miércoles, 1 de abril de 2015

Race, Inheritance, and IQ

Please note that my page HBD Fundamentals contains the references to the supporting pieces of research. I’ve linked to the relevant sections of the page and other references in each section below. What follows is a concise introductory counter to each point.

Index of claims:

1. Only White Supremacists, neo-Nazis, the KKK, etc. believe in a biological basis to racial differences in behavior and intelligence.
2. Race is a social construct and doesn’t exist.
3. Human genetic variation is clinial (i.e., smooth), hence you can’t separate humanity into distinct races
4. There can’ t be races or racial differences because everyone knows serious human evolution stopped 50,000 years ago.
5. The primary cause of differences in human behavioral traits and intelligence is our environmental circumstances, not our genes.
6. Intelligence and behavioral traits can’t be in any way inherited, because no one has found a “gene for intelligence” or for any behavioral trait.
7. Nobody knows what intelligence is, or how to measure it, and it is certainly not measured by IQ tests.
8. Non-Whites score low on IQ tests because the tests are culturally biased.
9. Poverty and/or discrimination are the causes of racial gaps intelligence.
10. Charles Murray, Nicholas Wade, Richard Lynn, Steve Sailer, and all these other “race” scientists think all Black people are dumb and are criminals.
11. For more.

1. Only White Supremacists, neo-Nazis, the KKK, etc. believe in a biological basis to racial differences in behavior and intelligence.
Wrong. In fact, some of us who believe in these biologically-based differences are people of color (and even have children of color)

(Oh, if any of you doubt that that’s my hand, ask Audacious EpigoneJohn Durant, or Zhana Vrangalova). In the case of my wife, she is a White liberal feminist Yankee from Maine, and she believes that biology is involved in human differences.
2. Race is a social construct and doesn’t exist.
Well, yes, race IS a social construct. But race does exist. Saying something is a “social construct” can be true and still yet not be really meaningful.
Think of it, the periodic table of chemical elements is a social construct. Do chemical elements then not exist? Or, much more relevant – in fact, exactly like race – Linnaean taxonomy is a social construct. Do kingdoms, classes, species not exist? Race is merely an extension of this.
In reality, genetic analysis can separate human populations into distinct groups. This works at the level of continental groups or even ethnic groups within a continent (or even groups within an ethnicity). At times the progression is smooth, with each group gradually giving way to the next, and at other times, the transition is abrupt.
                                          A map of the genetic distance of human populations   


                                                                                (source)


Even within continents – within countries even – you can see a pattern genetically (from here andhere, respectively):


Human populations can be likened to piles of sand of various colors. Imagine these colored piles spread out on a surface:

Each individual can be thought of as a single grain. Each of the grains are slightly different (indeed, no two grains are exactly alike), but there are broad similarities among certain sets of grains. You can clearly pick out the colored lumps. But it can be hard to pick out exactly where one pile ends and another begins. Indeed, individuals like myself, with West African, European, East (and likely South) Asian ancestry make any classification system demanding crisp and absolute delineation difficult, if not impossible.
Because people have historically mated with people nearby, this relative isolation has allowed random genetic changes (genetic drift) and effects of the different selective pressures (evolution) to leave a wonderfully varied pattern in the human genetic code, and, by extension, in humans.

3. Human genetic variation is clinial (i.e., smooth), hence you can’t separate humanity into distinct races.

Related to the above, for those that accept that genetic analysis can indeed separate humanity into distinct populations, they then claim that “race” doesn’t exist because human variation is “clinial”, that is, continuous. Across continents, neighboring groups don’t separate into sharply distinct races but slowly give way to from one group to the next, so they claim. Because of this, the claim is that different racial groups don’t exist.
Indeed, you do often see a smooth progression of human groups as you travel across continents:


…as these collages of facial composites of different peoples across the world (from The Postnational Monitor) show (the groups in the collages aren’t arranged in geographic order, but the point should still be evident). So is this true? Because the distribution of population-wide differences are often so smooth, do races then not exist?
Answer: how fucking dumb is that? Firstly to say that a “smooth” clinial progression of human differences renders the individual groups non-existent is equivalent to looking at this:

…and concluding that each individual color does not exist because they smoothly blend into one another. That’s clearly patently ridiculous. Even if the distribution of human groups is continuous (and it often is), that wouldn’t render each group along the distribution non-existent – nor would it render the differences between each group insignificant. That would be tantamount to saying yellow is equivalent to orange.
Second, the claim that the distribution of human populations is always clinial is not even trueRazib Khan once addressed this:

