Science Vs - Race: Can We See It In Our DNA?

Episode Date: April 19, 2019

For decades, we've heard that race is a social and cultural idea — not scientific. But with the changing world of genetics, is race science back? We speak to sociologist Prof. Dorothy Roberts, evolutionary biologist Prof. Joseph L. Graves Jr. and psychological methodologist Prof. Jelte Wicherts. Check out the full transcript here: http://bit.ly/2nTDU8w Selected references:  Dorothy’s book on the history of scientific racism One of Joseph’s books unpacking raceThe 2005 paper on population structureA handy FAQ from a population geneticistA paper on the knowns and unknowns about genes and the environment on IQ Credits:  This episode was produced by Rose Rimler, with help from Wendy Zukerman, as well as Meryl Horn and Michelle Dang. Our senior producer is Kaitlyn Sawrey. We’re edited by Blythe Terrell. Fact checking by Michelle Harris, Meryl Horn, and Michelle Dang. Mix and sound design by Peter Leonard. Music by Peter Leonard, Emma Munger, and Bobby Lord. Recording assistance from Botte Jellema and Shani Aviram. A huge thanks to Stillman Brown, Morgan Jerkins, Amber Davis, Cedric Shine, Emmanuel Dzotsi, and to all the scientists we got in touch with for this episode, including Noah Rosenberg, Rasmus Nielsen, Mark Shriver, Garrett Hellenthal, Sarah Tishkoff, Kenneth Kidd, John Protzko, Dan Levitis, and others. Finally, thanks to the Zukerman Family and Joseph Lavelle Wilson.  Learn more about your ad choices. Visit podcastchoices.com/adchoices

Hi, I'm Wendy Zuckerman, and you're listening to Science Versus from Gimlet. To start this episode, we're going back to the year 2000. It's a warm June morning in Washington, D.C., and we're in the White House's East Room, where a press conference is set up. There's an expectation in the air. Everyone stands, and in walks President Bill Clinton. Clinton walks up to the podium and faces a room full of photographers, reporters and scientists.

Behind him on a TV screen is some science-y but very cheesy imagery, a double helix, and the words, decoding the book of life. Good morning. We are here to celebrate the completion of the first survey of the entire human genome. Clinton is announcing that the Human Genome Project had hit its watershed moment

and mapped out the human genome for the first time. Have revealed nearly all three billion letters of our miraculous genetic code. its watershed moment and mapped out the human genome for the first time. Have revealed nearly all three billion letters of our miraculous genetic code. And on that stage, one idea that was front and centre was about race. Race had always been this concept that carried a tonne of weight socially. But did it have any scientific meaning? Well, now, this project had mapped the DNA of five people who had ancestry from across the globe, including Asia, Europe and Africa.

So what did they find? Well, that day in 2000, it was announced that on a genetic level, these people were basically no different. I believe one of the great truths to emerge from this triumphant expedition inside the human genome is that in genetic terms, all human beings, regardless of race, are more than 99.9% the same. One of the lead scientists on the project took the stage and drove this message home. The concept of race has no genetic or scientific basis. There's no way to

tell one ethnicity from one another. So these guys might have thought they were closing the door on the idea that race was 0.1% different. So in the 20 years since this announcement, what has science found out about that tiny bit of difference between us all? Does race live there? Because that's what some people are starting to say. If you're looking at someone from China or you're looking at a man from Kenya, there's something different about them.

So your instinctive understanding is correct. Race is real. These are biological facts. They're not sociological constructs. And this idea that new science shows the races are real, it's taking hold in dark corners of the internet, where white supremacists are using it to make even bigger claims, that genetics proves the white people are the smarter, superior race. Okay, so what's happening here? For centuries, race has been a political and social idea.

But where does science fit into this? Today, we're going to answer the following questions. One, with new science, can we see race in our genetics? And two, if you can, what do those differences mean? Like, could one race be smarter than another? When it comes to race, there are lots of opinions. But then there's science. Yeah, this is actually an area science has messed up for a long time.

We'll tell you about that too. Science vs Race is coming up just after the break. Bumble knows it's hard to start conversations. Hey. No, too basic. Hi there. Still no. What about hello, handsome? Who knew you could give yourself the ick? That's why Bumble is changing how you start conversations.

