Hi I’m Wendy Zukerman and this is Science Vs from Gimlet. To start this episode we’re going back to the year 2000.
It’s a warm June morning in Washington DC and we’re in the White House’s East Room, where a press conference is set up. There’s an expectation in the air. Everybody stands. And in walks President Bill Clinton.
Clinton walks up to the podium and faces a room full of photographers, reporters, and scientists.
*here comes the chief*
Behind him, on a TV screen, is some sciency, but very cheesy imagery: a double helix and the words: Decoding the Book of Life.
BC 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.
BC Have revealed nearly 3 billion letters of our miraculous genetic code..
And on that stage one idea that was front and center was about race. Race had always been this concept that carried a ton of weight socially...but did it have any scientific meaning? Well now, the 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.
BC 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…
CV The concept of race has no genetic or scientific basis. There is no way to tell one ethnicity from another.
So these guys might have thought they were closing the door on the idea that race was biological… but actually this announcement left the race door ajar. Because 99.9% the same? ... That means 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...
You’re looking at someone in 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 that white people are the smarter, superior race.
OK, 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…
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 all about that, too. Science vs race is coming up right after the break.
BEAT 1: DOROTHY, LINNAEUS SHOWS THAT RACE WAS NEVER SCIENTIFIC
Welcome back. Today we’re talking about race, and asking scientifically: does it exist? And by that we mean… 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 the races is super complicated and messy... partly because it has this dodgy history…
To tell us all about it we got Professor Dorothy Roberts from the University of Pennsylvania into her office… and put a microphone in front of her…
DR Mmhmm I have a giant puffy thing in front of my mouth, fuzzy! it’s furry! It’s furry!
And pretty quickly, we got into the history of race and science. Dorothy told us it really began in the 17th and 18th Century in Europe.  It was the Age of Enlightenment… science in Europe was having a heyday… as scientists were racing to understand the world around them...
DR These typologists were classifying all of nature. They were classifying plants and animals and rocks and other aspects of the natural world, they included human beings.
Colonialism was in full swing... Europeans were sailing to Africa, the Americas and Asia -- seeing all these people who looked really different to themselves… And so they started to categorise them too. And this was a particular pastime of this highly respected botanist called Carl Linnaeus.
DR 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 and had some wild card categories too…. Like… there was this one called Juvenis lupinus [yoo-wen-is loo-PIE-nus] . Or, get this. Wolf boys, for children raised by wolves… really! Weirdly that one didn’t catch on. But what did catch on were some of the descriptions he and other scientists gave of each race - always giving Europeans the best adjectives.... Here’s Dorothy.
DR White people are characterized as the most beautiful and they’re also characterized as the most rational and black people are described as prone to violence, to laziness, to illness, to mental disorders.
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… White people at the top… And everyone else underneath them…
DR and all of those scientists thought they were being objective but we can now see in hindsight they were being woefully subjective. Ah 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 colonisation more generally … After all - if science says that Africans or Native Americans are.… a lesser group of people… then it’s OK to take their land, and enslave them.
DR 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 ...
DR Human beings regardless of race are more than 99.9% the same
So science had done a 180 since Carl Linneaus... and 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.
DR And so there’s no point denying, because it’s absolutely true that human beings are diverse genetically, yes you can see that. You can see that 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 … oops, wrong quote. When he told us that the Human Genome Project showed us that we’re 99.9 percent the same? Well what about that bit that’s left over?
DR The problem, though, is that the 0.1% is a lot of genetic variation.
Yeah, this is a lot. 0.1 percent amounts to around 10s 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 5 pound Chihuahua turns into a 50 pound Siberian Husky. So does the 0.1% leave the race door 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.
JG So I was 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, even when you zoom in on the 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’s complicated.
To sort it out, we first need a definition of biological race. We figure, for race to exist biologically, you would need to find … that people with the same appearance - like skin colour - should be a genetically uniform group. They should be really similar to each other. And they should be different from people with other skin colours. … So when just you 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 onto racial stereotypes, influencing different abilities and behaviors, 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, say have the same skin colour, 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 sampled from different portions of the spectrum of human being
Then scientists can put the DNA through an algorithm, and plug in how many categories they want us to file into…
if i want to see 5 clusters the algorithm will give me 5 clusters
One of those most influential studies that did this… looked at around 1000 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 darker 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.
JG If one for example, were to take Solomon Islanders they would look indistinguishable from sub-Saharan Africans
So that tells us … genetically speaking, if you want to put people into groups with their closest genetic relatives … skin color 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, the thing is, when you zoom in on that Africa cluster, you see a ton of diversity. Infact, it’s a genetic hotspot. Which makes sense, it’s where human beings came from in the first place.
JG One thing consistently agreed upon with regard to the history of our species is the origin of humans 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 colors, this idea of grouping us this way - and saying that all whites or black people are basically the same kind of people, doesn’t really make sense.
