The Skin We are In: The Biology and Social Costs of Skin Color

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The Skin We are In: The Biology and Social Costs of Skin Color

We are united, and divided, by our skin color.

Nina G. Jablonski, 2014. Living Color: The Biological and Social Meaning of Skin Color, University of California Press.

Nina G. Jablonski, 2013. Skin: A Natural History, With a New Preface, University of California Press.

Sources:

https://www.youtube.com/watch?v=tbbwA7XhaZ8

https://www.ted.com/talks/nina_jablonski_skin_color_is_an_illusion/transcript?language=en

https://www.ucpress.edu/book/9780520283862/living-color

https://www.ucpress.edu/book/9780520275898/skin

Racism has once again ignited protest and resistances across the world with the tragic death of George Floyd. How come, the skin color, one of the attributes we get after birth, become the base of discrimination and racism? What are the social meanings and consequences of skin color? Why whiteness is considered superior to blackness? Why skin color has inflicted so much sufferings to certain groups of people? How skin color is shaped by biological force? How the mass migration and fast urbanization influence the change of skin color?

We can raise many questions about the skin color from the perspectives of biology, anthropology, sociology, evolution and medicine. One of the best scholars to consult is probably professor Nina G. Jablonski. She is an American anthropologist and palaeobiologist, known for her research into the evolution of skin color in humans. She is an Evan Pugh University Professor at The Pennsylvania State University, and the author of the books Skin: A Natural History, and Living Color: The Biological and Social Meaning of Skin Color.

Here is a note I take from her book, Living Color: The Biological and Social Meaning of Skin Color, and one of her talks, The Cost of Color: The Health and Social Consequences of Skin Color for People Today at UC Berkeley in 2017, and her TED talk, Skin Color Is an Illusion.

We are united, and divided, by our skin color. Perhaps no other feature of the human body has more meaning. Our skin is the meeting place of biology and everyday experience, a product of human evolution that is perceived within the context of human culture. An attribute shaped by biological forces, skin color has come to influence our social interactions and societies in profound and complex ways. Its story illustrates the complex interplay of biological and cultural influences that defines and distinguishes our species.

My goal in writing this book, Living Color: The Biological and Social Meaning of Skin Color, is to share information on the origin and meanings of skin color and the ways it affects our daily lives.

The first part of the book (chapters 1 – 6) is devoted to the biology of skin color: how skin gets its color, how skin pigmentation evolved, and what it means for our health. Our skin reveals the combined action of the major forces of evolution, from the mutations that provide the basis of variation to natural selection and the other genetic mechanisms that caused changes in skin color as humans migrated around the globe. Every human being represents a walking set of compromise solutions worked out by evolution in the history of our lineage. Skin is our largest interface with the world, and its structure and color beautifully illustrate the concept of conflict resolution through evolution.

The second part of the book (chapters 7–15) is devoted to how we perceive and deal with the social ramifications of skin color. We notice one another’s skin because we are visually oriented animals, but we are not genetically programmed to be biased. Over time, however, we have developed beliefs and biases about skin color that have been transmitted over decades and centuries and across vast oceans and continents.

Skin color has been the primary characteristic used to assign people to different “races.” These categories, which have always been ill defined, have varied tremendously from one place to another. Races have been defined as collectives of physical traits, behavioral tendencies, and cultural attributes. They have been considered real and immutable, so that a person having a particular physical characteristic had, by definition, all of the other attributes of the racial category.

Roger Sanjek, one of the foremost scholars of race, notes that the global racial order has always included more than just black and white, but these two terms and the social values affixed to them have defined its poles. Systems of racial classification built on skin color and other characteristics have varied from place to place and through time. They are the products of racist ideologies. The aim of these classifications has been not only to physically distinguish one group from another but also to rank these groups in hierarchies of intelligence, attractiveness, temperament, morality, cultural potential, and social worth.

The association of color with character and the ranking of people according to color stands out as humanity’s most momentous logical fallacy. While widely recognized as malignant, color-based race hierarchies are still treated as facts of nature by some and are duly upheld and promulgated. A large portion of this book explores the origin and ramifications of this powerful social deception and the many ways in which it has played out in human history. Much is said today about a  “color-blind” society and movement toward a “ postracial” era, but we are not there yet.