In the recent ‘do human races’ exist controversy Nick Matzke’s post Continuous geographic structure is real, “discrete races” aren’t has become something of a touchstone (perhaps a post like Cosma Shalizi’s on I.Q. and heritability).* In the post Matzke emphasized the idea of clines, roughly a continuous gradient of genetic change over space. Fair enough. But in the map above I traced two linear transects. I would suggest that anyone who has a general understanding of the demographics of South-Central Eurasia would immediately anticipate that these transects would reveal a relatively sharp break in allele frequencies. True, there are intermediate populations between the two end points, in Nepal, and on the fringes of India’s northeastern states. But clearly about halfway through the southwest-northeast transect you’ll see a rapid shift in allele frequencies. The blue transect is different, insofar as the change occurs very near its eastern pole. In Bengal, 85% of the length of the transect from its western terminus, the populations will still be far closer genetically to those on the western pole than those just to the east!
Indeed, the stress on the “clinial” nature of human population and genetic distribution is actuallymotivated obfuscation, as is much of the discussion on inherited human differences (which this page was written to address).
For more, please see these by Razib Khan:
And this by Greg Cochran:
4. There can’t be races or racial differences because everyone knows serious human evolution stopped 50,000 years ago.
Not true. In reality, human evolution has accelerated during that time (see Hawks, Wang, Cochran, Harpending, and Moyzis, 2007), especially during the last 10,000 years since the advent of agriculture. A simple look at the distribution of lactose intolerance is enough to disprove the idea that significant human evolution stopped in the distant past:

Physicist Gregory Cochran’s and anthropologist Henry Harpending’s 2009 book The 10,000 Year Explosion: How Civilization Accelerated Human Evolution details this. The advent of agriculture and the rise of states both greatly enhanced the rate of human evolution. Cochran has a blog post where gives a neat little illustration of this process:
In short, agriculture led to greatly increased population size. Increased population meant more individuals in which mutations could appear. More mutations meant that natural selection had more to work with.
Indeed, this age estimate of several human alleles (genetic variants) from Hawks et al. graphically demonstrates this process:

Many genetic variants aren’t all that old, many only appearing in the last 20,000-10,000 years.
The rise of states and the more and varied environments humans created for themselves meant stronger and more geographically and temporally variable selective pressures. This all served quicken the pace of human change and biodiversification.
5. The primary cause of differences in human behavioral traits and intelligence is our environmental circumstances, not our genes.
Absolutely untrue. In fact, recent evidence has been showing us just how wrong this really is. I could tell you something to the effect that it’s “nature AND nurture” and “everyone knows that it is 50-50 genes and environment”, but these are really obfuscatory oversimplifications rather than purveyors of real knowledge. First of all, of course, overall environment is important to one’s life outcomes – try living life alone on a deserted island and see. Yes, humans require certain basic environmental inputs to function and develop (most basic being food, air, water, etc.). But when people talk of this, the thing that they’re interested in is what degree the differences between people – differences which include:
  • Differences between individuals within a group
  • Differences in the same group at different times
  • Differences between different groups
…are caused by differences in each’s respective environment? Well, we can give answers to each. In the case of differences between individuals within a group, we can exactly quantify the extent that genes are involved, at least on a statistical level. In the case of differences in the same group at different times, the answer depends on the length of time under consideration and the degree of difference in question. For big changes that occurred over a short period of time (for example, the rise in obesity rates or the decline in marriage rates), we can say that environmental differences between those times are almost entirely responsible (even if we can’t necessarily tell which environmental differences mattered or how they did so) – even though within a time period, genetic differences are heavily involved in the differences we see. For smaller magnitude differences over time, or differences over very long periods of time (like hundreds of years), such as, for example, the decline in violence in Europe (from here and here):

…genetic change, either through demographic change or genetic change within a population (i.e., evolution) can and likely does have a role to play in the changes we see.
For differences between groups, these can be caused by either genetic differences and environmental differences, and indeed, both play some role. But to understand these, let me return to differences between individuals within a group. As I said, we can precisely quantify the contribution of genes to these differences. This is through the magic of behavioral genetics. Behavioral genetics is a technique to separate the genetic from the “non-genetic” component to variance among individuals. The common way to do this is with twins. You can compare identical twins with fraternal twins, for one. But you can also look at twins raised apart; at adopted children; at half-siblings vs. full-siblings; at various members of extended family, etc. Newer methods can now directly measure genetic similarity among individuals and compare this to the trait or outcome of interest. All of these methods produce about the same results, roughly captured by this chart of the heritability of IQ throughout life:

