I’ve noticed a lot of people in the HBD-o-sphere, including some very prominent bloggers, don’t know diddlysquat about statistics, so I am going to do a brief series on some basic concepts.
The first is my absolute favorite: The standard deviation represented by the Greek letter sigma, σ.
I remember learning about this in high school. I don’t know how I learned it, because God knows none of my teachers knew what a standard deviation is, but once I discovered it, I was so excited, because it’s one of the most fascinating concepts in the World.
Most of you know what a mean is. A mean, also known as an average, is simply the sum of a bunch of numbers, divided by the number of numbers.
So a sample of 40 Canadian adults (20 men and 20 women) had the following heights:
174,193,185,174,170,177,191,173,179,175,170,180,178,180,168,178,188,180,180,175
170,168,160,172,158,162,155,173,157,160,170,160,160,173,160,168,162,163,163,168
Now the mean height of these 40 Canadian adults is about 171 cm.
In order to determine the standard deviation, you take the square root of the average squared difference from the mean of the 40 heights. This number is sometimes adjusted for what’s known as degrees of freedom, but we wont discuss that now.
The standard deviation is an enormous amount of work to calculate by hand, so you use this excellent online calculator which shows the standard deviation is about 9.5.
Why should you care?
Because when the distribution of numbers is normal, the standard deviation has some fascinating properties. Roughly two thirds of the sample (68%) will fall within one standard deviation of the mean, so in our sample, two thirds should fall from 162 cm and 181 cm. In our sample it’s a little more (about 78%).
In a normal distribution, 95% should fall within two standard deviations of the mean, so in our sample, between 153 cm and 191 cm. In our sample, it’s a bit more than expected (98%). Our sample might not be perfectly normal because we combined men and women together.
In a perfectly normal curve, only 0.1% of values fall more than 3 standard deviations above the mean, and only 0.1% fall more than 3 standard deviations below the mean.
Who is the tallest Canadian?
There are about 27 million adults living in Canada. According to the Gaussian curve (commonly known as the bell curve), the highest value in a group of 27 million should be 5.4 standard deviations above the mean. Since Canadian adults average about 171 cm tall with a standard deviation of 9.5 cm, the tallest Canadian should be:
5.4(9.5) + 171 = 222 cm tall.
Or roughly, seven feet three inches.
The actual tallest Canadian was recently measured at seven feet six inches. So simply by taking the height of 40 random Canadian adults, we can predict the height of the tallest person in all of Canada within a few inches. That’s why standard deviation is such a brilliant concept.
Of course this only works on variables that are normally distributed, and only works because Canada’s tallest person is part of the biologically normal population. If I were to use this same technique to try to predict the tallest person in World history, I doubt it would work, because people like Robert Wadlow are such freaks of nature that they are outside biologically normal variation. They perhaps had mutations of large effects, which override normal polygenetic variation.
Pumpkin Person 
oh dear God.
Gott in Himmel!
what is a mathematical abstraction?
it’s nothing peepee or…
it describes the way the world is in a good enough way.
for example stock and bond total returns over days and weeks is modelled best by a t-distribution, over months by a normal dist.
neither dist is the actual dist, because there is no actual dist.
probability and statistics is just a means of quantifying human ignorance peepee.
peepee’s yet another example of the inability of HBDers to tell the difference between words, concepts, ideas, and things.
fuck einstein. he was a cunt.
read heisenberg!
heisenberg’s philosopphy of science is CORRECT.
Heisenberg was a Jew.
Heisenberg wasn’t jew
Ape
eat shit
Heisenberg wasnt jew, his theories were considered jewish by the nazis…
Eat shit
FUCK YOU MY MOMS DEAD
Dookie cried when he was owned by Pincher.
WHY IS THERE SO MUCH ANTISEMITISM ON THIS WEBSITE THE JEWS ARE A WONDERFUL PEOPLE
The Jews are a wonderful people but their great genius inspires jealousy. But what I find strange is that you only complain about anti-Jewish racism but I’ve never heard you complain about anti-black racism, even though you’re black yourself. Why does antisemitism bother you more than anti-black bigotry?