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I'm Jan 11. I'm Steve Strogatz. And this is... Quantum Magazine's podcast, The Joy of Why. New episodes drop every other Thursday, starting February 1st. Welcome back. Today, we're talking about race and we're asking scientifically, does it exist? And by that, we mean that when you look at our DNA, can you see consistent differences that separate people who are black or white or Asian or what have you. But understanding the science behind race is super complicated and messy, partly because it has this dodgy scientific history.

To tell us about it, we got Professor Dorothy Roberts from the University of Pennsylvania into our office and put a microphone in front of her. Mm-hmm. I have a giant puffy thing in front of my mouth right now. Fuzzy. It's furry. It's furry. And pretty quickly, we got into the history of race and science. Dorothy told us that it really began in the 17th and 18th century in Europe.

It was the Age of Enlightenment. Science in Europe was having a heyday, and scientists were racing to understand the world around them. These typologists were classifying all of nature. They were classifying plants and animals and rocks and other aspects of the natural world. And they included human beings. Colonialism was in full swing. Europeans were sailing to Africa, the Americas, and Asia, and seeing all these people who looked really different to themselves. And so they started to categorize them too.

And this was a particular pastime of this highly respected botanist called Carl Linnaeus. Carl Linnaeus, Swedish typologist, had a very prominent enterprise of classification. Carl slotted people into several categories, including European, African, Asian and Native American. Oh, yeah, and he had some wildcard categories too. Like there was this one called Euenus lupinus or, get this,

wolf boys for children raised by wolves. Really. Weirdly, that one didn't catch on. But what did catch on was some of the descriptions that he and other scientists gave of each race, always giving Europeans the best adjectives.

Here's Dorothy. White people are characterised as beautiful and they're also characterised as the most rational. And black people are described as prone to violence, to laziness, to illness, to mental disorders. Carl also described Asians as severe and haughty, while Native Americans were reddish and obstinate. All through the 1700s and 1800s, scientists ran with these ideas,

claiming that you could see real differences in the bodies and brains of the races. And very quickly, a clear scientific hierarchy was formed, with white people at the top and everyone else underneath them. And all of those scientists thought they were being objective, but we can now see in hindsight that they were being woefully subjective. That's even too mild a term. They were being racist.

And part of the reason these ideas were so powerful was because they were very useful for justifying slavery, as well as colonization more generally. After all, if science says that Africans or Native Americans are a lesser group of people, then it's okay to take their land and enslave them. It made the domination of white people over other people seem as if it was just following what nature had planned. These definitions of the races hung around in the scientific world for a really long time. While some scholars did question them, these ideas were a big part of the eugenics movement, and it wasn't really until the aftermath of the Holocaust that the scientific establishment got together

and said, this idea of a biologically superior white race, it's not science. And then, decades later, we had the Human Genome Project, which came along saying, Human beings, regardless of race, are more than 99.9% the same. So science had done a 180 since Carl Linnaeus, and it was now telling us that race doesn't exist. But there were always these things that didn't seem to make sense to some. Because people can look around and see that we have different skin color, different eye shapes, and different hair.

And so there's no point in denying, because it's absolutely true, that human beings are diverse genetically. Yes, you can see that. You can see that, you know, walking down the street in any big city. And there's another problem too. When Bill Clinton told us, I did not have sexual relations... Oh, sorry, wrong quote. When Bill Clinton told us that the Human Genome Project had showed us that we are 99.9% the same, well, what about that bit that's left over? The problem, though, is that the 0.1% is a lot of genetic variation.

Yeah, this is a lot. 0.1% amounts to around tens of millions of possible changes in our DNA. It's enough to explain the differences in the way we look, because even small genetic changes can have a big effect. Think about pooches. Switch up a teeny portion of doggy DNA and your five-pound chihuahua turns into a 50-pound Siberian husky. So, does the 0.1% leave the race store ajar scientifically? For this, we need to meet Professor Joseph L. Graves,

Jr. He's an evolutionary biologist at North Carolina A&T State University. So I was always attracted to these big questions. The reason evolution hooked me is because it answers the big question. One of the big questions he wanted to answer is, can you see race in the tiny differences in our DNA? Well, when you zoom in on that 0.1%, for the vast majority of that DNA, you can't see anything that looks like race. But for a very small bit of it, it gets complicated.