As this shows, the heritability of IQ and of behavioral traits is consistently high, reaching into the 0.8-0.9+ range. This means, out of a group of people, at least 80-90% of the overall differences between them (known as the “variance” in statistical parlance) can be attributed to genetic differences between them. This chart shows that this becomes most evident in adulthood, when genes have been given a chance to fully express themselves. I have summed this up in a neat set of rules:

About the “shared environment”: this is the similarity between children growing up together less the effect of genetics (captured in the similarity between adoptive siblings, for example). The impact of this component is consistently 0. Adoptive siblings might as well be random strangers for the degree of similarity between them in intelligence, behavioral traits, or outcomes. This represents the any potential effects of parenting and upbringing. This research tells us that there aren’t any such lasting effects. That is, our intelligence, behavioral traits, or adult outcomes have nothing to do with parental treatment.

So this brings me back to differences between groups. We know differences between individuals in a group are heavily due to genetics. But what about differences between groups? The incredibly high heritability of behavioral traits and the reality of group-wide genetic differences would suggest that differences between groups must also involve genetics. We also know that “environment” doesn’t seem to be hugely significant in generating differences between individuals in a group. (There is some left-over variance, termed the “unique” or “non-shared” environment in behavioral genetic studies, but the origin of this is unknown. Evidence indicates that much of this may be the effects the prenatal environment, or in fact ultimately genetic – undetectable in twin studies thanks to the subtle genetic differences between identical twins), But, in principle, the “environmental” causes of differences within a group may differ between those that cause differences between groups. However, in reality, there has been little success in establishing firm environmental sources of between-group differences. It can be safely said that the genetic & “environmental” architecture of the differences between groups resembles that of the differences between individuals in a group. We will see more about this below where I talk about racial differences in IQ.

