In reevaluating Morton and Gould, we do not dispute that racist views were unfortunately common in 19th-century science or that bias has inappropriately influenced research in some cases. Furthermore, studies have demonstrated that modern human variation is generally continuous, rather than discrete or ″racial,″ and that most variation in modern humans is within, rather than between, populations. In particular, cranial capacity variation in human populations appears to be largely a function of climate, so, for example, the full range of average capacities is seen in Native American groups, as they historically occupied the full range of latitudes, say the study authors.
I likewise do not dispute the colour orange has no clear discrete border to the colour red, and that indeed both are a social construct. This seems an implicit appeal to Lewontin’s fallacy. Though in this case it seems almost like a half-hearted ritual denunciation put there as safety precaution because they are criticising the, in debates oft cited, saint Gould.
When thinking about the climate and cranial capacity connection the most likley explanations seems to be simply that cold clime, all else being equal, requires, more smarts, but please note that it is also possible that cranial capacities vary due to the problem of temperature regulation of the brain (the relationship between surface and volume matters in this sort of thinking).
When thinking about the climate and cranial capacity connection the most likley explanations seems to be simply that cold clime, all else being equal, requires, more smarts, but please note that it is also possible that cranial capacities vary due to the problem of temperature regulation of the brain (the relationship between surface and volume matters in this sort of thinking).
Another alternative explanation that has surfaced (paper) is that both bigger eyes and bigger brains developed in order to deal with the low light condition. Commentary on the study, by Peter Frost:
The logjam seems to have broken. On the heels of Lewis et al. (2011), we now have another paper on variation in brain size among human populations, this time by Pearce and Dunbar (2011).
Brains vary in size by latitude, being bigger at higher latitudes and smaller at lower ones. This variation seems to reflect an adaptation to climate. But just how, exactly, does climate relate to brain size? How direct or indirect is the relationship?
Pearce and Dunbar (2011) argue that bigger brains are an adaptation to lower levels of ambient light. Specifically, dimmer light requires larger eyes, which in turn require larger visual cortices in the brain. Using 73 adult crania from populations located at different latitudes, the two authors found that both eyeball size and brain size correlate positively with latitude. The correlation was stronger with eyeball size, an indication that this factor was driving the increase in brain size.
How credible is this explanation? First of all, visual cortex size was not directly measured. The authors inferred that this brain area was responsible for the increase in total cranial capacity. Obviously, they couldn’t have done otherwise. They were measuring skulls, not intact brains.
But there’s another problem—one in the realm of logic. A lot of things correlate with latitude: pigmentation, mating systems, rules of descent, degree of paternal investment, and so on. If one of them correlates more strongly with latitude than the others, does it therefore cause the others? Not at all. It may be closer than the others to this shared cause, but it doesn’t necessarily lie on the same causal chain as the others.
In other words, the level of ambient light does not produce a single cascade of consequences, with eyeball size being the first consequence. There are probably many different cascades.
To date, the best map of human variation in brain size is the one by Beals et al. (1984) (see previous post). If dimness of light is the main determinant, brain size should be highest in northwestern Europe, northern British Columbia, the Alaskan panhandle, and western Greenland. These regions combine high latitudes with generally overcast skies. Yet they are not the regions where humans have the biggest brains. Instead, brain size is at its highest among humans from the northern fringe of Arctic Asia and from northeastern Arctic Canada. These regions are, if anything, less overcast than average. They often have high levels of ambient light because of reflection from snow and ice.
The jury is still out on this question. I suspect, however, that the following three factors probably explain variation in brain size with latitude.
Among hunter-gatherers, hunting distance increases with latitude because there are fewer game animals per square kilometer (Hoffecker, 2002, pp. 8-9). Hunters must therefore store larger amounts of spatiotemporal information (landmarks, previous hunting itineraries, mental simulations of possible movements by game animals over space and time). This factor might explain why brains have grown smaller since the advent of agriculture.
The seasonal cycle matters more at higher latitudes. As a result, northern hunter-gatherers, and northern agriculturalists even more so, must plan ahead for the next season (or even for the season after the next one).
Women gather less food at higher latitudes and almost none in the Arctic. They are thus free to specialize in other tasks, such as garment making, food processing, and shelter building. This “family workshop” creates opportunities for greater technological complexity, which in turn increases selection for greater cognitive performance.