I’ve called out JS for mindlessly repeating “All blacks are evil”. I mostly ignore it because I hear people whining all day about anti-black racism even when it doesn’t exist.
I find antisemitism more disturbing because most hardcore anti-blacks (in my personal, real-life experience) are either prole whites or 1st generation immigrants, who are mostly powerless anyhow, but hardcore antisemitics tend to be pretty smart (they also seem to be deranged, more often than not).
Not that Jews really need help being defended, I just find antisemitic people to be distasteful.
All Whites are evil, which is a motto of many disenfranchised blacks. Furthermore, many powerless blacks also dislike immigrants. So it works both ways.
Many of the black commentators here, have yet to disprove HBD, as being non-applicable to the black race.
Afro-Sapiens said all races are created equal, and they were evolved only under different environments, which is exactly what HBD stands for!
Well, at least that’s one thing racist whites and blacks can agree: immigrants (most of them) suck.
“Afro-Sapiens said all races are created equal, and they were evolved only under different environments, which is exactly what HBD stands for!”
Again, I said races were invented by society whereas phenotypes we call races evolved under different environments and that there is no evidence that these phenotypes include an intellectual or behavioral component. That’s absolutely not what HBD stands for.
Can you please repeat what is the IQ you claim to have ?
I don’t know what my IQ is. My SAT score corresponds to an IQ score of 120 and change.
Given the fact that most, if not all, regions of Sub-Sahara Africa, have yet to evolved on a progressive level independently, similar to that of Europe and Asia, one can make an inference, that those with the “phenotypes” from that region, are inherently less intelligent and incapable of civilizational attainment. HBD would then further explain, that blacks or the individuals with those corresponding “phenotypes”, evolved from an environment that doesn’t not require high intelligence, hence is what you find in Sub-Sahara Africa. Native inhabitants from that region have the lowest IQ scores in the world, due to an abundant resources and warm weather, which did not require humans to think cognitively deeper or with more sophistication, for survival purposes.
NABALT
Didn’t see you answered.
The Philippines, the Malay archipelago, the Pacific, Siberia, Australia, Central Asia, the Americas out of the Andes and Mesoamerica are some regions that have no more indigenous civilizational development than Subsaharan Africa.
Only Mesoamerica and the Andes developed fully independent civilization though with many lacking elements. Eurasia and North Africa have benefited technological and cultural exchange with the Middle East, India, China and Mediterranean and later Western Europe as the main sources of innovation.
West Africa developed an Iron Age civilization with indigenous elements and through contact with the islamic world, the Horn Africa has the same profile whereas Nubia is fully a part of the Nile Valey Civilization.
Then Africa developed a civilization that corresponds to her environment but not in the way HBD thinks. Tropical climates are actually the toughest, and Africa, like all tough climate areas always had and still has low population density because it is simply not as suited for human life as temperate Europe and East Asia. Pre-colonial Brazil, which mirrors Subsaharan Africa in its climate and geography even had less civilization than the latter.
The black races (including blacks who left Africa like Australian aboriginals) are the only races to never develop or invent anything anywhere in the World. They are way behind the rest of humanity. Had sub-Saharahan Africa not been colonized by outsiders, it would still be 100% in the Stone Age. Actually a bit behind the Stone Age
For this reason I believe there are only 2 races: blacks and non-blacks.
https://en.wikipedia.org/wiki/Iron_metallurgy_in_Africa
So let me correct: You know nothing of what Africa invented and for that reason, you believe that there are only 2 races, blacks and non blacks. Hence, the issue is you being an ignorant, not Africans being sub-humans.
Afrosapiens (your name is a contradiction), the iron technology was taught to black Africans by caucasoids from the Middle East who enslaved blacks long before Europeans did. Notice how blacks always ended up slaves whenever they encountered a non-black group.