6. Intelligence and behavioral traits can’t be in any way inherited, because no one has found a “gene for intelligence” or for any behavioral trait.
This is one of those things that’s not even wrong. It is a red herring, and reflects a fundamental misunderstanding of genetics and what the genes do. Firstly, the genome is not like a shopping list, where there is a 1-to-1 correspondence between each “gene” and some physiological feature. Rather, the genes are like a recipe, and it is only through the complex interaction of all the genes do physical (and hence behavioral) traits emerge.
As such, most traits, especially behavioral ones (which are themselves just as “physical”; they depend on the physical structure of the brain) are polygenic. They depend on the action of many genes. This shouldn’t be surprising, since research shows that at least 84% of all genes are expressed primarily or exclusively in the brain (Ball, Gilbert, & Overly, 2012Hawrylycz et al, 2012).
Not only do the normal function of many traits depend on the action of many genes, but, more relevant here, differences in behavioral traits between different people depend on differences in many genes. Hence, the whole idea that there is a “gene for” X trait is generally foolhardy.
Though, it is true that we have had little luck pinpointing the relevant genetic variants that produce variation in intelligence or behavioral traits (so far). But then, that’s true for human height. We have only recently identified a few genetic variants that seem to have a role in height variation (Zhang, 2012), and they don’t explain much. Now, clearly, how tall you are is heavily dependent on your genes (height being as heritable as IQ), yet we have had a hard time finding which genes make the difference. Such is the case with most behavioral traits.
But here lies the fallacy: it is not necessary to know which genetic variants lead to variation in a trait to know that trait variation is affected by genetic variation. That’s like saying that you need to know the names of all the people who work in a factory to know that the people there produce widgets.
As we’ve seen, behavioral genetic methods confirm the very high heritability of intelligence and behavioral traits. “Classic” behavioral genetic methods, such as twin and adoption studies, were enough to establish this by themselves. However, as I said, in addition to these, newer methods, known as “Genome-wide Complex Trait Analyses” (GCTA) provide direct verification: these have showed that directly measured genetic similarity across large populations is related to variation in intelligence and many physical and behavioral traits. These unambiguously demonstrate that the genes under examination are related to trait variation, even if we don’t know which ones do so or how, exactly.
Broadly, differences between individuals and between groups can be pinned to genes that differ between individuals and between groups, even if we don’t which genes are doing the trick.
And even further, we do indeed have some links between certain genetic variants and behavioral variation. Many of these are detailed in The 10,000 Year Explosion, as well as in my post How Much Hard Evidence Do You Need?
7. Nobody knows what intelligence is, or how to measure it, and it is certainly not measured by IQ tests.
All wrong. We are still uncovering just what intelligence is, both in the abstract sense and in the case of intelligence in humans. But we certainly can measure it, and that is done very well by IQ tests.
This is a schematic layout of the findings of one particular investigation to the genetic architecture of IQ (Panizzon et al, 2014), and captures our basic findings on the matter. At the top, and behind all cognitive ability is a central “g” factor (initially for “general intelligence”), which is behind the various major mental domains, which themselves have an impact on specific tested abilities, as seen here.
The effectiveness of any mental endeavor, especially the more cognitively demanding ones (i.e., the ones that require you to “think”) will depend on an underlying mental “horsepower” so to speak. g is that horsepower.
As described in the paper, ability on a wide range of mental tasks will all tend to correlate with one another – i.e., if a person is good at one thing (like say math), they are likely to be reasonably good at a host of other things. Likewise, if a person is bad at something, chances are good that that person will be fairly bad at many other things (to varying degrees). There is great degree of individual variation in these, but a central pattern does emerge when you look at large numbers of people. It is from this that the g factor emerges.
An individual’s IQ score will tend to be stable – that is, repeat testing will tend to give roughly similar results. We all know of occasions where we have freak results from tests, but if you tended to test significantly above average in one instance, you are likely to keep getting scores on the high side.
But IQ is not something that exists only in a paper-and-pencil world or is limited to just the classroom. An individual’s IQ score will be predictive of their achievement. Most obviously in school, IQ predicts grades, as well as ultimate educational achievement. But IQ also predicts what sort of occupation you go on to take (as in say, architect versus sanitation worker) and how much you are likely to earn. People with higher IQs tend to find themselves in more prestigious careers and tend to make more money (again, with considerable individual variation – there is a lot of scatter around the score).People who are good at IQ tests are hardly only good at taking IQ tests.
Though it doesn’t stop there. IQ is predictive not just things one might imagine would be tied to “brainpower”, but a host of other things, like health, longevity, your chances of getting into trouble with the law, getting and staying married, even how tall, good-looking, and thin you are. (Indeed, the ghierarchy in the above depiction works for a host of other things past intellectual abilities.)
One might be tempted to conclude that perhaps the arrow of causation goes from good outcome -> IQ. Except that it’s clear that it doesn’t work that way. IQ doesn’t lend itself to much environmental manipulation – indeed, interventions that attempt to boost IQ have all met with failure. As well, IQ remains predictive even when measured in youth. It is predictive even when one controls for things like socioeconomic status (say during childhood). Indeed, the best control for this, looking at different siblings within a family, finds that IQ is predictive of real world outcomes between siblings – the sibling with the higher IQ tends to do better.
These are in addition to the fact that there are visible physiological correlates with IQ, such as head and brain size, as well various anatomical features of the brain, such as cortical thickness(Pietschnig et al, 2014Shaw et al, 2006Menary et al, 2013Karama, Deary, et al, 2011).
You may have heard that IQ can be distributed on a “bell curve”, and indeed, that’s one way of visualizing it (from Gottfredson, 1997) :


This is about what the distribution of IQ looks like (for a population with a mean of 100, like Northern Europeans). This gives you the relative frequencies of each level of IQ given that mean and standard deviation (15 points for most populations). You can see the type of occupations possible at each level. You also see the way people at different levels of IQ tend to learn. That stuff you heard about “learning styles” is generally rubbish. Whatever truth there is to it is primarily a function of IQ differences.
See also James Thompson on it: Psychological comments: The 7 tribes of intellect, well as my own post IQ and Death.
For much more on this, see again my page HBD Fundamentals: On the reality of IQ

8. Non-Whites score low on IQ tests because the tests are culturally biased.
Raven_Matrix.svgNo. Indeed, not all non-Whites score below “Whites” (as we’ve see above, hardly a monolithic category itself). East Asians, specifically those from China, Korea, and Japan, tend to outscore Northern Europeans on IQ tests, scoring in the 105 or so range, on average. Ashkenazi Jews also are found to outscore non-Jewish Whites, the former possessing an average IQ around 112. In the case of Blacks (that is, specifically, those of West African descent), they tend to do the best on culture-“loaded” IQ tests, and do significantly worse on more “culture-free” tests like the Raven’s Progressive Matrices (which use test questions like the one seen here). “Fresh off the boat” East Asian immigrants to the West don’t seem to have a problem with either IQ tests or eventual real-world performance.
Indeed, even more interestingly, IQ tests over-predict the performance of individuals from lower-scoring groups. That is, if the claim is that IQ tests are culturally biased against Blacks, for example, then they should perform worse on the intelligence test relative to their “true” intelligence. If so, then IQ tests would under-predict their real-world performance relative to Whites. But we see exactly the reverse! Blacks do worse in real-life than you would expect from their IQ scores alone. Cultural bias cannot be an explanation.
If this wasn’t enough, as we will see below, each racial/ethnic population performs roughly equally well no matter where in the world you look. It’s hard to reconcile a “cultural” bias that seems to be consistent across different cultures.