I suspect bigger brains provide not so much greater intelligence as greater ability to store information. As such, they nonetheless pre-adapted northern hunter-gatherers for later advances in cultural evolution.
What I find surprising is that human eyes size increases further from the equator, this is something I think I’ve never heard of before.
Temperature regulation aspects might rate more highly as an influencing factor than one would think. Large bodies (and probably the head in particular) would be more resistant to hypothermia, whereas small bodies would be more resistant to heat-stroke.
Regardless of why, animals definitely do become larger further north and the brain size seems to follow the body size quite closely without much impact on intelligence. I don’t know if arctic animals are quite on the scaling line. They do seem a bit smarter.
(The point of this comment is just to disentangle theory from observation.)
Regardless of why, animals definitely do become larger further north and the brain size seems to follow the body size quite closely without much impact on intelligence. I don’t know if arctic animals are quite on the scaling line. They do seem a bit smarter.
If I’m reading this right, the brain-to-body mass ratio dosen’t change?
I was not claiming that. That is the thing I said I don’t know: “I don’t know if arctic animals are quite on the scaling line.” This is a precise question about data is that has been collected. I just don’t know what the data says. I’m not sure what I meant by “quite.” When animals diverge from the scaling line, like primates, corvids, and dolphins, they move to parallel scaling line, not far from the main line.
Incidentally, the scaling line is not a constant brain to body mass ratio, but that the brain mass is a constant multiple of the 3/4th power of the body mass.
See now, this layman couldn’t tell from Wikipedia why Edwards’ critique actually contradicts what the intro calls the main point of Lewontin. Edit: I mean the section on Lewontin’s argument.
It would seem very odd if a sufficiently knowledgeable geneticist couldn’t tell a person’s natural skin color from their genes with near 100% reliability. Melanin clearly has a strong genetic component, as do other physical features that correlate with melanin. We want to know if it correlates with any interesting genetic differences.
Melanin clearly has a strong genetic component, as do other physical features that correlate with melanin. We want to know if it correlates with any interesting genetic differences.
Well, rather obviously it correlates with all sorts of things: not having red hair, or blue eyes, or blond hair, or straight hair, not being an Ashkenazi Jew, and not being able to digest milk. What would you find “interesting”, though?
Melanin clearly has a strong genetic component, as do other physical features that correlate with melanin. We want to know if it correlates with any interesting genetic differences.
A priori unlikely—skin colour is strongly selected for just on its own—near the equator you need melanin for protection from the sun, in high latitudes you need a lack of it to get Vitamin D—so Africans have lots of the stuff despite having the widest genetic variance per area of all humans. (That linked paper uses this fact to support their assertion that east Africa is where humans come from - it’s a standard expectation that variance is greatest near the origin).
“Race” is a magical category that does not carve the gene pool at its joints. It’s a social categorisation pretending to be a genetic one. e.g. Anyone who regards “negro” as a genetic grouping, on a par with Ashkenazim or Icelanders, has just invoked a magical category and needs to be led gently through charts of genetic variance per area.
When measuring effects of melanin, did they measure Indians as well?
“Race” is a magical category that does not carve the gene pool at its joints. It’s a social categorisation pretending to be a genetic one.
That doesn’t matter so long as people use “race” to refer to “phenotypic” categorizations rather than genetic categorizations. People don’t care if differences between races have a genetic origin, they just care about having roughly correct cached priors for predicting stereotypical behaviors/traits based on skin color, presence or absence of epicanthic folds, et cetera. In practice these priors are roughly as informative as those for clothing choice and the environment of interaction for predicting behaviors. The vast majority of people have no reason to care that Africa has a ton of genetic diversity, it’s practically useless information. Race categorization, on the other hand, is not useless.
(It is very important to note that the above is descriptive and not normative.)
In practice these priors are roughly as informative as those for clothing choice and the environment of interaction for predicting behaviors.
That’s what I meant by it being a social category. A social category with a visible marker! At least the Burakumin can hide in plain sight.
The other problem with the usual question “race and intelligence” (which usually seems to start at “black Americans and intelligence”) is that our tool to measure intelligence is IQ tests. Although a 10-point IQ difference within one social group that e.g. correlates with lead in paint is something to worry about lots, it’s ridiculously easy to get 15 points’ difference between groups for really obviously social and cultural factors (e.g. Burakumin). So if you’re measuring IQ between groups, a difference of 15 points or less may well be cultural. And then there’s the Flynn effect, which could be culture or food.