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 skin color is just a simple adaptation to the environment…. Not necessarily anything else…
JG SO if you're a sub-Saharan African you have darker skin. If you are in the Middle East and 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 yes people dark complected but that's about as far as that consistent difference goes.
Ok, so natural selection has worked its magic on us to make us LOOK DIFFERENT. What about traits that are invisible? Because we think for race to be biologically real, 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 or another. Do we see that? 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.
Colbert: And now most surprising of all, White supremacists have been chugging milk, because 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 East Africa and parts of the Middle East.  And that’s because cultures around the world have been domesticating cattle or thousands of years… long enough to evolve to chug a cold one.
And this is what you’d expect! humans are newbies on this planet, a relatively young species,...and we just haven’t had that much time to accumulate a ton of differences, the way other animals have. We’ve also never been THAT separate from each other. For thousands of years… people were having sex with their neighbors … or setting off in canoes and having babies in far flung places.
JG: And that’s what makes it impossible to define biologically race in our species because there isn’t enough variation at these regional and coninental regions to define groups that are different from each other. …
And so the way we throw around the word race...does it match what geneticists see when they look in our DNA?
JG No! That’s not correct.. So, that’s off the table… 
Evolution didn’t read Carl Linneaus’ book, and go, ok! Perfect! I’ll do that!
Still though... if we evolved to drink milk....and or have a different skin colour… could the environment have pushed some groups to evolve other - more complicated things, too? Like intelligence.
After the break, we tackle one of the most controversial claims, and one that’s been getting a lot of attention. And it’s that science actually shows that some groups are more intelligent than others … That’s 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 that makes sense…
JG That someone 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.
JG The thing your listeners probably don’t know is I was actually the first African-American to ever receive a Ph.D. in my field.
JG I went through professors sat in courses who 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 have 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 math  and agriculture.
But this question of… is one group more intelligent than another… is one we felt we HAD to look further into because it has 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. Folks like…Nobel Prize Winner James Watson…science writer Nicholas Wade...and podcaster Sam Harris… Here he is
SH 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? Ok… So… these people are saying this controversial things. And they say the proof that whites are smarter… lies in IQ tests… OK! These guys want to play in the science sandbox - let's see how they go. Science Vs Producer Rose Rimler and I called up an IQ expert…
JW My name is Jelte Wicherts
RR WZ Wicherts...wicherts…
JW VERY close
RR, WZ Wichert
JW Just add the S, and you’re in good place
Jelte is a professor of psychological methods at the University of Tilburg in the Netherlands. So we asked him…. Straight off ..
WZ When you compare blacks and whites who does better on IQ tests
JW Whites on average perform better
WZ How large is the difference?
JW So in IQ testing, the data appear to point to at least ten 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.
JW We do know that IQ scores predict an awful lot of things … JW We know 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 Jelte 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?
WZ Does this mean that white Americans are inherently smarter than black Americans…
JW No you can’t say that. There is a distinction between IQ scores and the thing we are trying to measure — namely, intelligence.
What Jelte means is that even though IQ Tests can tell us a lot about who’s going to be successful … they’re still 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 these tests are typically written by white people...who might have unintentionally included questions that are easier for white people to answer. This is actually what Jelte researches, so we asked him if it’s true… if the tests are biased.
And something that we’ve found frustrating is that we’ve seen people online cherry-picking the work of Jelte and others… pointing just to the findings that suggest these tests are fair and unbiased meaning, to them that… whites truly are smarter. So I asked him about it.
WZ: 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?
JW: I’m not aware of any of my papers that said that or show that in a particular way.
it just shows people have their opinions made up and then are very well equipped even if they’re smart to find evidence corroborates their views-01
And Jelte 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
JW 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 neighbourhood and being exposed to certain chemicals, like lead and mercury can drop your IQ score.  And in the U.S., on average, those things are more likely to affect you if you’re black than if you’re white.    
JW There’s a great deal of difference between African Americans and Europeans Americans . Not only schooling   , health  , the nutrition     children get as they grow up is important. There’s so many 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 or so genes that 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 … Jelte is like.. the science isn't there to back you up.
JW We hardly know what’s going on… It doesn’t make much sense to say this is predetermined at birth.
Given all that…it seems the only way we’ll know if one group is smarter than another … is to control for everything in the 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 Vs Race… does it stack up?
At the end of the day though, ... much of this stuff about how humans did or didn’t change thousands of years ago, is practically impossible to know. And there are gaps in what genetics can tell us. So it feels like there are so many crevices people can wiggle into to say THIS is proof that the races exist… I think - the science tells us 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 children up by whether they were raised by wolves or not. So it’s a shame that that one didn’t catch on.
That’s Science Vs Race.
Next week, we tackle the fertility cliff. If you wait too long to try to have a baby, are you screwed?
MS: it’s much like buying eggs and putting in your refrigerator. You can’t just leave them there forever.
