Growing Up in the Two Koreas

The Korean peninsula at night (google earth)

The above image of east Asia at night is worth more than a thousand words. Below the 38th parallel is the birthplace of my mother-in-law in South Korea, which is luminescent at night as the result of its highly developed economy. My father-in-law was born above that line in North Korea, which today appears to be little more than a shadow of its southern neighbor. Even if one knew nothing about history or geography, they could infer from that single satellite image that there must be a chasm in living standards on either side of the border.

A full history of the two Koreas and the war of 1950-53 is beyond the scope of this post. What is relevant is that the forces of history and politics took a once cohesive nation and cleaved it in two, having disparate effects not only on the ideologies on either side, but also on the physical bodies of the respective inhabitants. It’s almost as if someone collected a population of dandelions from a single field and then placed them in two different greenhouses for six decades, replete with different soil quality, sunlight, and temperatures, and then observed how they fared. By now, many people have heard something about how North Koreans are significantly shorter than their southern cousins, implying that, like our dandelion example, the conditions for physical growth are quite different in the two greenhouses. John McCain even mentioned this during the 2008 presidential debates to illustrate North Korea’s brutality toward its citizens. How true is this claim?

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Inequality, Health Disparities, & Obesity

An October poll of 1,000 likely voters found that Americans are increasingly concerned about income inequality. When asked: “How Big a Problem is Income Inequality in the US?,” the majority (74%) replied that it was either a big problem or somewhat of a problem. Predictably, there were differences in opinion by political ideology, but a majority of liberals (94%), moderates (81%), and conservatives (55%) answered that inequality was at least somewhat problematic. However, as is true of many polls, it was not specified exactly what people found unsettling about it. I suppose there are many reasons that people might find increasing inequality (and climbing rates of poverty) to be troubling, but I wanted to focus here on inequality and health, particularly on obesity.

First, what do we mean by poverty? I remember watching an interview on PBS with the economist Jeffrey Sachs years ago (transcript here – thank you, Google), where he distinguished between two types of poverty. The first was an extreme form, which he called the type of “poverty that kills.” The other type was more of a poverty of inconvenience or jealousy. I don’t want to over-interpret Sachs’ meaning. It was a passing phrase in an interview from ten years ago, and his primary focus was on alleviating the extreme poverty faced by more than a billion people in the world living on $1 per day (see Sachs 2005). Elsewhere, Sachs has lamented that the media have ignored poverty in the United States at a time when “the U.S. has the greatest income inequality, highest per capita prison population and worst health conditions of all high-income countries.” His credentials in fighting poverty are unassailable. But I cite the old interview here because I think his descriptions (‘poverty that kills’ vs. ‘poverty of jealousy’) might resonate with many people today, and not necessarily in a good way.

Extreme poverty: scavenging at a garbage dump in Phnom Penh (abcnews)

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Part 5. Humans are (Blank) -ogamous: Pair-Bonding and Romantic Love

This is the fifth part on the evolution of human mating behavior, comparing evidence for promiscuity and pair-bonding in our species. Please see the introduction here.


One of these days I will wake up – which I think I have done already – and realize to myself that I really do love. I find it very difficult to allow my whole life to rest on the existence of another creature. I find it equally difficult, because of my innate arrogance, to believe in the idea of love. There is no such thing, I say to myself. There is lust, of course, and usage, and jealousy, and desire and spent powers, but no such thing as the idiocy of love. Who invented that concept? I have wracked my shabby brains and can find no answer. (Letter from Richard Burton to Elizabeth Taylor)

“Emotions and motivations (are) hierarchically ordered in the brain. Fear can overcome joy, for example. Jealousy can stifle tenderness…But in this pecking order of basic and complex emotions, background feelings and powerful drives, romantic love holds a special place: close to the zenith, the pinnacle, the top. Romantic love can dominate the drive to eat and sleep. It can stifle fear, anger, or disgust. It can override one’s sense of duty to family or friends. It can even triumph over the will to live. As Keats said, ‘I could die for you.’ ” (Helen Fisher 2004: 97-8)

“Only love can leave such a mark / But only love can heal such a scar.” (Paul Hewson)

Attempting to summarize the evolution of romantic love and pair-bonding in humans is an enormous task. This is exacerbated by many complications: the literature on these topics is vast; the term ‘pair-bond’ has been used in different ways by different primatologists in the past and is often erroneously confused with ‘monogamy’; the neurobiology of romantic love – which is not a prerequisite of pair-bonding – is complex; the question of when/if humans became pair-bonded in our evolutionary history is highly speculative; and then there is the complicating factor of culture. Furthermore, parts two through four in this series addressed ten biological traits indicating that humans have promiscuity built into us to some degree, and that monogamy, or at least lifelong monogamy, does not come easily.