The x axis is a genetic magical category, the y axis is incredibly shaky and people are way invested in the answers. What could possibly go wrong?
The best evidence available today indicates that this is simply false. A recent systematic literature review of Africans’ performance on IQ tests other than Raven’s Progressive Matrices finds an average IQ of around 82. An analogous review of results from Africans who took the Raven’s Progressive Matrices finds a similar average of about 80.
I think that’s false. African Americans are about 20% European in ancestry if memory serves. Of course if eugenic selection did its work, some high IQ alleles may have escaped the “neutral” baggage from the Native American and European gene pool.
Lynn’s exact numbers, while spot on the general pattern, have been criticized by others. There are a some studies that point to an actual IQ (that try to estimate the effects of things like people being unused to using a pencil or solving the test in a nonnative lanugage) nearer to that of 75 and a handful even something as high as 80.
Regression to the mean of the children of African immigrants in Europe, points to a 80ish IQ once environmental advantages kick in.
Citation? If this were a well established finding without known flaws in its methodology, I would expect it to come up a lot in race/intelligence discussions, but this is the first I’ve heard of it.
This seems extremely implausible. Would a group with intelligence as low as an average IQ of 70 connotes be able to maintain language at the same level as most human groups?
I think you don’t have a clear picture of how highly functional low IQ people can be. This is in sense natural, since I mean how many people with an IQ of 70 do you know? Its silly but I sometimes have to remind myself they are by definition as common as people with an IQ of 130. They hold jobs and they manage to reproduce just fine, so they aren’t exactly the helpless drooling passives that popular imagination paints them as.
Also I think its often underestimated how different low IQ people of different types can be from each other.
Can a 13 year old learn to drive a car safely? Yes. Can he work in a factory? Yes. Can he run a farm? Yes. Can he be a soldier? Yes. Can a group of 13 year old children use lanugage at basically the same level as most human groups? Yes.
But how well would a 13 year old do compared to 18 year old on a IQ test? Not that well I suspect.
If the test got mislabelled as that of a 18 year old, what would be his estimated IQ? In abstract thinking he may not be that better than a 18 year old with a 70ish IQ but in many many other regards the test wouldn’t do him justice by putting him in the same category.
Black job performance is slightly better than what would be expected going just by their IQs. And Blacks with IQs in the 70s are generally on average more functional than Whites or East Asians with the same IQ. This has been the basis of some speculation that low IQ Whites and East Asians do worse on average because the sample contains not only people who are plain dumb, but a greater fraction people who suffer from other disabilities and more general brain damage (and/or underdevelopment) too, than is found in the group of IQ 70 Blacks.
Funnily enough, I recently posted some comments on exactly the IQ 70 Africa claim against the usual view that that is impossible, quoting a LWer’s blog post about working in Haiti:
“It has proven hard for me to appreciate exactly how confused the Haitians are about some things. Gail, our program director, explained that she has a lot of trouble with her Haitian office staff because they don’t understand the concept of sorting numerically. Not just “they don’t want to do it” or “it never occurred to them”, but after months and months of attempted explanation they don’t understand that sorting alphabetically or numerically is even a thing. Not only has this messed up her office work, but it makes dealing with the Haitian bureaucracy—harrowing at the best of times—positively unbearable. Gail told the story of the time she asked a city office for some paperwork regarding Doctors Without Borders. The local official took out a drawer full of paperwork and looked through every single paper individually to see if it was the one she wanted. Then he started looking for the next drawer. After five hours, the official finally said that the paper wasn’t in his office.”
Farming, simple irrigation systems, pottery and other crafts (with objects of great beauty made for the upper class), walled cities, some siege engines, long distance trade, domestication of animals, iron working, sailing, class divisions, chariots and writing.
This they could all eventually develop with no input from the outside in favourable climactic conditions.
Exposed to outside influence I think they can pick up things like clockwork, ocean worthy ships, machine tools, the internal combustion engine, radio and television (and improve it on their own as well). Even basic nuclear technology, computers and some complex medical equipment isn’t completely out of the picture, though don’t expect any refinements. As a society they can probably get clean water, electrification, good roads, decent hospitals, reasonable safety from crime and quality primary school education.
