# Another Africa thread hijacked **URL:** \ **Category:** The BBQ Pit\ **Created:** [April 1, 2011, 1:04pm UTC](https://boards.straightdope.com/t/another-africa-thread-hijacked/576767 "2011-04-01T13:04:01Z")\ **Posts on this page:** 8\ **Page:** 30
**Author:** ![random6x7](https://avatars.discourse-cdn.com/v4/letter/r/8baadc/32.png) [@random6x7](https://boards.straightdope.com/u/random6x7)\ **Post date:** [April 18, 2011, 9:10pm UTC](https://boards.straightdope.com/t/another-africa-thread-hijacked/576767/581 "2011-04-18T21:10:46Z")
No. There are certain features that tend to show up in certain geographical areas. These features do not in any way line up like Neanderthal ones do. Again, one morphological feature does not make a race. Also, there are studies that show that some of the medical differences between races, besides the obviously genetic ones like sickle cell anemia, are due to culture, not race. For instance, black American women have babies of a lower birth weight than white American women. Black Caribbean women have babies of a similar birth weight as the white women, until they move to the US, where the weights drop to that of the American-born black women. Birth weight is partially a cultural phenomenon. Again, not every black person is susceptible to sickle cell anemia, and not every white person is immune. [Evolution - The theory of natural selection (part 2)](http://www.blackwellpublishing.com/ridley/tutorials/The_theory_of_natural_selection__part_2_8.asp) ---
**Author:** ![Chen019](https://avatars.discourse-cdn.com/v4/letter/c/f19dbf/32.png) [@Chen019](https://boards.straightdope.com/u/Chen019)\ **Post date:** [April 18, 2011, 9:27pm UTC](https://boards.straightdope.com/t/another-africa-thread-hijacked/576767/582 "2011-04-18T21:27:56Z")
> [@random6x7](#): > > No. There are certain features that tend to show up in certain geographical areas. These features do not in any way line up like Neanderthal ones do. Again, one morphological feature does not make a race. > > Also, there are studies that show that some of the medical differences between races, besides the obviously genetic ones like sickle cell anemia, are due to culture, not race. For instance, black American women have babies of a lower birth weight than white American women. Black Caribbean women have babies of a similar birth weight as the white women, until they move to the US, where the weights drop to that of the American-born black women. Birth weight is partially a cultural phenomenon. Again, not every black person is susceptible to sickle cell anemia, and not every white person is immune. [Evolution - The theory of natural selection (part 2)](http://www.blackwellpublishing.com/ridley/tutorials/The_theory_of_natural_selection__part_2_8.asp) Well no, but I’ve never heard anyone suggest that neanderthals/moderns are the benchmark for racial groups. One morphological feature doesn’t make a race, but [definitions](http://www.biology-online.org/dictionary/Race) look at sets of [features](http://www.ln.edu.hk/philoso/staff/sesardic/getfile.php?file=Race.pdf) that reflect shared ancestry. > [@](#): > > Indeed, a quick look into the literature confirms this. For instance, a study that covered 17 populations over the world and that relied on 34 different measurements managed to assign 98% of the specimens to their correct major racial group (Brues 1990, 6). Another more recent study had a success rate of 80% in distinguishing between American Whites and Blacks, although it used just two variables. With seven variables, however, it reached the reliability of 95%, and with 19 variables the probability of correct classification rose to 97% (Ousley et al. 2009). Also, estimating generally the reliability of attributing a given data point to one of the five racial categories, another team of experts calculated that under some realistic conditions it is sufficient to use as few as 13 characteristics to have the posterior probability of the correct classification attain the value of 99% (Konigsberg et al. 2009). ---
**Author:** ![random6x7](https://avatars.discourse-cdn.com/v4/letter/r/8baadc/32.png) [@random6x7](https://boards.straightdope.com/u/random6x7)\ **Post date:** [April 18, 2011, 10:49pm UTC](https://boards.straightdope.com/t/another-africa-thread-hijacked/576767/583 "2011-04-18T22:49:03Z")
I didn’t mean they were the benchmark. I was just pointing out the sort of thing you do see when there’s a discernable difference between two groups. Also, that article leaves out Ousley et al’s actual conclusions, which are that you can get a better than 80% chance of distinguishing between different groups of Europeans, or southern and northern Japanese. Why aren’t those, then, different races? We are good at placing people in their area of geographical origin (or their families’), but that doesn’t rely on race. We’re just as good if you think there are 3 races, 5, 11, or 500. So why is your racial classification system correct, and not a more fine-grained one? ---