This episode was produced by Rose Rimler, with help from me, 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 Professor Noah Rosenberg, Professor Rasmus Nielsen, Professor Mark Shriver, Dr Garrett Hellenthal, Professor Sarah Tishkoff, Professor Kenneth Kidd, Dr John Protzko, Dr Dan Levitis, and others.
Finally, thanks to the Zukerman Family and Joseph Lavelle Wilson.
I’m Wendy Zuk. Fact you next time.
 The East Room...June 26, 2000...10:19 A.M. EDT https://www.genome.gov/10001356/june-2000-white-house-event/
 On June 26, 2000, the International Human Genome Sequencing Consortium announced the production of a rough draft of the human genome sequence.
 Among the heightened expectations generated by the Human Genome Project (hereafter, HGP), scientists optimistically claimed that the project would provide definitive answers to enduring questions concerning the scientific status of ‘race’ as a biological category.
 DNA from five subjects was selected for genomic DNA sequencing: two males and three females—one African-American, one Asian-Chinese, one Hispanic-Mexican, and two Caucasians…...The decision of whose DNA to sequence was based on a complex mix of factors, including the goal of achieving diversity as well as technical issues such as the quality of the DNA libraries and availability of immortalized cell lines. https://science.sciencemag.org/content/291/5507/1304
 We have sequenced the genome of three females and two males, who have identified themselves has Hispanic, Asian, Caucasian or African American. We did this sampling not in an exclusionary way, but out of respect for the diversity that is America, and to help illustrate that the concept of race has no genetic or scientific basis. In the five Celera genomes, there is no way to tell one ethnicity from another. [Craig Venter speech]
 Current estimates of how much variation occurs species-wide indicates that all H. sapiens are ∼99.6–99.8% identical at the nucleotide sequence level. (This 2004 article reported 0.2-0.4% difference, but most current studies, including the NIH report 0.1%).
 any two humans differ, on average, at about 1 in 1,000 DNA base pairs (0.1%) https://www.ashg.org/education/pdf/geneticvariation.pdf
 the 0.1% of the human genome that consists of variable markers http://rosenberglab.stanford.edu/papers/Rosenberg2011-HumBiol.pdf
 From the NIH https://www.genome.gov/19016904/faq-about-genetic-and-genomic-science/ All human beings are 99.9 percent identical in their genetic makeup.
 1684 essay, French physician, pg 28 Fatal Invention
 Linnaeus’s “natural system,” which became the basis for the classification of all species, divided humanity into four groups: Americanus, Asiaticus, Africanus, and Europeaeus. To these groups he ascribed typological, or physical and behavioral characteristics. Americanus were “reddish, choleric, and erect; hair black… wide nostrils… obstinate, merry, content free… regulated by customs.” Asiaticus were “melancholy, stiff; hair black, dark eyes… severe, haughty, avaricious… ruled by opinions.” Africanus were “black, phlegmatic… hair black, frizzled… nose flat; lips tumid; women without shame, they lactate profusely; crafty, indolent, negligent… governed by caprice.” Finally, Europeaeus were “white, sanguine, muscular… eyes blue, gentle… inventive… governed by laws.” 9 Original 1758 10th ed. In Latin pg 20. (Though Linnaeus also authored ed. 12, his ed. 10 became the standard reference in the 1800s - determined by the Strickland Code of Zoological Nomenclature) . [1806 English Translation, pg 9]
 On page 20 , he lists categories of “HOMO” including “sepiens ferus, of which “juvenis lupinus heffenfis” is a category, along with sepiens Americanus, Asiaticus, Africanus, and Europeaeus. And page 9 here. For English translations, see here:
 Americans turned out to be “choleric,” Americans “reddish,” also “Americanus were “copper-colored, choleric, and erect; Hair black, straight, thick; nostrils wide, face harsh; beard scanty; obstinate, content free. Paints himself with fine red lines. Regulated by customs.””
 “the idea of emancipating the whole at once, the old as well as the young, and retaining them here, is of those only who have not the guide of either knowledge or experience of the subject. for, men, probably of any colour, but of this color we know, brought up from their infancy without necessity for thought or forecast, are by their habits rendered as incapable as children of taking care of themselves” https://founders.archives.gov/documents/Jefferson/03-07-02-0439 and here https://www.jstor.org/stable/2645866
 http://sci-hub.tw/10.1525/napa.1918.104.22.168 Before World War II, with a few exceptions, anthropologists in the United States and abroad not only accepted but also provided the scientific support for the traditional race categories. Like nearly all of their contemporaries, Hooton, Keith, and Hrdlicka presented human races as real, natural, and unquestioned varieties.