Gibbons (Hylobates lar). From Wikipedia.

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Part 4. Humans are (Blank) -ogamous: Promiscuity & Physiology

This is the fourth part on the evolution of human mating behavior, comparing evidence for promiscuity and pair-bonding in our species. Please see the introduction here.



We left off with a list of eight traits in humans suggesting promiscuity in humans. Admittedly, the previous post was a little thick, as it dealt with imprinted genes and population genetics. The current one concerns human reproductive physiological and anatomical traits consistent with a multiple-partner mating structure, building on a couple of points addressed by Ryan and Jethá in their book. If you’re paying attention, that’s three posts concerning promiscuity and one (yet-to-be-written) on pair-bonding. Perhaps it seems I’m stacking the deck, but please reserve judgment. One reason more space is needed to make the case for the evolution of promiscuity is that the biology is less well known, and more effort is needed to bring it into the light. That single post on pair-bonding will be an important one, and quality matters just as much as quantity.

Continuing on with our list of traits hinting at promiscuity…

9. Sexual dimorphism in body size. This point remains somewhat contentious. In the majority of anthropoid species (monkeys, apes, and humans), males are the larger sex, with the degree of dimorphism ranging from slight to extreme (Plavcan 2001). This pattern correlates strongly with mating structure and male-male competition (Plavcan and van Schaik 1997). For monogamous species like gibbons, males and females tend to be roughly the same size. In species where females prefer larger males or where males compete for access to females, bigger males will leave behind more descendants. This is true for polygynous gorillas and dispersed, territorial orangutans, where males are physically about twice as large as females. A good non-primate example is elephant seals. On the other hand are horseshoe crabs, where smaller males cling to the backs of larger females and wait for the release of her eggs. This ‘reverse dimorphism’ is found in a few primates, but is slight and only in some prosimians such as lorises and lemurs.

Former sumo wrestler Konishiki and his wife Chie Iijima, an obviously cherry-picked example of extreme dimorphism. (From

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Part 3. Humans are (Blank) -ogamous: More on Promiscuity, & Genetics

This is the third part on the evolution of human mating behavior, comparing evidence for promiscuity and pair-bonding in our species. Please see the introduction here.


Part 2 pertained to human behaviors that suggested a human propensity for promiscuity (primate sexuality, the excessive sexual capacity of humans, infidelity rates, cultural variation in marriage practices, number of lifetime sex partners, etc.). This post and the next are concerned more with clues from our genes, anatomy, and physiology suggesting promiscuity. I realize these things are not clearly demarcated. My advisor at Binghamton, Mike Little, liked to say that “biology is behavior, and behavior is biology.” But I think in general most people would agree that while behavior has a genetic component, it is more plastic than are anatomical structures.

We left off with a list of six traits hinting at promiscuity. I don’t want to simply rehash what Ryan and Jethá address, so this post addresses some additional points on genetics before returning to their book in the next submission. Continuing with that list…

Fetal ultrasound at 4.5 months, profile view

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Student Research on War, Health, and Biology

With grades submitted earlier this week, the Spring 2011 semester is officially in the books. In my ANTH 324 class, “A Biocultural Approach to War,” students were required to write a literature review paper on the ways that war impacts human biology and health.

In my opinion, research papers are valuable in upper level undergraduate classes because they give students the freedom to pick a topic of their choice, within the boundaries of class goals. While it seems self-evident that war’s effects on biology are negative, this relationship is not always straightforward for every possible outcome variable. Thus, it is necessary to explore the evidence thoroughly.   

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The Sex Ratio at Birth Following Periods of Conflict

Note: this paper was written by UMass Boston undergraduate student Johnny Xu for my Spring 2011 class ANTH 324: “A Biocultural Approach to War.” I asked his permission to post it here. 


Birth Sex Ratio and Infant Mortality: Adaptations or By-products?


1. Introduction

            The purpose of this paper is to provide manifold reasons attempting to explain why the birth sex ratio following war periods tend to rise in favor of males and what this implies in correlation with infant mortality; and, most of all, to answer the following question: is the combination of these findings proposing that this is an adaptive response of the parent to produce the sex with higher survival prospects in the given environment, or is this simply the by-product of environmental forces?


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