistically very significant—relation between the female-male ratio in the population and the scarcity of violent crimes.

… The strongest correlation found was between murder and sex ratio, which were inversely related. As the authors note, “This correlation is very robust: no matter which other variables are included or excluded from the regression, we found that the female-male ratio remained highly significant, always with a negative sign. Further, the size of the coefficient of the female-male ratio is quite large” (Hudson & Boer, 2002, pp. 34-35)

Hudson and Boer (2002) argue that an excess of males increases not only violent crime and internal instability but also the probability that a country will go to war. For the government, war helps ease the tensions created by having too many single men, if only by killing them off. For a single man, war is a chance to enhance his social status and improve his access to women.

… the worst-case scenario implies that China may have close to 40 million young adult bare branches to spare in twenty years, and that the government may at that point ardently wish to see them give their lives in pursuit of a national interest. The alternative is to allow them to remain a threat to national interest, which may increasingly be seen as an untenable policy position by the government (Hudson & Boer, 2002, pp. 36-37)

Another scenario is that China will export single males and import single females. In recent years, a popular destination for Chinese emigrants has been Africa, partly because of its lax immigration laws and partly because of its wealth of undeveloped raw resources. This Chinese diaspora is estimated to range in size from 500,000 to 750,000 (Mohan & Kale, 2007). To the extent that single males take this route, there will inevitably be intermarriage that may alter China demographically when they go home.

Such a scenario may resemble what is already happening in South Korea, where 13.6% of all marriages now involve foreign brides (Lee et al., 2006). At first, these brides were largely ethnic Koreans from China. Preferences are now shifting toward Southeast Asians:

Another 18 percent of foreign wives are from other Asian countries, especially Vietnam, the Philippines and Thailand. According to one international marriage agency, provincial bachelors prefer Southeast Asian women despite their darker skin (racial differences are still subject to stares and comment here, as any expatriate knows) because ethnic Korean women from China have acquired a reputation of melting away into the cities to work after using their new husband only to get a visa. (source)

In one rural county, 3 out of 10 marriages are with foreign women, mostly Southeast Asians. Likewise, a growing proportion of school-age children are of mixed origin:

In North Jeolla province there are 755 biracial students, 700 in elementary schools, 44 in middle schools and 11 in high schools. Four out of eight new students entering Mupung Elementary School in Muju next year are biracial. (source)

Some projections suggest that children of mixed parentage will account for 30% of South Korean births by 2020 (Wikipedia – Immigration to South Korea).

This trend has not gone unnoticed in the ‘other’ Korea. The North Korean press has recently condemned it as “an unpardonable bid to negate the homogeneity of the nation, make South Korea multiracial and Americanize it.” (source)

Both of these trends will probably spread to China, i.e., growing numbers of international marriages and increasing nationalist opposition. That country has an even worse gender imbalance and has adopted the same Western ethos of autonomous individuals being free to pursue their own happiness—even when such pursuits impose costs on everyone else.

The main difference is that China’s standard of living is lower than South Korea’s. Chinese bachelors will probably look for wives in even poorer places, particularly Cambodia, Indonesia, and Africa.

References

Hudson, V.M. & A.D. Boer. (2002). A surplus of men, a deficit of peace. Security and sex ratios in Asia’s largest states, International Security, 26, 5-38.

Lee, Y-J., D-H. Seol, & S-N. Cho. (2006). International marriages in South Korea: the significance of nationality and ethnicity, Journal of Population Research, November 1, 2006.
http://www.accessmylibrary.com/article-1G1-170018371/international-marriages-south-korea.html

Mohan, G., & D. Kale. (2007). The invisible hand of South-South globalisation: Chinese migrants in Africa, A Report for the Rockefeller Foundation prepared by The Development Policy and Practice Department, The Open University, Milton Keynes, MK7 6AA, UK
http://asiandrivers.open.ac.uk/documents/Rockefeller%20Report%20on%20Chinese%20diasporas%2010th%20Oct%20_3_.pdf

Pedersen, F.A. (1991). Secular trends in human sex ratios: Their influence on individual and family behavior, Human Nature, 2, 271-291.

Young men in a sellers market

Except for frontier areas, single women used to outnumbered single men on the American marriage market. This situation has reversed since the late 1970s and early 1980s because of falling male mortality and the rising numbers of older men divorcing and remarrying (Pedersen, 1991). Similar reversals have occurred throughout the Western world.