This is what I’d expect of a civilization with an average IQ of 70. But please remember this civilization requires some adaptation, what I wrote goes for a “civilized” people (or at least a people that practised farming for some time) with an IQ of 70. Not all hunter gatherer populations with that IQ would be able to make this work. Self-domestication in humans isn’t really primarily about raising IQ as some people assume it is.
I read this interesting quote today, and I couldn’t help but remember your car example:
Third, Flynn may be overestimating the average population intelligence in past centuries and the amount of g needed to function in an agricultural society. Humans have much genetic programming for normal everyday life tasks (such as propensities to quickly learn a language and social skills) and drawbacks of low g may only become evident with arbitrary, unnatural tasks, such as school learning. The phenomenon of “six hour retardation” mentioned earlier suggests that people diagnosed as retarded by IQ tests may have trouble with school work but function adequately even in a technological society. After school, they “disappear into the population”. Indeed, rightly or wrongly, rulers and political writers in past centuries have expressed contempt for the abilities of the masses. When cars were invented, some stated that few people had the intellectual capacity to learn to drive them. Such comments are rare today.
I think you don’t have a clear picture of how highly functional low IQ people can be.
But how highly functional are low-IQ people on average? Looking at only the most functional low-IQ people wouldn’t give a good idea of what to expect in general.
But how well would a 13 year score compared to 18 year old on a IQ test? Not that well I suspect.
The 13-year-old’s raw score would generally be lower, but their IQ should be about the same as the 18-year-old’s; IQ tests are age-normed nowadays.
But how highly functional are low-IQ people on average? Looking at only the most functional low-IQ people wouldn’t give a good idea of what to expect in general.
My point was that different groups of people that might score low on IQ tests sometimes differ systematically from each other. In my last paragraph I suggest quite directly IQ 70 Black people are different from IQ 70 Whites and East Asians.
The 13-year-old’s raw score would generally be lower, but their IQ should be about the same as the 18-year-old’s; IQ tests are age-normed nowadays.
Well aware of this. Hence:
If the test got mislabelled as that of a 18 year old, what would be his estimated IQ? In abstract thinking he may not be that better than a 18 year old with a 70ish IQ but in many many other regards the test wouldn’t do him justice by putting him in the same category.
genetic grouping, on a par with Ashkenazim or Icelanders
Knowing that someone has substantial Ashkenazim ancestry lets you make many probabilistic predictions about both neutral and significant genetic variations (e.g. diseases, lactose tolerance, etc). This is because of the fact that historically mating behavior was highly nonrandom across geographical and ethnic lines. Since selection pressures and new mutations varied by region (see lactose tolerance, malaria resistance, fast-twitch muscle, salt retention, etc, etc) the differences predicted are enriched for differences due to natural selection, i.e. interesting ones that actually made life-or-death differences in the past.
Learning that someone is of European Ashkenazi descent lets us (probabilistically) predict a variety of genetic differences from the European average at each of many loci, and to very accurately predict, in the aggregate, a systematic skew across many loci to the Ashkenazim distribution.
“Race” is a magical category that does not carve the gene pool at its joints.
This is just factually wrong. You can use many, many different traits, or just neutral variation to easily cluster humans in a high-dimensional space of genetic variance. The oceans, the Sahara desert, the steppes, and other geographical features were major factors in historical reproductive isolation, and the largest (and quite clear) clusters correspond pretty well to the old anthropological classifications. If you tell me some facts about bone structure, body fat ratio, malaria resistance genes, whatever, I can quickly assign high probability to a given mix of recent continental ancestry for an individual and make much better predictions about other traits using that info than I could without using that clustering. In the U.S., self-identified race is itself a very strong predictor of continental ancestry, and if one supplements with further questions about grandparents’ race or asks about multiracial ancestry it gets even better.
This post by physicist Steve Hsu discusses the topic well, also see this paper by Risch et al:
Knowing that someone has substantial Ashkenazim ancestry lets you make many probabilistic predictions about both neutral and significant genetic variations
Yes, that’s what I meant—they’re an actually close-knit genetic group. “Negro” is not. “Black American” is a little closer, but not much (their African ancestors having been taken as slaves mostly from the west coast) - you’ll see obviously highly selected-for factors, like black skin and sickle-cell.
There are people who identify as black or who are identified as black under a “one drop” rule. This doesn’t seem as though it would give huge amounts of information about associated traits.