So to sort it out, we first need a definition of biological race. We figure that for race to exist biologically, you would need to find that people with the same appearance, like the same skin colour, well, they should be a genetically uniform group. So they should be really similar to each other. And they should be different from people with other skin colours. So that is, when you just look at DNA, white people should be more similar to other white people and they should be clearly different to, say, Asian people. And if there are these genetic differences,

then they might map on to racial stereotypes influencing different abilities and behaviours like maybe athleticism or intelligence. So, is this what we see? Let's start with this question of whether people who broadly look the same are genetically similar to each other. Here's one way scientists might try to work that out. What they do is they take a certain number of individuals that are sampled from different portions of the spectrum of human beings.

Then scientists can put the DNA through an algorithm and plug in how many categories they want us to file into. So if I want to see five clusters, the algorithm will give me five clusters. One of the most influential studies that did this looked at around a thousand people and here's what they found. Genetic groups didn't map neatly onto skin color and appearance. So for example, Europeans, whiteys, were clumped together with people from the Middle East, Central and South Asia. There was a group for Africa, but they were in a completely different group from other people with dark skin, like those from Oceania. Joseph told

us he's seen other studies that show this kind of thing, like in these islands way east of Indonesia, the Solomon Islands. So if one, for example, were to take people who live in the Solomon Islands and you would look at their physical characteristics, you would find them indistinguishable from many sub-Saharan Africans. But genetically, Solomon Islanders are actually more closely related to East Asians than they are to sub-Saharan Africans. So that tells us that genetically speaking, if you want to put people into groups with their closest genetic relatives, skin colour is not a scientific way to do it. We also said that for the races to exist biologically, you'd need each race to be pretty genetically uniform. But when you zoom in on that Africa cluster,

you actually see crazy genetic diversity. In fact, Africa is a genetic hotspot, and that's because it's where human beings came from in the first place. One of the things that has been consistently agreed upon with regard to the history of our species is the origin of human beings in sub-Saharan Africa and that those populations have the greatest genetic diversity of all people on this planet. And when you understand why we have differences like skin colour, this idea of grouping us in this way and saying that all whites or all black people

are basically the same kind of people. It doesn't really make sense. You see, humans evolved darker skin to protect us from sun damage. And later, some people got lighter skin to get more vitamin D. So that tells us that skin color is just a simple adaptation to the environment, not necessarily anything else. So if you're a sub-Saharan African, you have darker skin. If you are in the Middle East and you're in the tropics, you have darker skin. If you're in Indochina and live in the tropics, you have darker skin. One can clearly see that, yeah, there are people who are light-complected. And yes, there are people who are dark-complected. But that's about as far as that consistent difference goes. Okay, so natural selection has worked its magic on us

to make us look different. But what about traits that are invisible? Because it feels like for race to be biological, we would need to see stuff that's more than skin deep. We would need to see specific traits that were unique to one race and not the other. Is that what we see? Well, let's start with a simple example, drinking milk. You might have seen white supremacists on the internet getting all amped up about chugging milk to prove their superiority. And now most alarming of all, white supremacists are chugging

milk because for white supremacists, lactose is their only form of tolerance. Milk nationalism now! But actually, lots of people from around the world can drink cow's milk. You can find lactose tolerance in northern Europe, sure, but also in East Asia and parts of the Middle East. And that's because cultures around the world have been domesticating cattle for thousands of years. Long enough to have evolved to chug a cold one. We have geographic variation.

We have adaptation to local conditions, but we don't have really genetically distinct groups. And this is what you'd expect. Humans are newbies on this planet. We're a relatively young species and we just haven't had that much time to accumulate a ton of differences the way that other animals have. We've also never been that separate from each other. For thousands of years, people were having sex with their neighbours or setting off in canoes and having babies in far-flung places. And that's what makes it impossible to define biological races within our species because there simply isn't enough genetic variation

at these regional and continental levels that allow us to unambiguously define groups that we say are different from each other. And so the way we throw around the word race, does it match what geneticists see when they look into our DNA? No, that's not correct. So that's off the table. Evolution didn't read Carl Linnaeus' book and go, perfect, I'll do that. Still though, if we evolved to drink milk or to have a different

skin colour, could the environment have pushed some groups to evolve other, more complicated things? Like maybe intelligence? After the break, we tackle one of the most controversial claims, and it's one that's been getting a lot of attention. It's that science actually shows

that some groups are more intelligent than others. And that is coming up. Welcome back. Today we're exploring the science of race. And we're asking, biologically, does it exist? We've found out that genetics doesn't put people cleanly into boxes. But rather, evolution gave us little pushes into slightly different directions, giving some of us the ability to drink cow's milk