In this new environment, more women are hesitating to commit, knowing that the penalty of being ‘left on the shelf’ is much less than before. Many, in fact, are playing the market and postponing marriage as late as possible. One result is a rising age of first marriage—almost 30 in most Western countries.

Because people are getting married later, the ratio of single men to single women under 30 looks almost balanced. This near-parity has lulled some writers, like Glowsky (2007), into thinking that intense competition for women is a problem only for middle-aged men. Actually, single men under 30 face even fiercer competition. Using age-preference data, Ni Bhrolchain and Sigle-Rushton (2005, pp. 44, 46) have estimated that two single men are competing for each single woman at the youngest ages:

… Among men, average partner supply is 0.4 at age 17, reaches and goes above 1.0 at around 30 in the US and at 45 in England and Wales (though also, briefly, at age 30) and then rises to 2.0 (US) and 1.6 (E&W) by age 60. On these estimates, a 50-year-old American man had around the same number of potential partners as an American woman of 20 in 1990 ....

… In pure demographic terms, then, and taking these figures at face value, men and women of the same age encounter quite dissimilar levels of partner supply at most ages. In 1990-91, average availability for women far exceeds that for men at younger ages and the reverse is true at older ages. In both countries [United States and Great Britain] in 1990-91, unmarried women aged 20-24 had between 34% and 163% more potential partners on average than did men, and those aged 25-29 between 8% and 28% more.

It might be argued that these estimates overstate the gender imbalance. After all, some young men are uninterested in female companionship because they’re asexual, homosexual, or psychologically immature. This objection was tested by Ni Bhrolchain and Sigle-Rushton (2005, p. 53) through a survey of dating agency clients:

If men experience partner shortages at the prime ages of male marriage, we would expect to find young men over-represented in the dating agency client population. This is indeed the case. Between ages 21 and 40 the age-specific sex ratio among Dateline clients is between 1.4 and 2.6, compared with sex ratios of between 1.1 and 1.3 among the unmarried in England and Wales in 1996.

The new ‘seller’s market’ contrasts with what young men used to face as recently as the early 1970s. Yet this change in fortune has triggered few alarm bells among the commentariat. How come? One reason is that many people blame the sexual revolution of the 1960s on that era’s low ratio of single men to single women. The argument is that a surplus of single women makes men sexually irresponsible. To ensure stable families, we therefore need a surplus of single men. Such a surplus would not make women sexually irresponsible, since women are naturally inclined to form stable, long-lasting relationships.

This view was notably advanced by Pedersen (1991). He predicted that the recent shift to a higher sex ratio among singles would mean less divorce, less illegitimacy, less marital instability, higher birth rates, and greater commitment by men to getting an education and pursuing a career. These presumed benefits caused many, particularly on the political right, to see the new marriage market as a godsend. As recently as 2004 the Wall Street Journal ran an opinion piece that praised the wife shortage and its beneficial influence on the American family (Wilson, 2004).

There is another reason for the complacency of the commentariat. Singleness is a topic where older women do most of the talking and writing. For them, the man shortage is what really matters.

That the adverse marriage market position of young men has been overlooked may be due to the traditional tendency in demography to examine mainly female marriage and partnership. One author pointed to the marriage market difficulties of older women as being the “real” marriage squeeze (Veevers 1988), but in doing so ignored the partner shortages experienced by young men — an issue of greater demographic significance since it occurs at and before the prime ages of male marriage. Davis and van den Oever (1982) suggest that the surplus of unmarried men at young ages is of little importance since most will ultimately marry. (Ni Bhrolchain & Sigle-Rushton, 2005, pp. 59)

From a broader societal viewpoint, we should worry more about the lack of wives for younger men under 35 than about the lack of husbands for older women over 45. The latter are no longer able to have children and are simply seeking companionship. In contrast, the former risk being denied not only companionship but also a role in reproduction.

References

Glowsky, D. (2007). Why do German men marry women from less developed countries? SOEP papers on Multidisciplinary Panel Data Research #61
http://www.dix.de/soeppapers

Ni Bhrolchain, M. & W. Sigle-Rushton. (2005). Partner supply in Britain and the U.S. Estimates and gender contrasts, Population, 60, 37-64.

Pedersen, F.A. (1991). Secular trends in human sex ratios: Their influence on individual and family behavior, Human Nature, 2, 271-291.

Wilson, J.Q. (2004). Sex Matters. Will too many boys make China and India aggressive militarily? The Wall Street Journal, Tuesday, July 13, 2004
http://www.opinionjournal.com/la/?id=110005345