 1951 UNESCO statement, see bullet points starting pg 11: https://unesdoc.unesco.org/ark:/48223/pf0000073351
 Opinion piece from 1996: This division of Homo sapiens into race taxons started in the 18th century, when the sciences of genetics and evolutionary biology were not yet invented. These disciplines have since shown that human race taxonomy has no scientific basis. Race categories are social constructs, that is, concepts created from prevailing social perceptions without scientific evidence. https://annals.org/aim/article-abstract/710064/medicalization-race-scientific-legitimization-flawed-social-construct
 When published in 1981, The Mismeasure of Man was immediately hailed as a masterwork, the ringing answer to those who would classify people, rank them according to their supposed genetic gifts and limits. https://www.amazon.com/dp/B007Q6XN2S/ref=dp-kindle-redirect?_encoding=UTF8&btkr=1
 This booklet reproduces the texts of four statements is the race issue Prepared by groups of experts brought together by UNESCO in 1950, 1951, 1964 and 1967 as share of its program to make known the scientific facts about race and to fight racial prejudice. Conference of experts meeting in Paris in September 1967, agreed that racist doctrines lack any scientific basis whatsoever. ….. The division of the human species into 'races' is partly conventional and partly arbitrary and does not imply any hierarchy whatsoever. Many anthropologists stress the importance of human variation, but believe that 'racial' divisions have limited scientific interest and may even carry the risk of inviting abusive generalization. (c) Current biological knowledge does not permit us to impute cultural achievements to differences in genetic potential. [18 people signed] https://unesdoc.unesco.org/ark:/48223/pf0000122962
 See citations 11-13
 From 2016: https://sci-hub.se/10.1038/nature18964 We developed a filtering procedure that generates a sample-specific mask. At ‘filter level 1’ which we recommend for most analyses, we retain an average
of 2.13Gb of sequence per sample and identify 34.4 million single nucleotide polymorphisms (SNPs) and 2.1 million insertion/deletion polymorphisms (indels) (Supplementary Information section 2).
 https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4750478/ We characterized a broad spectrum of genetic variation, in total over 88 million variants (84.7 million single nucleotide polymorphisms (SNPs), 3.6 million short insertions/deletions (indels), and 60,000 structural variants), all phased onto high-quality haplotypes.
 And from the current national database https://ghr.nlm.nih.gov/primer/genomicresearch/snp These variations may be unique or occur in many individuals; scientists have found more than 100 million SNPs in populations around the world
 Eighty-five to ninety percent of neutral genetic variation in the human species is due to differences between individuals within populations (Lewontin 1972; Barbujani et al. 1997; Jorde et al. 2000). The remaining 10%–15% is distributed between groups, and, though modest, this variation influences the average differences in physical characteristics, disease susceptibility, and treatment outcome among populations
 we show that a single IGF1 allele is a major determinant of small size in dogs and that intense artificial selection has left a signature in the proximity of IGF1 that can readily be found by genomic scans of breeds sharing a common phenotype https://pdfs.semanticscholar.org/b164/f0a27d2a9299592c522b9f322b1c37336240.pdf
 Fear measured on Figure 1 B) and also “Overall, we identified 131 unique SNPs that were significantly associated with at least one of the 14 behavioral traits (Bonferroni p ≤ 0.05, Fig 2). Forty percent of these SNPs (n= 52) were located within a gene”
 Cited >500 times
 A total of 367,220 runs of STRUCTURE were performed on subsets of a dataset consisting of 1,048 individuals from the Human Genome Diversity Project–Centre d’Etude du Polymorphisme Humain (HGDP-CEPH) Human Genome Diversity Panel  and 993 microsatellite and insertion/deletion polymorphisms. https://rosenberglab.stanford.edu/papers/clinesclusters.pdf
 https://rosenberglab.stanford.edu/papers/clinesclusters.pdf see Fig 2: the colors represent the “individual’s estimated membership fractions”, and they let the program split the data up into 2-6 colors. Europeans form this blue group, which also makes up a large proportion of middle easterners and central/south asians.
 African group (orange) vs. Melanesian (part of oceania) group (green or pink depending on cluster number), who also have dark skin, https://rosenberglab.stanford.edu/papers/clinesclusters.pdf
 Today, indigenous people of the South Pacific harbour a mixture of ancestry from Papuans and a population of East Asian origin that no longer exists in unmixed form, but is a match to the ancient individuals. https://www.nature.com/articles/nature19844
 Email from Skoglund to RR 3/19: Yes that is correct. Solomon Islanders are closely related to both East Asian peoples, and secondarily to aboriginal Papuan peoples.