For example, a lot of phenotypes would get classified as “black” in the American race structure, and “white, somewhat mixed” in the West European one. In the US, there’s a category called “Asian” with covers both East and South Asians. Two people in the US with the same ancestry and physical appearance may get classified as either white or Native American depending on their ties with a tribe. And so on.
Sure, “race” divides people according to physical appearance, ancestors, and culture, so it has a strong genetic component. But it’s not solely genetic, and inasmuch as it is, it’s still bad genetics, like the distinction between fish-and-dolphins and mammals is bad taxonomy.
I likewise do not dispute the colour orange has no clear discrete border to the colour red, and that indeed both are a social construct. This seems an implicit appeal to Lewontin’s fallacy. Though in this case it seems almost like a half-hearted ritual denunciation put there as safety precaution because they are criticising the, in debates oft cited, saint Gould.
When thinking about the climate and cranial capacity connection the most likley explanations seems to be simply that cold clime, all else being equal, requires, more smarts, but please note that it is also possible that cranial capacities vary due to the problem of temperature regulation of the brain (the relationship between surface and volume matters in this sort of thinking).
Mr Johnson, sir, there you are! The lab boys have been looking for you. They say they’ve figured out where the missing personality core got to!
Another alternative explanation that has surfaced (paper) is that both bigger eyes and bigger brains developed in order to deal with the low light condition. Commentary on the study, by Peter Frost:
What I find surprising is that human eyes size increases further from the equator, this is something I think I’ve never heard of before.
Temperature regulation aspects might rate more highly as an influencing factor than one would think. Large bodies (and probably the head in particular) would be more resistant to hypothermia, whereas small bodies would be more resistant to heat-stroke.
Regardless of why, animals definitely do become larger further north and the brain size seems to follow the body size quite closely without much impact on intelligence. I don’t know if arctic animals are quite on the scaling line. They do seem a bit smarter.
(The point of this comment is just to disentangle theory from observation.)
If I’m reading this right, the brain-to-body mass ratio dosen’t change?
I was not claiming that. That is the thing I said I don’t know: “I don’t know if arctic animals are quite on the scaling line.” This is a precise question about data is that has been collected. I just don’t know what the data says. I’m not sure what I meant by “quite.” When animals diverge from the scaling line, like primates, corvids, and dolphins, they move to parallel scaling line, not far from the main line.
Incidentally, the scaling line is not a constant brain to body mass ratio, but that the brain mass is a constant multiple of the 3/4th power of the body mass.
Ok than you for clearing that up (up vote), I hope you didn’t mind me asking since I wasn’t sure if I understood the comment properly or not. :)
See now, this layman couldn’t tell from Wikipedia why Edwards’ critique actually contradicts what the intro calls the main point of Lewontin. Edit: I mean the section on Lewontin’s argument.
It would seem very odd if a sufficiently knowledgeable geneticist couldn’t tell a person’s natural skin color from their genes with near 100% reliability. Melanin clearly has a strong genetic component, as do other physical features that correlate with melanin. We want to know if it correlates with any interesting genetic differences.
Well, rather obviously it correlates with all sorts of things: not having red hair, or blue eyes, or blond hair, or straight hair, not being an Ashkenazi Jew, and not being able to digest milk. What would you find “interesting”, though?
A priori unlikely—skin colour is strongly selected for just on its own—near the equator you need melanin for protection from the sun, in high latitudes you need a lack of it to get Vitamin D—so Africans have lots of the stuff despite having the widest genetic variance per area of all humans. (That linked paper uses this fact to support their assertion that east Africa is where humans come from - it’s a standard expectation that variance is greatest near the origin).
“Race” is a magical category that does not carve the gene pool at its joints. It’s a social categorisation pretending to be a genetic one. e.g. Anyone who regards “negro” as a genetic grouping, on a par with Ashkenazim or Icelanders, has just invoked a magical category and needs to be led gently through charts of genetic variance per area.
When measuring effects of melanin, did they measure Indians as well?
That doesn’t matter so long as people use “race” to refer to “phenotypic” categorizations rather than genetic categorizations. People don’t care if differences between races have a genetic origin, they just care about having roughly correct cached priors for predicting stereotypical behaviors/traits based on skin color, presence or absence of epicanthic folds, et cetera. In practice these priors are roughly as informative as those for clothing choice and the environment of interaction for predicting behaviors. The vast majority of people have no reason to care that Africa has a ton of genetic diversity, it’s practically useless information. Race categorization, on the other hand, is not useless.
