New History Is More Than Skin Deep
I'm Farai Chideya and this is NEWS & NOTES.
For African-Americans and arguably all Americans, skin color is tied to our history. Of course, skin is more than just a racial concept. Think of beauty, wrinkles, sweat, shine, odor, protection, hair. Let's not forget pimples and all the other concepts associated with skin.
Anthropologist Nina Jablonski has written a new book about the largest organ of the human body. It's called Skin: A Natural History. Welcome.
Ms. NINA JABLONSKI (Author, Skin: A Natural History): Thank you.
CHIDEYA: So you write in your book that a body without skin proves that we're all the same. But without the skin there, there can be no us?
Ms. JABLONSKI: Absolutely. The skin is one of the most underappreciated parts of the body. We take it completely for granted, and it does a variety of wonderful things for us biologically. And as human beings, it does an enormous number of things for us culturally. So it's an amazingly important biological organ and it's an organ of human self-expression.
CHIDEYA: You break things down into different categories. You talk about - one thing I was fascinated by was hair, you know. There was a theory I guess that hair, human hair developed to keep us warm before we had clothes, but you say that's not quite the case.
Ms. JABLONSKI: Well, basically, we can make a very good case for humans, our human lineage having lost most of its functional body hair probably around two million years ago when we became very active bipedal primates in equatorial African environments.
Here we're talking about earliest members of the genus Homo. These were tall, strapping people who basically spent a lot of time in the sun, walking around, foraging, avoiding predators, and they needed to keep cool. It was at that time in human history that we lost most of our functional body hair and became incredibly good at keeping cool through sweating.
CHIDEYA: You spent a lot of your time studying skin color, which is such a loaded topic. On a biological level, what is the significance of skin color? And on a cultural level, what is the significance?
Ms. JABLONSKI: Skin color is probably one of the most fascinating aspects of the way people vary. And it hasn't been studied very much in recent years because it is or it has been such a socially charged topic. But the long and short of it is that skin pigmentation, the amount of skin pigmentation that we have, helps to determine the amount of ultraviolet radiation in sunlight that can penetrate into deep layers of our body. And so the more pigmentation you have, the less ultraviolet radiation can penetrate into your skin.
And basically, darkly pigmented peoples evolved in equatorial environments. We started out as darkly pigmented people. Lighter pigment skin was actually called for because ultraviolet radiation, although it's mostly a very negative and deleterious influence on the body, does one positive thing, which is to help begin the process of making vitamin D in the skin.
Now if you have too much dark pigment in your skin, you greatly slow the process of making vitamin D. And so over the course of thousands of years, as we moved into farther northerly and southerly climbs, we had to evolve more lightly pigmented skin so that our skin could continue to make vitamin D.
It's an absolutely beautiful evolutionary story. Being able to tell the biological story of skin color helps people relax about understanding why they have the skin color they do. They can then deal with the health consequences of their skin color and then deal with the manifold social issues, which you eluded to earlier, that are so important and that are still with us.
CHIDEYA: What about touch? You talk about how touch is an underrated sense I guess somewhat in the way that skin in an underrated organ.
Ms. JABLONSKI: Touch is enormously important, because touch is fundamental to our wellbeing. Although we're highly visual animals, we see each other and we respond to visual cues, we respond in very subtle and important ways to touch. At least gentle, caring, touch helps people to feel soothed and calmed.
Normal touch is really important to the upbringing of children. If children aren't given ample amounts of caring touch, they don't grow properly. They need to be touched in order to feel that they're part of a social unit. Touch is absolutely essential to our wellbeing, to normal child growth and development and to our health as adults.
Although we live in a very touch adverse society and a society in which often touching is followed by litigation unfortunately, touch remains a fundamental importance to our biology and our culture.
CHIDEYA: Nina, thank you so much.
Ms. JABLONSKI: Thank you very much for having me.
CHIDEYA: Nina Jablonski is an anthropologist, and her new book is called Skin: A Natural History.