 In terms of nucleotide substitutions, the Bushmen seem to be, on average, more different from each other than, for example, a European and an Asian. 0https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3890430/
 Modern humans originated in Africa ~200,000 years ago and then spread across the rest of the globe within the past ~100,000 years (1). Thus, modern humans have existed continuously in Africa longer than in any other geographic region and have maintained relatively large effective population sizes, resulting in high levels of within-population genetic diversity. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2947357/
 Dramatic claims about divergent selection should continue to be regarded cautiously in the absence of strong quantitative evidence...It might be proposed that different strengths of directional selection have contributed to the population difference between African Americans and European Americans. However, a related computation of the overall influence of natural selection in human history, relying on measures of selection against deleterious variants rather than directional selection of favorable variants, does not suggest strong systematic differences in the magnitude of selection among different continental population groups [50– 52]; indeed, some researchers have argued for a greater level of deleterious variation in non-Africans rather than in Africans [50, 52], a pattern opposite to what might be expected given the direction of health disparities. Whereas natural selection cannot easily explain the observed population difference, systematic environmental effects that contribute to an increase in non-genetic risk factors in African Americans—current and historical racism, for instance [53– 55]—could, on the other hand, explain such marked differences. http://rosenberglab.stanford.edu/papers/RosenbergEtAl2019-EMPH.pdf
 The earliest members of the hominid lineage probably had a mostly unpigmented or lightly pigmented integument covered with dark black hair, similar to that of the modern chimpanzee. The evolution of a naked, darkly pigmented integument occurred early in the evolution of the genus Homo. https://www.sciencedirect.com/science/article/pii/S0047248400904032
 Skin pigmentation is probably one of the best examples of natural selection acting on a human trait. It is the product of two opposing clines, one emphasizing dark constitutive pigmentation and photoprotection against high loads of UVA and UVB near the equator (Figs. 1 and 2), and the other favoring light constitutive pigmentation to promote seasonal, UVB-induced photosynthesis of vitamin D3 near the poles (7, 49). http://sci-hub.tw/https://doi.org/10.1073/pnas.0914628107
 In conclusion, multiple independent variants have allowed various human populations to quickly modify LCT expression and have been strongly adaptive in adult milk-consuming populations, emphasizing the importance of regulatory mutations in recent human evolution https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2672153/?_escaped_fragment_=po=11.6667
 The LDC [ high lactose digestion capacity] of over 20,000 individuals worldwide has been tested. High frequencies (>70%) of adults with high LDC are found in northern Europeans and their descendants in North America and Australia and among some African pastoralist groups thought to have originated in North or East Africa. Intermediate frequencies (30–70%) of adults with high LDC are found around the Mediterranean, the Middle East, and in central and south Asia. Regions whose adult populations predominantly have low LDC include much of sub- Saharan Africa, east and southeast Asia, and the native populations of the Americas and Oceania.
 The frequency of lactase persistence is high in northern European populations (>90% in Swedes and Danes), decreases in frequency across southern Europe and the Middle East (~50% in Spanish, French and pastoralist Arab populations) and is low in non-pastoralist Asian and African populations (~1% in Chinese, ~5%-20% in West African agriculturalists)1-3. Notably, lactase persistence is common in pastoralist populations from Africa (~90% in Tutsi, ~50% in Fulani)1,3. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2672153/?_escaped_fragment_=po=11.6667
 https://journals.plos.org/plosbiology/article?id=10.1371/journal.pbio.0040072 Though most selected regions are not shared across populations, there is still a clear excess of shared selective events. Indeed, since we have incomplete power to detect selection, it is likely that we tend to underestimate the degree of sharing across populations.
 From its origins in sub-Saharan Africa, the Arabian peninsula and the Indian subcontinent, population migration has increased SCD prevalence in areas not previously associated with the disorder, such as the USA, western and northern Europe. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5094105/
 https://www.who.int/bulletin/volumes/86/6/06-036673-table-T1.html Table of world prevalance, see Sickle-cell disorder column
 (one example) “It has been estimated that the tiger evolved about 2.2 million years ago (MYA) based on a cladistical analysis , although molecular data from Johnson and colleagues in 2006 suggest a divergence of the tiger from other Panthera about 2.9–3.7 million years ago .” There exist confirmed subspecies of tiger.
A variety of dispersal models (Table 1) address the period between the widely accepted African origin of Homo sapiens by around 200-150 ka and the arrival of our species at the margins of the Old World, including Australia, Siberia, and northwest Europe, by 50-40 ka.1–4
 The combination of these results shows that among the alleles considered, none are present in all members of one region but absent from individuals outside the region. While occasional alleles with large frequency differences do exist, they are unusual, and they do not typically approach the maximal possible level of divergence. As a fraction of all alleles, strongly diverged alleles are rare. http://rosenberglab.stanford.edu/papers/Rosenberg2011-HumBiol.pdf
 Jim Patton: “...Carleton Coon (a well respected anthropologist at the University of Pennsylvania) published his book "The origin of races" in 1962, which documented the how and why of human racial diversity. Scholars, however, stopped using taxonomic racial divisions for humans shortly thereafter -- primarily because segregationists began to use Coon's divisions as a basis for their view of the world, and with the then burgeoning study of genetic variation that showed how massively human populations over time had dispersed and interbred (for example, work by Luca Cavali-Sforza, a human geneticist then at Stanford, or biostatistician Robert Sokal who mapped the patterns of admixture among the previously viewed taxonomic races across great Europe). Any good physical anthropologist can "assign" a set of skulls to a regional group of humans based on quantitative and qualitative morphological differences, but assigning race (=subspecies) to these groups became such a socio-political fraught issue that human races are no longer recognized in the scientific literature.”