In most of the world, darker-skinned people experience prejudice. Despite laws prohibiting color- and race-based discrimination in many countries, many people aspire to lighter skin in order to have a chance at a better life. Understanding all of the different meanings of skin color in our lives may help us as a species eventually to move beyond skin color as a label of human worth and to see it instead as a product of evolution that once caused great misery.

The biology of skin color

There was a fundamental relationship between the intensity of ultraviolet radiation and skin pigmentation. And that skin pigmentation itself was a product of evolution. And so when we look at a map of skin color, and predicted skin color, as we know it today, what we see is a beautiful gradient from the darkest skin pigmentations toward the equator, and the lightest ones toward the poles.

The earliest humans evolved in high-UV environments, in equatorial Africa. The earliest members of our lineage, the genus Homo, were darkly pigmented. And we all share this incredible heritage of having originally been darkly pigmented, two million to one and half million years ago.

Now what happened in our history? Let's first look at the relationship of ultraviolet radiation to the Earth's surface. In those early days of our evolution, looking at the equator, we were bombarded by high levels of ultraviolet radiation. The UVC, the most energetic type, was occluded by the Earth's atmosphere. But UVB and UVA especially, came in unimpeded. UVB turns out to be incredibly important. It's very destructive, but it also catalyzes the production of vitamin D in the skin, vitamin D being a molecule that we very much need for our strong bones, the health of our immune system, and myriad other important functions in our bodies.

So, living at the equator, we got lots and lots of ultraviolet radiation and the melanin -- this wonderful, complex, ancient polymer compound in our skin -- served as a superb natural sunscreen. This polymer is amazing because it's present in so many different organisms. Melanin, in various forms, has probably been on the Earth a billion years, and has been recruited over and over again by evolution, as often happens. Why change it if it works?

So melanin was recruited, in our lineage, and specifically in our earliest ancestors evolving in Africa, to be a natural sunscreen. Where it protected the body against the degradations of ultraviolet radiation, the destruction, or damage to DNA, and the breakdown of a very important molecule called folate, which helps to fuel cell production, and reproduction in the body. So, it's wonderful. We evolved this very protective, wonderful covering of melanin.

But then we moved. And humans dispersed -- not once, but twice. Major moves, outside of our equatorial homeland, from Africa into other parts of the Old World, and most recently, into the New World. When humans dispersed into these latitudes, what did they face? Conditions were significantly colder, but they were also less intense with respect to the ultraviolet regime.

So if we're somewhere in the Northern Hemisphere, look at what's happening to the ultraviolet radiation. We're still getting a dose of UVA. But all of the UVB, or nearly all of it, is dissipated through the thickness of the atmosphere. In the winter, when you are skiing in the Alps, you may experience ultraviolet radiation. But it's all UVA, and, significantly, that UVA has no ability to make vitamin D in your skin.

So people inhabiting northern hemispheric environments were bereft of the potential to make vitamin D in their skin for most of the year. This had tremendous consequences for the evolution of human skin pigmentation. Because what happened, in order to ensure health and well-being, these lineages of people dispersing into the Northern Hemisphere lost their pigmentation. There was natural selection for the evolution of lightly pigmented skin.

Skin tones vary according to levels of UVR and are darker near the equator and lighter toward the poles. The gradient is more obvious in the Old World and less so in the New World, where people have lived for only about 10,000 to 15,000 years. Illustration © Mauricio Antón 2011.

The social meaning and consequences of skin color

There have never been any “pure” human populations or races. Archaeological and genetic evidence show us that during Neolithic times (roughly 10,000–3000 BCE), considerable intermingling of populations occurred. This was mostly a gradual ebbing and flowing of people according to changes in weather and climate and the introduction of agriculture and growth  of  populations.  This  mixing  resulted in human populations on all continents being mutts and mongrels, some more so than others.

From the fifteenth century onward, abrupt encounters between different populations became frequent as seafarers, explorers, and traders in modern sailing boats came into contact with people on distant shores. These meetings often brought together people not only of different skin colors but also of different languages, cultures, and habits. Skin color nonetheless emerged as the most salient characteristic, around which stereotypes coalesced. More than anything else, it signified otherness.