**Author:** ![Belowjob2.0](https://avatars.discourse-cdn.com/v4/letter/b/b9e5f3/32.png) [@Belowjob2.0](https://boards.straightdope.com/u/Belowjob2.0)\ **Post date:** [April 19, 2011, 12:09am UTC](https://boards.straightdope.com/t/another-africa-thread-hijacked/576767/584 "2011-04-19T00:09:30Z")
> [@New\_Deal\_Democrat](#): > > The different human races differ as much and in the same way as different animal breeds. People of your persuasion claim that race is a social construct, but you usually support affirmative action. Why should those who imagine that they are Negro be given special preferences? What Colibri said. Also, there are specific reasons why human beings are much closer together genetically than different breeds of dog. New Deal Democrat, could you list some of those reasons? If you can’t, then you shouldn’t be talking about human evolution, because you don’t have the depth of knowledge to understand it. ---
**Author:** ![Chen019](https://avatars.discourse-cdn.com/v4/letter/c/f19dbf/32.png) [@Chen019](https://boards.straightdope.com/u/Chen019)\ **Post date:** [April 19, 2011, 12:15am UTC](https://boards.straightdope.com/t/another-africa-thread-hijacked/576767/585 "2011-04-19T00:15:23Z")
> [@random6x7](#): > > I didn’t mean they were the benchmark. I was just pointing out the sort of thing you do see when there’s a discernable difference between two groups. > > Also, that article leaves out Ousley et al’s actual conclusions, which are that you can get a better than 80% chance of distinguishing between different groups of Europeans, or southern and northern Japanese. Why aren’t those, then, different races? We are good at placing people in their area of geographical origin (or their families’), but that doesn’t rely on race. We’re just as good if you think there are 3 races, 5, 11, or 500. So why is your racial classification system correct, and not a more fine-grained one? You can easily find more [fine grained groups](http://mathildasanthropologyblog.files.wordpress.com/2009/04/snp.png) within the larger continental groupings. I’m just saying those major continental categories do reflect actual clusters because there was low gene flow. So someone from within those clusters is going to be more genetically similar to someone else from that cluster than someone from another [cluster/population](http://www.plosgenetics.org/article/info:doi/10.1371/journal.pgen.0010070). And the social categories you mention do correspond to [these pretty accurately](http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1196372/). ---
**Author:** ![random6x7](https://avatars.discourse-cdn.com/v4/letter/r/8baadc/32.png) [@random6x7](https://boards.straightdope.com/u/random6x7)\ **Post date:** [April 19, 2011, 1:15am UTC](https://boards.straightdope.com/t/another-africa-thread-hijacked/576767/586 "2011-04-19T01:15:27Z")
The four subgroups that last article used were for extremely disparate populations: Europeans, African Americans (who are generally west African mixed with white and maybe some American Indian), East Asian, and Hispanic. Those are, not coincidentally, the same groups that gave rise to the race concept. _Of course_ they look different and have a discrete set of traits. You’re looking at people who evolved thousands of miles away from each other! I am saying that, within those thousands of miles, the boundaries of the various traits get a hell of a lot more blurred. What would happen if they had tested people every hundred miles from Paris to Bangkok? There is no reasonable place to put a dividing line there, genetically or morphologically. You know the difference between red and orange, right? Where do you draw the line, though? What’s orange-red, what’s red-orange, where’s coral, and so on? Hell, many cultures don’t even distinguish between red and orange. Really, no one except really intense artists and decorators give a shit about those kinds of differences color-wise, but it makes a real impact when you talk about people. And that’s not even getting to the original argument, which is that IQ isn’t determined by your racial genetics. To recap: IQ is a flawed concept. Race as a biological category is a flawed concept. The idea that intelligence is purely or even mostly genetic, also flawed. ---