 To date, strong effects of directional selection on human population differences have been verifiable primarily for traits connected to predictable categories of geographic variability, including dietary adaptations, infectious disease resistance and skin pigmentation [14–16]. http://rosenberglab.stanford.edu/papers/RosenbergEtAl2019-EMPH.pdf
 Cognitive demands placed by the need to survive harsh winters in cold climate select for higher intelligence, and thus general intelligence is expected to evolve and become higher in colder climates
The more evolutionarily novel the environment, the higher the average intelligence
 Infectious diseases https://royalsocietypublishing.org/doi/pdf/10.1098/rspb.2010.0973
 https://books.google.com/books?hl=en&lr=&id=bR9HAAAAQBAJ&oi=fnd&pg=PP16&dq=invention+of+math++Babylonians+and+Egyptians+&ots=AvSGxynXCY&sig=3jWkSvBgaTuRoYdtuBk0EMhdVSg#v=onepage&q=%22when%20it%20came%20to%20mathematics%2C%20he%20held%22&f=false roots of geometry in Egypt
 http://sci-hub.tw/10.1007/s10649-006-9023-7 . “It would seem that the earliest algebra – ideas which relate to the eighteenth century definitions by Euler and Maclaurin – comes from Mesopotamia starting about 4000 years ago…The first true algebra text which is still extant is the work on al-jabr and al-muqabala by Mohammad ibn Musa al-Khwarizmi, written in Baghdad around 825 (Al-Khwarizmi, 1831).”
 https://science.sciencemag.org/content/282/5393/1446 The latest evidence suggests, for example, that hunter-gatherers in the Near East first cultivated rye fields as early as 13,000 years ago.
 https://www.nytimes.com/2014/07/13/books/review/a-troublesome-inheritance-and-inheritance.html?module=inline https://www.nytimes.com/2014/08/10/books/review/letters-a-troublesome-inheritance.html
 For several decades in the United States, the mean IQ of the African-American population had been averaging about one standard IQ deviation below the average for the Euro-American population (Herrnstein & Murray, 1994). Recent analyses of standardization samples suggest that this gap had decreased five to six points from 1972 to 2002 (Dickens & Flynn, 2006). On the other hand, Rushton and Jensen (2006) have rebutted this claim and Murray (2006) has argued that the IQ gap between these populations has remained stable. https://openpsych.net/forum/attachment.php?aid=473
 Averaging over the six indices of gap reduction, we get an IQ gain equivalent of 6.45 points—somewhat higher than the 5.5-point gain for IQ found by Dickens and Flynn (2006) for the period 1972–2002. http://sci-hub.tw/10.1037/a0029772
 all results from these other studies are compatible with our estimate of an IQ of 90.5 for Black schoolchildren in 2002.( if White IQ at all ages is set at 100 , difference is 9.5) http://sci-hub.tw/10.1111/j.1467-9280.2006.01802.x y. ...The constancy of the Black-White IQ gap is a myth and therefore cannot be cited as evidence that the racial IQ gap is genetic in origin. Blacks have gained 4 to 7 IQ points on Whites over the past 30 years
 It would take us far afield to discuss why the gains occurred when they did, but the main relevance is that the old estimate of 1 standard deviation in ability scores no longer applies. The gap is substantially less than that at the present time, probably more like 0.6–0.7 standard deviation or approximately 10 IQ points. https://www1.udel.edu/educ/gottfredson/30years/Nisbett-commentary-on-30years.pdf
Another study that showed IQ stability over time: https://www.sciencedirect.com/science/article/pii/S104160801400020X
 https://journals.sagepub.com/doi/abs/10.1177/0956797618774253 Intelligence test scores and educational duration are positively correlated.
areas concerning the personological significance of cognitive abilities and the methods used to study
 source: IQ measures general intelligence and a host of lower order factors and cognitive abilities that are specific to any given subtest. Seeing an overall gap in IQ (just an average across all the subtests in the IQ battery) does not mean that the difference can be attributed only to general intelligence or g, as the gap can also be due to lower order factors (e.g., crystallised abilities, working memory, spatial abilities etc) and even to very narrow abilities that have little bearing on g itself (e.g., I can train my mental rotation ability very narrowly but that does not imply that my g goes up), and measurement bias.
 http://sci-hub.tw/10.1037/1076-8922.214.171.124 This explanation is now known as the cultural test bias hypothesis, and stated simply, says that group differences in mental test scores occur due to systematic underestimation of minority groups' aptitude levels; or, more generally, tests contain systematic error that occurs as a function of what should be irrelevant nominal group membership (e.g., race, ethnicity, gender, and socioeconomic status).
 The potential for tests to be biased has long been recognized, with methods of administration, content and test conditions all being potential sources of discrepancies in both the size and explanation of the gap (Burchinal & Cryer, 2003; Helms, 1992; Jencks, 1998; Rock & Stenner, 2005; Suzuki & Valencia, 1997).