No black race has ever invented anything on their own & I get very angry when blacks claim to have invented stuff (except for nonsense like various music forms, rock, pop, jazz etc; I’ll give you that)
Humans were more or less still monkeys until we left Africa and other tropical regions. Only then did we evolve the capacity to leave the Stone Age.
So only two races: blacks and non-blacks
lol, first thing, Muslims enslaved every kind of non-muslims, Southern Europe was victim to muslims slave raiders as much as West Africa, the only difference is that Europeans did not sell slaves.
Second thing, there are very few things before contemporary era that any “population” can claim to have invented from the beginning. Africa invented her agriculture, her metal working technology and it puts it at the iron age level of civilization, there is no proof that those developments came from anywhere else, whether you like it or not.
Humans were evolved into modern humans long before they left Africa. However, many archaic hominids lived out of Africa before homo sapiens.
Bottom line: you’re an ignorant and I’m glad you’re here harming Pumpkin person’s blog already tiny credibility.
So only two races: blacks and non-blacks
A lot people make that claim, but there’s plenty of places that were hardly more advanced than Sub-Saharan African before modern times (and no, I’m not just talking about Papua New Guinea/Australia). And even among the more advanced races, there’s significant variation (did eastern Europe ever come even close to the accomplishments of the West?)
Afrosapiens how educated are you? Didn’t you learn basic world history in school? Africa is not one of the five places where agriculture independently emerged:
https://books.google.ca/books?id=zeWxAAAAQBAJ&pg=PA35&lpg=PA35&dq=agriculture+emerged+independently+china+middle+east&source=bl&ots=4WLLdvsFjp&sig=mO6dnlKch_C6ZN7LJsRGDv8QZfs&hl=en&sa=X&ved=0CDAQ6AEwB2oVChMIvpfez-qayAIVkoCSCh38Cgud#v=onepage&q=agriculture%20emerged%20independently%20china%20middle%20east&f=false
Iron technology did not independently emerge there either
West Africa invented agriculture independently, hadn’t it be the case, it would have developed non-indigenous crops like middle eastern wheat but it instead developed rice, cowpeas, millet and sorghum around -5000 BC, when no civilization existed in Eurasia.
If HBD is right thinking Africa has the most hospitable environment on the planet, then why is its population density so low although Rushton claims that blacks evolved to multiply at a faster rate than other races ?
Another question is why did Eurasian races that are pretended to have evolved into intelactually superior beings had to wait until the late 19th century to colonize scarcely populated Africa (the most hospitable part of the world as you say) although they knew of its existence for thousands of years ?
Doesn’t it make sense that Eurasia became what it became because it has the environment to sustain high population density whereas Africa could not afford that luxury ? Did it ever cross your mind that different levels of civilizational advancement were not due to the quality of one region’s human capital but simply due to its quantity ?
Afrosapiens, scholars in the field clearly disagree with you. Africa was not one of the locations where agriculture independently emerged according to even liberal academics.
Africa has a low population density because even with the benefits of hospitable environment and high reproductive output, Africans lacks the survival skills to achieve a dense population
David are you Letterbox ?
Just a couple google searches reveal that independent development of agriculture in Africa is actually consensus among specialists.
https://www.google.fr/webhp?sourceid=chrome-instant&ion=1&espv=2&ie=UTF-8#q=invention%20of%20agriculture%20in%20africa
https://www.google.fr/webhp?sourceid=chrome-instant&ion=1&espv=2&ie=UTF-8#q=origins+of+agriculture+in+africa
“Africa has a low population density because even with the benefits of hospitable environment and high reproductive output, Africans lacks the survival skills to achieve a dense population”
What do you call hospitable environment ?
-Endemic malaria and tse-tse fly ?
-Constant extreme warmth ?
-6 month of intense drought then 6 month of extreme moisture ?
-Low productivity oxidated soils ?
And why couldn’t superior Eurasians get better survival skills to thrive in Africa during the thousands of years they knew of its existence ? Why isn’t Nigeria a 1 billion inhabitants caucasoid majority country now, since the inferior blacks, incapable to survive in the environment they were evolved for had to be taken over by races selected for higher intelligence in any environment ?