**Author:** ![Chen019](https://avatars.discourse-cdn.com/v4/letter/c/f19dbf/32.png) [@Chen019](https://boards.straightdope.com/u/Chen019)\ **Post date:** [April 19, 2011, 2:12am UTC](https://boards.straightdope.com/t/another-africa-thread-hijacked/576767/587 "2011-04-19T02:12:14Z")
> [@random6x7](#): > > The four subgroups that last article used were for extremely disparate populations: Europeans, African Americans (who are generally west African mixed with white and maybe some American Indian), East Asian, and Hispanic. Those are, not coincidentally, the same groups that gave rise to the race concept. _Of course_ they look different and have a discrete set of traits. You’re looking at people who evolved thousands of miles away from each other! I am saying that, within those thousands of miles, the boundaries of the various traits get a hell of a lot more blurred. What would happen if they had tested people every hundred miles from Paris to Bangkok? There is no reasonable place to put a dividing line there, genetically or morphologically. You know the difference between red and orange, right? Where do you draw the line, though? What’s orange-red, what’s red-orange, where’s coral, and so on? Hell, many cultures don’t even distinguish between red and orange. Really, no one except really intense artists and decorators give a shit about those kinds of differences color-wise, but it makes a real impact when you talk about people. > > And that’s not even getting to the original argument, which is that IQ isn’t determined by your racial genetics. To recap: IQ is a flawed concept. Race as a biological category is a flawed concept. The idea that intelligence is purely or even mostly genetic, also flawed. Well, again - you get clusters because there are points of geographic separation (across oceans, the Himalayas, and the Sahara etc). That is why those [clusters](http://www.plosgenetics.org/article/info:doi/10.1371/journal.pgen.0010070)arise. As Rosenberg writes: > [@](#): > > For population pairs from the same cluster, as geographic distance increases, genetic distance increases in a linear manner, consistent with a clinal population structure. However, for pairs from different clusters, genetic distance is generally larger than that between intracluster pairs that have the same geographic distance. For example, genetic distances for population pairs with one population in Eurasia and the other in East Asia are greater than those for pairs at equivalent geographic distance within Eurasia or within East Asia. Loosely speaking, it is these small discontinuous jumps in genetic distance—across oceans, the Himalayas, and the Sahara—that provide the basis for the ability of STRUCTURE to identify clusters that correspond to geographic regions. You’re right that there are blurry or fuzzy boundaries you’re not talking about different species. That doesn’t mean there are no [meaningul](http://www.nejm.org/doi/full/10.1056/NEJMsb025007) groups or categories. > [@random6x7](#): > > And that’s not even getting to the original argument, which is that IQ isn’t determined by your racial genetics. To recap: IQ is a flawed concept. Race as a biological category is a flawed concept. The idea that intelligence is purely or even mostly genetic, also flawed. 1. [Genes vary in frequency across groups](http://infoproc.blogspot.com/2007/01/metric-on-space-of-genomes-and.html). So it’s not surprising that you see statistical differences. 2. There is no question that iq varies statistically across groups. The causation question is what is in dispute. 3. Whether you think it is a flawed concept or not, it has predictive validity across groups. [Steven Pinker](http://www.nytimes.com/2009/01/11/magazine/11Genome-t.html?_r=1&pagewanted=2) points out: > [@](#): > > To study something scientifically, you first have to measure it, and psychologists have developed tests for many mental traits. And contrary to popular opinion, the tests work pretty well: they give a similar measurement of a person every time they are administered, and they statistically predict life outcomes like school and job performance, psychiatric diagnoses and marital stability. 1. Variation in intelligence is due to both genetic & environmental variation. [Pinker again](http://www.nytimes.com/2009/01/11/magazine/11Genome-t.html?