(It is very important to note that the above is descriptive and not normative.)
That’s what I meant by it being a social category. A social category with a visible marker! At least the Burakumin can hide in plain sight.
The other problem with the usual question “race and intelligence” (which usually seems to start at “black Americans and intelligence”) is that our tool to measure intelligence is IQ tests. Although a 10-point IQ difference within one social group that e.g. correlates with lead in paint is something to worry about lots, it’s ridiculously easy to get 15 points’ difference between groups for really obviously social and cultural factors (e.g. Burakumin). So if you’re measuring IQ between groups, a difference of 15 points or less may well be cultural. And then there’s the Flynn effect, which could be culture or food.
The x axis is a genetic magical category, the y axis is incredibly shaky and people are way invested in the answers. What could possibly go wrong?
But, American “blacks” have a 15 point difference because they’re [EDIT] about 20% European. Africans have average IQs of 70.
[EDIT]: Citation (see also), though I should note that it is questioned.
The best evidence available today indicates that this is simply false. A recent systematic literature review of Africans’ performance on IQ tests other than Raven’s Progressive Matrices finds an average IQ of around 82. An analogous review of results from Africans who took the Raven’s Progressive Matrices finds a similar average of about 80.
I think that’s false. African Americans are about 20% European in ancestry if memory serves. Of course if eugenic selection did its work, some high IQ alleles may have escaped the “neutral” baggage from the Native American and European gene pool.
Lynn’s exact numbers, while spot on the general pattern, have been criticized by others. There are a some studies that point to an actual IQ (that try to estimate the effects of things like people being unused to using a pencil or solving the test in a nonnative lanugage) nearer to that of 75 and a handful even something as high as 80.
Regression to the mean of the children of African immigrants in Europe, points to a 80ish IQ once environmental advantages kick in.
Citation? If this were a well established finding without known flaws in its methodology, I would expect it to come up a lot in race/intelligence discussions, but this is the first I’ve heard of it.
American “blacks” aren’t about half European anyway, they’re less than 20% European on average.
This seems extremely implausible. Would a group with intelligence as low as an average IQ of 70 connotes be able to maintain language at the same level as most human groups?
I think you don’t have a clear picture of how highly functional low IQ people can be. This is in sense natural, since I mean how many people with an IQ of 70 do you know? Its silly but I sometimes have to remind myself they are by definition as common as people with an IQ of 130. They hold jobs and they manage to reproduce just fine, so they aren’t exactly the helpless drooling passives that popular imagination paints them as.
Also I think its often underestimated how different low IQ people of different types can be from each other.
Can a 13 year old learn to drive a car safely? Yes. Can he work in a factory? Yes. Can he run a farm? Yes. Can he be a soldier? Yes. Can a group of 13 year old children use lanugage at basically the same level as most human groups? Yes.
But how well would a 13 year old do compared to 18 year old on a IQ test? Not that well I suspect.
If the test got mislabelled as that of a 18 year old, what would be his estimated IQ? In abstract thinking he may not be that better than a 18 year old with a 70ish IQ but in many many other regards the test wouldn’t do him justice by putting him in the same category.
Black job performance is slightly better than what would be expected going just by their IQs. And Blacks with IQs in the 70s are generally on average more functional than Whites or East Asians with the same IQ. This has been the basis of some speculation that low IQ Whites and East Asians do worse on average because the sample contains not only people who are plain dumb, but a greater fraction people who suffer from other disabilities and more general brain damage (and/or underdevelopment) too, than is found in the group of IQ 70 Blacks.
Funnily enough, I recently posted some comments on exactly the IQ 70 Africa claim against the usual view that that is impossible, quoting a LWer’s blog post about working in Haiti:
You’re right. I was posting from a position of considerable ignorance about what low IQs might mean in practice.
What would you expect to see from a civilization with an average IQ of 70?
Farming, simple irrigation systems, pottery and other crafts (with objects of great beauty made for the upper class), walled cities, some siege engines, long distance trade, domestication of animals, iron working, sailing, class divisions, chariots and writing.
This they could all eventually develop with no input from the outside in favourable climactic conditions.