And why couldn’t superior Eurasians get better survival skills to thrive in Africa during the thousands of years they knew of its existence ? Why isn’t Nigeria a 1 billion inhabitants caucasoid majority country now, since the inferior blacks, incapable to survive in the environment they were evolved for had to be taken over by races selected for higher intelligence in any environment ?
One could answers that they beneficiate european technology…
But even with their technology, Europeans only managed to minimally settle the most temperate parts of Africa whereas the Arabs never made significant conquests and settlements, the Chinese came and left straight away. What I mean to say is that the USA or any European immigrant nation could never have been replicated anywhere in Africa and ironically, Native Americans did nothing remarkable on the territory of the country that would later become the world’s only superpower.
Why Europeans would settle a place with a climate they arent used to ? Exploited it and see their population grow and their quality of life increase thanks to the earnings of this exploitation is a much more smarter choice and this is what they did.
“Why Europeans would settle a place with a climate they arent used to ?”
Europeans settled Australia, North and South America, the Southern tip of Africa, all places with a very different climate from that of western Europe but they could not do it in most of Subsaharan Africa even though they wanted it very bad, tropical Africa was just too inhospitable.
Europeans didn’t see their population grow thanks to the exploitation of Africa, Asia or even the Americas. Africa was under effective colonial rule for no more than 60 years, the colonies of Africa gave very little return on investment and massive settlement of Europeans there was not even thinkable, the environment is too tough, almost in the same magnitude as the arctic.
Europeans settled Australia, North and South America, the Southern tip of Africa, all places with a very different climate from that of western Europe but they could not do it in most of Subsaharan Africa even though they wanted it very bad, tropical Africa was just too inhospitable.
I was wainting for this one….Europeans settled the littoral (especially the more tempered southern littoral) of Australia, North America and the tempered parts (i.e. Argentina) of South America, guess why ? The most tropical places of America were also settled by Europeans, but the high proportion of mixed race population in those areas indicate that Europeans werent as numerous than in more tempered areas, another time, guess why ?
Europeans there was not even thinkable, the environment is too tough, almost in the same magnitude as the arctic.
So your main argument against HBD is the toughness of the environment of Africa ?
“So your main argument against HBD is the toughness of the environment of Africa ?”
My main argument against HBD is that it is all unsubstantiated speculation, from the unfindable genetic cause of the biologic differences in intelligence they claim to the evolutionary pressures that according to HBDers selected Eurasians for higher intelligence because they had to face the ice age and then have enjoyed favorable temperate climates whereas Africans are said to have always benefited an hospitable environment that made survival effortless when the reality is the opposite, tropical Africa is hostile to human life.
It is more complex than that. It is not simply about the harshness of the environment. It is about the cognitive demand of the environment.
The only civilizations to have independently emerged in the tropics are the Incas and Mesoamerica and they only owe it to the fact that their climates were not tropical, the Aztec and the Incas flourished on temperate Altiplanos whereas the Mayas reached high population density on a narrow coastal plain benefiting from cooling maritime influences and high availability and accessibility of underground water. Anywhere else in America, nothing significant happen. Yet it is the same race everywhere.
But there is another parameter that must be taken into account. Civilization is not an end but a means, a means to manage high population density, allocate resources and make use of the human capital. So civilization could not appear in areas where population density was difficult to increase and that’s not just a matter of climate, terrain also plays a role. Huge flat continental masses of North and South America (but also Subsaharan Africa, Australia, Siberia and Central Asia) are the opposite of what favors high concentrations of population. On the opposite, Peninsulas like Italy, Korea or Greece, valleys like the Nile, Mesopotamia, the Ganges, the Indus or tiny volcanic islands like Honshu and Java are places where agriculturalists effortlessly reproduce and create the conditions that lead to civilization.
“It is not simply about the harshness of the environment. It is about the cognitive demand of the environment.”