or, say, have a different skin colour. The fact that different groups of people have different genetic mutations thanks to evolution is making some people wonder, could evolution have played a role in bigger things, with bigger consequences? Like maybe our intelligence? Professor Joseph L. Graves Jr. has heard evolutionary stories

as to why some people think this makes sense. That somehow the presence of winter makes you smarter than living in the tropics. The idea here is that people who lived in cold places like northern Europe had to work out how to survive in this hostile environment. So only the smart made it. And over time, they made smarter babies than people who lived where it was warmer, like sub-Saharan Africa.

And Joseph is used to hearing stuff like this. He heard it all through his career. The thing that your listeners probably don't know is I was actually the first African American to ever receive a PhD in my field. And I went through professors who sat in courses and did not think I should be there, and who published the work that attempted to prove that genetically that Africans were inferior to Europeans. And those folks, of course, had a really hard time with me being in their classes and being so good at what I did.

And while Joseph was battling prejudice throughout his career, people who study this kind of thing, the way humans evolved, they haven't dug up anything that suggests this winter idea is true. In fact, we know that people in warm climates kept themselves quite busy coming up with amazing things like maths and agriculture. But this question of is one group more intelligent than another, it's one that we felt we had to look further into because it's gotten a lot of attention recently

from a number of high-profile people. And they're saying science suggests that white people are smarter than black people. It's folks like Nobel Prize winner James Watson, science writer Nicholas Wade, and podcaster Sam Harris. Here he is. People don't want to hear that intelligence is a real thing

and that some people have more of it than others. And they certainly don't want to hear that average IQ differs across races and ethnic groups. Now, for better or worse, these are all facts. Facts? Okay, so these people are saying this controversial thing. And they say that the proof that whites are smarter lies in IQ tests. Okay, these guys want to play in the science sandbox?

Let's see how they go. Science Versus producer Rose Rimler and I called up an IQ expert. My name is Jelte Wicherts. Wicherts. It's Jelte Wicherts. Wicherts. It's very close. Wicherts. Jelte Wicherts.

Wicherts, yes. Wicherts. Wicherts. Just add the S and you're in a good place. Jelte is a professor of psychological methods at the University of Tilburg in the Netherlands. So we asked him, straight off, when you compare blacks and whites, who does better on IQ tests? So whites on average perform better. How large is the difference? So in IQ testing, the data appear to point at least 10 IQ points between African-Americans and white Americans.

While there will always be whites who get terrible IQ scores and black people who do really well, studies have found that on average, African-Americans score about 10 points lower than European-Americans. Yeah, it's a big gap. And it's important to know that psychologists do take IQ tests seriously. We do know that IQ scores predict an awful lot of things. So we know that IQ at a young age predicts how well people do in school, how many years of education they will

eventually obtain. IQ predicts also how well people do in different types of jobs. People tend to have the same IQ scores over the course of their life, which is why scientists like Yelter say that IQ tests really can tell us something worthwhile. Given that these tests aren't rubbish and European Americans tend to do better on them, what does that mean? Does that mean that white Americans are inherently smarter than black Americans? Now, you can't say that. There's a distinction between the IQ scores and the thing that we're trying to measure, namely intelligence.

What Yelta means is that even though IQ tests can tell us a lot about who's going to be successful, they're not necessarily measuring innate, true intelligence. And that's because there could be things that affect some people's scores outside of their smarts. Some argue that these tests are biased. That is, they're typically written by white people who might have unintentionally included questions

that are easier for white people to answer. And this is actually what Yelter researches. So we asked him if it's true, if the tests are biased. We don't know. Some do show that the tests are fair, but others also hint at some biases. And something we've found frustrating is that we've seen people online

cherry-picking the work of Yelter and others, pointing just to the findings that suggest these tests are fair and unbiased, meaning to them whites truly are smarter. So I asked him about it. Some people use your work and your research to say that whites have genes that make them smarter than blacks. Is that what your work says? I'm not aware of any of my papers that actually said that or showed that in a particular way. It just shows that people have their opinions made up and then are very well equipped, even if they're smart, to find the evidence that corroborates their views. And Yelter says although we don't know about this bias question, there is something we

do know when it comes to IQ scores. And it's this. The world around you has a huge influence on how well you'll do. I mean, it's definitely so that the environment played a very important role. Studies have found that things like getting less education, living in a poorer neighborhood and being exposed to certain chemicals like lead and mercury can drop your IQ score. And in the US, on average, those things are more likely to affect you if you're black than if you're white. There's a great deal of differences between African-Americans and European-Americans.