9. Poverty and/or discrimination are the causes of racial gaps intelligence.


Partly true, mostly false. An adverse environment, especially when we’re talking severe poverty – of the type you find in sub-Saharan Africa today – likely does have a deleterious effect on IQ. Hence, average IQ in sub-Saharan Africa is likely quite a bit lower than it would be under optimum conditions. However, we can’t reduce all racial IQ differences to environmental deprivation.
For one, racial gaps in IQ and achievement persist even in developed countries. Interventions, like Head Start, meant to ameliorate any educational deficits do nothing for the gap, as a comprehensive study by the U.S. government showed. As well, while income is correlated with IQ and educational attainment for all races, the relationship between childhood SES and IQ is different for different racial groups. Take a look at these (from here):



As we can see, on the SAT (which is simply another IQ test), the poorest Whites collectively outscored the wealthiest Blacks. As well, as we see, Blacks whose parents have graduate degrees are matched by Whites whose parents are only high school grads.
Even more interestingly, the group IQ and achievement hierarchy visible in the U.S. is found all over the world. All across the world, Blacks, for example – as a group –  generally do poorly versus Europeans. East Asians and Ashkenazi Jews collectively do well all around the world, better than Northern Europeans do. Across the globe and across very different societies and different economic systems, you see roughly the same pattern you do in the United States. One could attempt to piece together some “cultural” explanation for any particular society, but how to explain this global consistency, then? This is true with populations who have been in these respective countries for many generations, as is the case in Brazil, for instance.
Average IQ correlates very well with national development, in markers such as GDP per capita, say. Indeed, it is apparent that one of the primary determinants of national outcome is the average IQ of each nation’s population. This is why some countries lag behind despite decades of foreign aid and assistance, and why others have done well despite little by way of resources. One might then try to claim that a history of wealth is responsible for observed national IQs. However this too is untenable upon close examination. When looking at the outliers from this pattern, one can see that it is average IQ – and not average wealth – that predicts national outcomes. People from impoverished interior China, for example, do much better on IQ tests…

…than do people from wealthy yet not particularly intelligent Middle Eastern oil-exporting nations. Please see my post Welcome Readers from Portugal! for much more on this.
10. Charles Murray, Nicholas Wade, Richard Lynn, Steve Sailer, and all these other “race” scientists think all Black people are dumb and are criminals.
Totally false. No one who talks seriously about this believes that all individuals of any group are all anything (with perhaps very, very few traits excepted), especially not for continuously distributed traits like IQ, or criminality, etc. In all racial groups, there are individuals at almost every level for continuously distributed traits. That is, there are many smart Blacks (like myself, and most of my family) and many dumb Whites. The kicker is that the proportions of each vary from group to group, depending on the average of the trait for each group. See these:



The first is Gottfredson’s graphic, this time with the American Black and White IQ distribution displayed. The second is from Charles Murray’s and Richard Herrnstein’s 1994 book The Bell Curve, displaying the distribution as seen in one data set. As we can see, there is incredible overlap, but there are significant differences in the proportions, especially at the tail ends of the curves. This affects the fraction of each population scoring above or below some cutoff, as illustrated here (source):


As we can see, at passing level 1 (say an IQ of 100), 50% of one group scores above, whereas only 16% of the lower-mean group lies above. At passing level 2 (say an IQ of 115), 15% of the first group scores above, but only 2% of the second group does so, and so on. You see this pattern with many physical and behavioral traits that differ in aggregate between racial and ethnic groups, and researchers like Charles Murray or Richard Lynn are fully aware of this.
11. For more.
Please see my About Me page
Race, intelligence, and the biological basis of each are all very real. Biology is supremely important to all human differences. It is odd that we would think any different. Few people think that this is not true of non-human animals or other lifeforms. Why would this not be also true of humans? I leave you off with the definite viewing material, Norwegian filmmaker Harald Eia’s documentary Brainwash, the episode on race:







(Source: jaymans.wordpress.com/jaymans-race-inheritance-and-iq-f-a-q-f-r-b) votar

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