_r=1&pagewanted=2): > [@](#): > > The most prominent finding of behavioral genetics has been summarized by the psychologist Eric Turkheimer: “The nature-nurture debate is over. . . . All human behavioral traits are heritable.” By this he meant that a substantial fraction of the variation among individuals within a culture can be linked to variation in their genes. Whether you measure intelligence or personality, religiosity or political orientation, television watching or cigarette smoking, the outcome is the same. Identical twins (who share all their genes) are more similar than fraternal twins (who share half their genes that vary among people). Biological siblings (who share half those genes too) are more similar than adopted siblings (who share no more genes than do strangers). And identical twins separated at birth and raised in different adoptive homes (who share their genes but not their environments) are uncannily similar. Also, see this recent Melbourne [study](http://www.cosmosmagazine.com/node/4129/full): > [@](#): > > “While we observed strong genetic effects on cost-efficiency of the entire brain, we also found that specific parts of the brain varied considerably in the degree to which their wiring was under genetic control.” said Fornito. > > “We found some of the strongest effects in the prefrontal cortex, where up to 80% of the differences between people were attributable to genes. The prefrontal cortex plays a vital role in planning, strategic thinking, decision-making and memory.” ---
**Author:** ![GIGObuster](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/gigobuster/32/421_2.png) [@GIGObuster](https://boards.straightdope.com/u/GIGObuster)\ **Post date:** [April 19, 2011, 3:38am UTC](https://boards.straightdope.com/t/another-africa-thread-hijacked/576767/588 "2011-04-19T03:38:09Z")
[http://geniusblog.davidshenk.com/2009/01/steven-pinkers-probabilistic-genes.html](http://geniusblog.davidshenk.com/2009/01/steven-pinkers-probabilistic-genes.html) > [@](#): > > Turkheimer did say that. The quote is correct. But Turkheimer has produced a study showing close to zero heritability with respect to some of these same traits. Heritability studies are frought with complexity and ambiguity. Pinker must know this and is choosing for some reason not to acknowledge it. The last line in the paragraph above is particularly problematic. I’m trying to choose my words carefully, but I would go so far as to say that Pinker’s sentence is more false than true. Yes, some identical twins separated at birth have some uncanny similarities – but many of them also turn out to have not actually been separated at birth. Others are not similar at all. > [@](#): > > If you read his caveats elsewhere very carefully, he backtracks by saying that a lot of different elements go into it. But in the public explanation of science, it’s all a matter of emphasis and Pinker’s emphasis is clear. He’s still spending most of his energy trying to fight against the blank-slaters who once-upon-a-time naively argued against any genetic influence whatever. We’re past that argument now – or should be. We know that genes influence everything but directly determine very little. We know that most traits, particularly complex character traits and abilities, are the consequence of development. From the moment of conception, genes interact with the environment. People are not born with fixed IQs. Talents are not determined by a genetic lottery. Each one of us is conceived with immense potential. > > The nature-nurture debate has not been settled in favor of nurture, as Pinker implies. It’s been rendered obsolete. As even Pinker notices in the end: > [@](#): > > Even if personal genomics someday delivers a detailed printout of psychological traits, it will probably not change everything, or even most things. It will give us deeper insight about the biological causes of individuality, and it may narrow the guesswork in assessing individual cases. But the issues about self and society that it brings into focus have always been with us. We have always known that people are liable, to varying degrees, to antisocial temptations and weakness of the will. We have always known that people should be encouraged to develop the parts of themselves that they can (“a man’s reach should exceed his grasp”) but that it’s foolish to expect that anyone can accomplish anything (“a man has got to know his limitations”). And we know that holding people responsible for their behavior will make it more likely that they behave responsibly. “My genes made me do it” is no better an excuse than “We’re depraved on account of we’re deprived.” > > Many of the dystopian fears raised by personal genomics are simply out of touch with the complex and probabilistic nature of genes. Forget about the hyperparents who want to implant math genes in their unborn children, the “Gattaca” corporations that scan people’s DNA to assign them to castes, the employers or suitors who hack into your genome to find out what kind of worker or spouse you’d make. Let them try; they’d be wasting their time. And so are you Chen019. [Previous page](https://boards.straightdope.com/t/another-africa-thread-hijacked/576767.md?page=29)