It's not only schooling, it's also health. The nutrition that children get as they grow up is important. There's so many different things that can help explain the differences. A lot of the studies that find an IQ gap between white and black Americans, they haven't controlled properly for this stuff. It's very hard to control for institutional racism, which means we don't know why African-Americans perform lower on these tests. And when researchers do consider some of these factors, the IQ gap, it gets smaller. On top of this, no one has found a so-called intelligence gene

that pops up more in white people than in black people. In fact, there's been some new studies coming out on intelligence. And so far, all we can really say is that there are maybe a thousand genes or so, and each seem to have a tiny effect on intelligence. And we don't know if those genes are different in different populations. So basically, for those who are arguing that whites are the smarter ones and that this is genetic, Yelta is like, the science isn't there to back you up. We hardly know what's going on.

It doesn't make much sense to say that this was predetermined at birth. Given all that, it seems the only way we'll really know if one group is smarter than another is to control for everything in our environment. In other words, for example, make sure that black people in this country are treated as well and have the same opportunities as people who are white. So, when it comes to science versus race, does it stack up? One, can you see race in our genetics?

No, not in the way we think of as race. You can't neatly divvy people up into defined races based on their genetics. Still, though, you can see genetic differences in people depending on where their ancestors lived. Two, what do those differences mean? Often, the genetic quirks we see in populations popped up to help us survive in our environment, like places where the sun is strong

or where cow's milk is readily available. As for stuff like intelligence, well, we know that different groups of people, on average, do get different IQ scores. But there are just too many things that affect those scores to know what that means. So we don't have evidence that evolution pushed any group to be smarter than another. At the end of the day, though, much of this stuff about how humans did or didn't change thousands of years ago, it's practically impossible to know. And there are gaps in what genetics can tell us. So it feels like there are so many crevices that people can wiggle into to say, well, this is the proof that races exist.

I think the science tells us that it doesn't make sense to divide people by skin colour. For me, the one thing that Carl Linnaeus did get right about people, though, is that we really should be dividing up children into whether they were raised by wolves or not. So it's a shame that one didn't catch on. That's science versus race. Next week, we tackle the fertility cliff. If you wait too long to try to have a baby, are you screwed? It's much like buying eggs and putting in your refrigerator.

You can't just leave them there forever. Hello, hello, hello. Hello, hello, hello. Hi, Rose Rimla. Hey, Wendy Zuckerman. Of Science vs. Host of Science vs. How many citations in this week's episode? Hello, hello, hello. Hello, hello, hello. Hi, Rose Rimla. Hey, Wendy Zuckerman. Of Science Versus. Host of Science Versus.

How many citations in this week's episode? This week we have 123. 123. Are you impressed? I am impressed, although I saw them climbing throughout the week. So there they are. Do I get a prize? You get the prize of facts.

Yes. And knowledge. Yes. And knowledge. Yes. Where can people go if they want the prize of facts and knowledge? Their local library, of course. Well, if you want to see our transcript of all 123 citations, you can go to scienceverses.show and click on the episode, or it's also linked in our show notes, wherever you're listening right now.

Thanks, Rose. Thank you. This episode was produced by Rose Rimler with help from me, Wendy Zuckerman, as well as Meryl Horn and Michelle Dang. Our senior producer is Caitlin Sorey. We're edited by Blythe Terrell. Fact-checking by Michelle Harris, Meryl Horn and Michelle Dang. Mix and sound design by Peter Lennon. Music by Peter Lennon, Emma Munger and Bobby Lord.

Recording assistance from Bote Yelema and Shani Avaram. A huge thanks to Stillman Brown, Morgan Jerkins, Amber Davis, Cedric Shine, Emmanuel Jochi, and to all the scientists we got in touch with for this episode, including Professor Noah Rosenberg, Professor Rasmus Nielsen, Professor Mark Shriver, Dr. Garrett Hellenthal, Professor Sarah Tishkoff, Professor Kenneth Kidd, Finally, a huge thanks to the Zuckerman family and Joseph Lavelle Wilson. I'm Wendy Zuckerman. Back to you next time.