 Biased: More importantly, in both B–W studies, it is concluded that the measurement invariance between Blacks and Whites is tenable because the lowest AIC values are found with the factorial invariance models (Dolan, 2000; Dolan & Hamaker, 2001). This clearly contrasts with our current findings on the Flynn effect... IQ gaps between cohorts do not teach us anything about IQ gaps between contemporary groups, except that each IQ gap should not be confused with real (i.e., latent) differences in intelligence.
 Unclear: Dolan & Hamaker, 2001: https://psycnet.apa.org/record/2002-01002-002 The results of the MGCFAs suggest that it is very difficult to distinguish between competing hypotheses concerning the latent sources of B-W differences.
 Unbiased: Dolan, 2000: http://sci-hub.tw/https://www.ncbi.nlm.nih.gov/pubmed/26777230 “The finding that factorial invariance is tenable suggests that the tests are unbiased with respect to group”.
 http://sci-hub.tw/10.1111/j.1745-3992.2010.00182.x looks at bias between Moroccan and Turkish immigrants vs Dutch children “By not testing for intercept differences, Te Nijenhuis et al.
(2004) overlooked the fact that at least three of the twelve subtests in the RAKIT are biased against 7-year-olds of Moroccan and Turkish descent”
 Review, concludes mostly unbiased https://onlinelibrary.wiley.com/doi/pdf/10.1002/9781118133880.hop210004 Test bias exists but is small, which raises questions about its importance. It most often overestimates or over predicts minority examinees’ performance, so that its social consequences may be very different from those typically ascribed to it, and appropriate responses to it may differ from those typically made.
 We found consistent evidence for beneficial effects of education on cognitive abilities of approximately 1 to 5 IQ points for an additional year of education https://journals.sagepub.com/doi/abs/10.1177/0956797618774253
 Lead and mercury http://pm.amegroups.com/article/view/4617/html The best fitting model indicated that an increase in concurrent blood lead concentration from 2.4 to 30 µg/dL (the 5th and 95th percentiles of the blood lead distribution in the pooled dataset) was associated with an IQ reduction of 6.9 points….. Each increase of 1 µg/g (part per million) in maternal hair-mercury was associated with a loss of one-half IQ point (10).
 Neighborhood poverty http://sci-hub.tw/10.1086/230268 There are reasonably powerful neighborhood effects-particularly the effects of the presence of affluent neighbors-on childhood IQ, teenage births, and school-leaving, even after the differences in the socioeconomic characteristics of families are adjusted for.
 https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5127296/ Blacks in particular are significantly more likely than other Americans to live in high-poverty neighborhoods
 https://www.ncbi.nlm.nih.gov/pubmed/28886415 African-American children (N=71) had 2.2 times higher lead levels in the second and third trimesters (both p<0.001) and 1.9 times higher lead levels postnatally in the first year of life (p=0.003) compared to white children (N=51)
 https://ajph.aphapublications.org/doi/pdf/10.2105/AJPH.86.10.1460 The geometric mean blood lead level for Black children was significantly higher than that for White children: 8.8 p.g/dL vs 4.7 ,ug/dL, respectively (P < .001).
 https://ehp.niehs.nih.gov/doi/pdf/10.1289/ehp.98106745 Sociodemographic factors associated with higher blood lead levels in children were non-Hispanic black race/ethnicity, low income, and residence in older housing.
 https://jamanetwork.com/journals/jama/fullarticle/196298 mercury- also higher levels in non-Hispanic black women and childrenous “ Geometric mean total mercury levels in non-Hispanic black and Mexican American children were higher than in non-Hispanic white children; the differences were small but statistically significant (Table 1).... Among women aged 16 to 49 years, non-Hispanic blacks had higher geometric mean mercury levels compared with non-Hispanic whites and Mexican Americans (Table 2).
 http://sci-hub.tw/10.1177/0042085907312315 Education Trust– West (2005) found a gap of an average $472,152 per year between high- and low-minority high schools in California. This translates to a mean difference of $573 per student in California, and, in New York and Illinois, the differential between high- and low-minority high schools was $2,615 and $2,465 per student, respectively
 http://sci-hub.tw/10.3102/0013189X035007003 The Chicago public schools spend about $8,482 annually per pupil, while nearby Highland Park spends $17,291 per pupil. The Chicago public schools have an 87% Black and Latina/o population, while Highland Park has a 90% White population…. (more examples in article).