Preliminary voyages and meetings matured into regular trading routes and associations. Some of these involved the mutual exchange of lucrative objects, but most involved highly asymmetrical relationships in which one side benefited inordinately at the expense of the other. At first, humans constituted a small fraction of trade objects, but by the mid-fifteenth century slaves had become commodities essential to the emergence and growth of modern commerce.

The negativity of stereotypes associated with African slaves increased over time. Black and white polarities of color and morality were reinforced and biblical justifications invoked to render the dark-skinned less than human and defend their continued exploitation as slaves. The European intelligentsia contributed to these attitudes by supporting the development of schemes of human classification that ranked the peoples of the world by skin color, cultural potential, and social worth.

Races were born from this urge to categorize. Created by men considered to be intellectual leaders, races were defined as authoritative categories. Skin color was the essential characteristic that gave a race its social valence and established its place in an explicit hierarchy.

The ordering of races according to skin color has been one of the most stable intellectual constructs of all time, even though the number, inclusivity, and acceptability of racial categories have varied greatly. Races are socially constructed and regularly reconstructed. Because they have become institutional facts, races have persisted along with the implicit hierarchies from which they arose. When people persist in acting on their beliefs about race, they maintain a society in which access to the goods of society—such as quality education, high-status jobs, good housing, and good medical care—is stratified by race. Race becomes a destination, not just a label. Perpetuation of the false idea that races represent real biological entities promotes the notion that racial inequities are acceptable and lessens the interest of people in interacting with those placed in racial out-groups.

Skin We are In

There is no topic more illustrative of human history than skin color. It unites us in evolution and divides us by walls of bias and stereotype. It invites us to learn about the life and times of our distant ancestors and taunts us with evidence of the psychological manipulation of modern peoples.

Skin and skin pigmentation were intensely influenced by evolutionary processes for hundreds of thousands of years of human evolution because skin, and skin alone, was our interface with the environment. Variation in human skin pigmentation was produced by evolution, and the processes by which this variation came about are well understood. Different skin tones evolved as humans dispersed into places with different levels of UVR. Adaptive changes in skin color depended first on the occurrence of random mutations to produce the genetic variation necessary to change skin pigmentation and then on natural selection   to make those mutations the norm. The melanin that imparts color to human skin is an excellent natural sunscreen that protects the body from the most destructive effects of UVR while allowing some of this radiation to penetrate and stimulate vitamin D production. The degree of melanin pigmentation in the skin is thus an exquisite evolutionary compromise.

For most of human history, people’s skin pigmentation was well matched to their varying environments. Dark pigmentation protected people living in places with high UVR, and varying degrees of depigmentation allowed people to live healthily by enabling vitamin D production even in places with moderate or low levels of UVR. This equilibrium has been upset, especially in the past four hundred years, by long-distance travel and indoor lifestyles.

Many people live in places distant from their ancestral homelands and often under UVR conditions dramatically different from those experienced by their ancestors for thousands of years. Mismatches between skin pigmentation and local UVR conditions have led to a host of health  problems.  People with little skin pigment suffer from the effects of too much UVR, and those with considerable melanin pigment suffer from the effects of too little. Now that a working understanding of both of these situations is  at hand, serious health problems like skin cancer, folate and vitamin D deficiency, and the many diseases caused by vitamin D deficiency can be avoided.

Skin color is a lasting statement of our evolutionary history. It is a biological trait—an adaptation to the environment—that has come to have many layers of social meaning. It has continued to be important in human affairs despite laws in many countries prohibiting formal color- or raced-based discrimination.

We understand how skin color evolved, how it is perceived, how it came to be judged, how it came to be associated with other traits in  race categories, and how judgments about it have come to be rigid, collectively reinforced, and spread through time and space. We also know from ancient and recent history that the suffering caused by color-based discrimination has cost millions of lives and, for many, is still acute. The diminishing of a human being on the basis of skin color lays bare the worst aspects of our visual orientation, suggestibility, imitativeness, and status consciousness.

The bodies of understanding we now have about skin color need to be matched by the will to change. This is a process in which no one is a spectator: we are all participants.

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