Then what’s more cognitively demanding in an hospitable temperate environment than in an hostile tropical one ?
https://en.wikipedia.org/wiki/List_of_countries_by_population_in_1900
This is the list of countries by population in 1900. It’s interesting in the sense that it shows which countries had the most numerous human capital at the dawn of the modern world and as the result of their pre-modern history eventhough the West and Japan already had made huge steps into industrialization and mechanization.
I think the standard argument for climate differences causing IQ differences is that the harsh African environment was more random and could not be planned for, making a high IQ less useful. The proliferation of diseases or famine cannot be predicted or perhaps even defended against even if one knew it was coming. However, in more temperate climate the change of seasons could easily be planned for if one had an high enough IQ, and surely enough, high IQ evolved.
The proliferation of diseases or famine cannot be predicted or perhaps even defended against even if one knew it was coming. However, in more temperate climate the change of seasons could easily be planned for if one had an high enough IQ, and surely enough, high IQ evolved.
Correct. IQ is pretty useless in defending against random tropical diseases, unless you have an IQ of 180 & can figure out a cure.
But IQ is very useful in cold climates for figuring how to make fire, shelter, warm clothing, and hunting.
“But IQ is very useful in cold climates for figuring how to make fire, shelter, warm clothing, and hunting.”
Fire is an invention of homo erectus, it is useful yearlong in any climate for cooking, lighting, clearing forests and driving back animals, from mosquitoes to big cats. There is no way Eurasian homo sapiens evolved to make fire more than African homo sapiens or homo erectus.
Shelter is crucial in the tropics to protect people from animals, thunderstorms (which in the tropics are of an intensity that you can’t even figure out if you never went there), and heavy rainfall in the rain season. On an old flat land mass like Africa, building shelter was even more important since caves barely exist like in Eurasia. Anyway, building shelter only requires the IQ of children building a house in the trees.
Getting warm clothing only requires the intelligence to take the fur of the animals you hunt, getting cooling clothing like African textile is something that requires more ingenuity. But in any case, making textile only requires the IQ of a seamstress.
Hunting is crucial in Africa and animals there are much less easy to hunt, they have evolved next to hominids for millions of years and have learnt to fear them. Moreover, endemic tse-tse flies limited the ability of Africans to keep large domestic animals, that’s why they relied on hunting to get meat other than poultry even after they developed agriculture. Anyway, hunting requires nothing more than a hunter-gatherer IQ or the intellectual level of earlier hominids who were hunters too.
Then predicting the change of seasons is crucial in the tropics too, the wet season is extremely wet whereas the dry season is extremely dry. both last 6 months and bring challenges that have to be predicted and anticipated for a longer period of time than the 4 month long mild winter of western Europe. I hope you realize that winter in Europe is nothing like winter in North America and that it never comes close to arctic-like in terms of weather.
Afrosapians,
Your claims have already been debunked by Lynn way back in his 2006 book “Race Differences in Intelligence: An evolutionary perspective”
During the last 200,000 years the ancestors of the Africans continued to inhabit the tropical and sub-tropical environments of equatorial sub-Saharan Africa. This environment was not strongly cognitively demanding for them because primates had become adapted to it for some 60 million years. During the evolution of the hominids Homo erectus were largely plant eaters but supplemented their diets with scavenging the carcasses of animals killed by lions, leopards, and cheetahs (Lee, 1968; Tooby and de Vore, 1989). The evolving Africans lived much as hunter-gatherer peoples in tropical and sub-tropical environments do today, subsisting largely on plant foods, of which numerous species are available throughout the year, and on
insects and eggs, with only occasional supplementation from animal meats obtained from hunting.