 Certain disparities were particularly marked for specific racial/ethnic groups: for Latinos, suboptimal health status and teeth condition, uninsurance, and problems getting specialty care; for African Americans, asthma, behavior problems, skin allergies, speech problems, and unmet prescription needs http://sci-hub.tw/10.1542/peds.2007-1243
 . Hispanics fared worse than blacks in both health status and insurance coverage, and blacks fared worse than whites. http://sci-hub.tw/https://ncbi.nlm.nih.gov/pmc/articles/PMC2568689
 the proportions with a usual source of care were as follows: whites, 90%; Native Americans, 61%; Latinos, 68%; African Americans, 77%; and Asians or Pacific Islanders, 87%
 After adjustment, the ‘processed’ (high fat and sugar content) pattern of diet at 3 years of age was negatively associated with IQ assessed at 8.5 years of age—a 1 SD increase in dietary pattern score was associated with a 1.67 point decrease in IQ (95% CI −2.34 to −1.00; p<0.0001). The ‘health-conscious’ (salad, rice, pasta, fish, fruit) pattern at 8.5 years was positively associated with IQ: a 1 SD increase in pattern score led to a 1.20 point increase in IQ (95% CI 0.52 to 1.88; p=0.001). https://jech.bmj.com/content/66/7/624.short
 prolonged malnutrition during childhood does have long-term intellectual effects. These have not been easy to establish, in part because many other unfavorable socioeconomic conditions are often associated with chronic malnutrition … Although the degree of malnutrition prevalent in these villages rarely occurs in the United States, there may still be nutritional influences on intelligence. In studies of so-called "micro-nutrients," experimental groups of children have been given vitamin/mineral supplements while controls got placebos. In many of these studies (e.g., Schoenthaler, Amos, Eysenck, Peritz, & Yudkin, 1991), the experimental children showed testscore gains that significantly exceeded the controls. http://sci-hub.tw/10.1037/0003-066X.51.2.77
 (2016) Children living in higher-poverty neighborhoods are more likely to experience food insecurity than those in lower-poverty neighborhoods. … There was considerable racial and ethnic segregation by neighborhood poverty level. High-poverty neighborhoods averaged higher proportions of Black and Hispanic children and fewer White children than lower-poverty neighborhoods: 84% of children in tracts with 40% or greater poverty were Black or Hispanic, compared to 20% in tracts with less than 14% poverty. http://sci-hub.tw/https://doi.org/10.1016/j.childyouth.2016.05.006
 (1996) Children from underserved ethnically diverse population groups were at increased risk for obesity, increased serum lipid levels, and dietary consumption patterns that do not meet the Dietary Guidelines for Americans. http://sci-hub.tw/10.1016/S0002-8223(96)00242-8
 While this review paper cites studies controlling for “socioeconomic status” the papers cited use proxies which don’t include families income or quality of education. e.g. this paper describes their process, matching children on “age, sex, geographic region, father's occupation, and urban-rural residence” and then occasionally using parental education, noting they don’t have salary information. This paper says “socioeconomic status as determined by the occupation of the head of household, region of residence in the U.S. and urban vs rural residence.”, page 43 here says “Determination was also made of each child’s socioeconomic status (SES) on Duncan’s SES index, a ten-point scale based on the parent’s occupation.” This way of controlling for SES (based primarily on father’s occupation) has been critiqued here, here, and here . According to this, “ Usually, a measure of SES has three major components: (a) family income, (b) parental education, and (c) parental occupation.”
 In fact, controlling for SES only reduces the mean Black–White group difference in IQ by about a third, around 5 IQ points. The genetic perspective does not regard this control for SES as being entirely environmental. https://www1.udel.edu/educ/gottfredson/30years/Rushton-Jensen30years.pdf [this paper doesn’t include citations for this statement. Jensen (one of the authors) has published on this in his book, which says page 43: average IQ difference between races independent of SES is 12, while on page 44 “the overall IQ difference between whites and blacks in 15 points., so drops by 3 points.- MH]
 https://onlinelibrary.wiley.com/doi/pdf/10.1002/9781118133880.hop210004 Researchers have taken into account a number of demographic variables, most notably SES. The size of the mean Black–White difference in the United States then diminishes to .5 to .7 SDs (Jensen, 1980; Kaufman, 1973; Kaufman & Kaufman, 1973; Reynolds & Gutkin, 1981) but is robust in its appearance. (down from 1 SD without controlling for these )
 Reynolds & Gutkin 1981 http://sci-hub.tw/10.1016/0191-8869(81)90021-0 “The differences quite consistently ranged from 0.5-.7 standard deviations”… . “When SES in particular has not been controlled, the differences typically approach a full standard deviation.” ... SES determined by “father’s occupational status”
 There is the potential, therefore, for genetic factors to contribute to phenotypic differences between groups. But the skepticism of some scientists of the early 1970s regarding our ability to find genes (if such genes exist) underlying group differences in behavioral traits such as intelligence seems warranted. We are far from characterizing the contribution of genes to between-group variation of any complex trait and are likely to continue struggling in the future. https://www.nature.com/articles/ng1456
 http://sci-hub.tw/https://www.nature.com/articles/s41588-018-0152-6 Here, we present a large-scale
genetic association study of intelligence (n= 269,867), identifying 205 associated genomic loci (190 new) and 1,016 genes (939 new)
 https://journals.plos.org/plosbiology/article?id=10.1371/journal.pbio.0040072#pbio-0040072-b008 the types of genes that’ve been under positive selection recently govern things like olfaction and fertility, the authors don’t mention intelligence