Exposed to outside influence I think they can pick up things like clockwork, ocean worthy ships, machine tools, the internal combustion engine, radio and television (and improve it on their own as well). Even basic nuclear technology, computers and some complex medical equipment isn’t completely out of the picture, though don’t expect any refinements. As a society they can probably get clean water, electrification, good roads, decent hospitals, reasonable safety from crime and quality primary school education.
This is what I’d expect of a civilization with an average IQ of 70. But please remember this civilization requires some adaptation, what I wrote goes for a “civilized” people (or at least a people that practised farming for some time) with an IQ of 70. Not all hunter gatherer populations with that IQ would be able to make this work. Self-domestication in humans isn’t really primarily about raising IQ as some people assume it is.
I read this interesting quote today, and I couldn’t help but remember your car example:
--Howard 2001 Searching the Real World for Signs of Rising Population Intelligence
(This leads to a provocative thesis which I find amusing just to contemplate.)
But how highly functional are low-IQ people on average? Looking at only the most functional low-IQ people wouldn’t give a good idea of what to expect in general.
The 13-year-old’s raw score would generally be lower, but their IQ should be about the same as the 18-year-old’s; IQ tests are age-normed nowadays.
My point was that different groups of people that might score low on IQ tests sometimes differ systematically from each other. In my last paragraph I suggest quite directly IQ 70 Black people are different from IQ 70 Whites and East Asians.
Well aware of this. Hence:
Fair enough. I misread the bolded part of your post as just amplifying a more general point about younger people scoring lower on IQ tests.
Didn’t the eggheads say back in 1994 that it wasn’t due to cultural bias?
Wow its sounds dumber when I quote them.
Heck, what do I know? I can’t be bothered to read more than one page on this stuff. Got my info from this flyer.
Knowing that someone has substantial Ashkenazim ancestry lets you make many probabilistic predictions about both neutral and significant genetic variations (e.g. diseases, lactose tolerance, etc). This is because of the fact that historically mating behavior was highly nonrandom across geographical and ethnic lines. Since selection pressures and new mutations varied by region (see lactose tolerance, malaria resistance, fast-twitch muscle, salt retention, etc, etc) the differences predicted are enriched for differences due to natural selection, i.e. interesting ones that actually made life-or-death differences in the past.
Learning that someone is of European Ashkenazi descent lets us (probabilistically) predict a variety of genetic differences from the European average at each of many loci, and to very accurately predict, in the aggregate, a systematic skew across many loci to the Ashkenazim distribution.
This is just factually wrong. You can use many, many different traits, or just neutral variation to easily cluster humans in a high-dimensional space of genetic variance. The oceans, the Sahara desert, the steppes, and other geographical features were major factors in historical reproductive isolation, and the largest (and quite clear) clusters correspond pretty well to the old anthropological classifications. If you tell me some facts about bone structure, body fat ratio, malaria resistance genes, whatever, I can quickly assign high probability to a given mix of recent continental ancestry for an individual and make much better predictions about other traits using that info than I could without using that clustering. In the U.S., self-identified race is itself a very strong predictor of continental ancestry, and if one supplements with further questions about grandparents’ race or asks about multiracial ancestry it gets even better.
This post by physicist Steve Hsu discusses the topic well, also see this paper by Risch et al:
http://infoproc.blogspot.com/2007/01/metric-on-space-of-genomes-and.html
Yes, that’s what I meant—they’re an actually close-knit genetic group. “Negro” is not. “Black American” is a little closer, but not much (their African ancestors having been taken as slaves mostly from the west coast) - you’ll see obviously highly selected-for factors, like black skin and sickle-cell.
There are people who identify as black or who are identified as black under a “one drop” rule. This doesn’t seem as though it would give huge amounts of information about associated traits.
Aren’t clams that race is not genetic just plain silly?
Slightly but not just plain so.
For example, a lot of phenotypes would get classified as “black” in the American race structure, and “white, somewhat mixed” in the West European one. In the US, there’s a category called “Asian” with covers both East and South Asians. Two people in the US with the same ancestry and physical appearance may get classified as either white or Native American depending on their ties with a tribe. And so on.
Sure, “race” divides people according to physical appearance, ancestors, and culture, so it has a strong genetic component. But it’s not solely genetic, and inasmuch as it is, it’s still bad genetics, like the distinction between fish-and-dolphins and mammals is bad taxonomy.