The ready availability of plant foods, insects, and eggs throughout the year meant that the evolving African peoples in tropical and sub-tropical Africa did not have to hunt animals to obtain meat. A conference of anthropologists was convened in 1966 to debate the Man the Hunter thesis of the importance of hunting for contemporary hunter-gatherers, at which “the consensus of opinion was that meat is of relatively little nutritional importance in the diets of modern tropical foragers” (Stanford and Bunn, 2001, p. 4). In 1999 a similar conference took place at which there was “a consensus that hominid diets were primarily plant based, as they are among modern tropical foragers” (Stanford and Bunn, 2001, p. 356). Hence the Africans
had no need to develop the intelligence, skills, tools, and weapons needed for hunting large mammals.
Furthermore, the temperature of equatorial Africa varies annually between approximately 32°C. in the hottest month and 17°C. in the coldest, so the African peoples did not encounter the cognitively demanding requirements of having to make needles and thread for making clothes and tents, to make fires and keep them alight, or to prepare and store food for future consumption. It was relatively easy to keep babies, infants, and young children alive because there was no need to provide them with clothing and from quite a young age they were capable of going out and foraging for food by themselves.
Nevertheless, the brain size of the Africans increased during the last 200,000 or so years from approximately 1,186 to l,276cc, and it can be reasonably assumed that this entailed an increase in their intelligence to its contemporary value of 67. This increase occurred because of continual directional selection for intelligence, i.e., the more intelligent individuals had more surviving offspring. The genetical processes will have consisted of the increase in the frequencies of the alleles for higher IQs and probably of some mutations for higher intelligence.
If these mutations for higher intelligence appeared they would have spread through the population because high intelligence is a fitness characteristic but they would not have spread so rapidly and extensively as in the races in temperate and cold climates because the selection pressures for higher intelligence were not so strong in the benign climate of equatorial Africa.
The level of intelligence that evolved in the Africans was sufficient for them to make a little progress in the transition from hunter-gathering to settled agriculture, but not sufficient to develop anything that could be called a civilization with a written language and arithmetic, construction of a calendar, cities with substantial stone buildings, and other criteria set out by Baker (1974).
Click to access lynn-race-differences-in-intelligence.pdf
“Your claims have already been debunked by Lynn way back in his 2006 book “Race Differences in Intelligence: An evolutionary perspective””
Lynn would be better at debunking scientific reality if he was a specialist in the fields he discusses, for now he’s just ridiculing himself and makes those who drink his kool aid look even dumber.
“This environment was not strongly cognitively demanding for them because primates had become adapted to it for some 60 million years.”
They actually developed their intelligence because that environment was cognitively demanding whereas no species of any sort evolved only 1% of that intelligence in temperate or polar regions.
“The evolving Africans lived much as hunter-gatherer peoples in tropical and sub-tropical environments do today, subsisting largely on plant foods, of which numerous species are available throughout the year, and on
insects and eggs, with only occasional supplementation from animal meats obtained from hunting.”
How did non-tropical hunter-gatherer populations subsist ?
https://www.google.fr/url?sa=t&rct=j&q=&esrc=s&source=web&cd=2&cad=rja&uact=8&ved=0CCcQFjABahUKEwiV1brO4Z_IAhVFQhQKHcFkCaQ&url=https%3A%2F%2Fwww.humanities.uci.edu%2Fhistory%2Fucihp%2Fresources%2F6th%2520grade%2520curriculum%2FEarly%2520Human%2520Communities%2520-%25206.1%2520(1-2)%2FStone%2520Age%2520diet.doc&usg=AFQjCNGM4ax1toS4APYi3_i6yq_0Fu97eQ&sig2=mSJREcTQTd7admmVxq6fnQ
https://en.wikipedia.org/wiki/Paleolithic_diet
https://en.wikipedia.org/wiki/Inuit_diet#Food_sources
In any case, there is no sign of any kind of genetic evolution toward intelligence for hunting, if something like that happened, the only outcome would have been more warlike and athletic populations, but HBD rather thinks that these are attributes of the black race more than any other one.
“had no need to develop the intelligence, skills, tools, and weapons needed for hunting large mammals.”
Yet they did develop these skills, tools and weapons needed for hunting large animals and they did it even before humans left Africa.
https://www.google.fr/search?q=bushmen+hunting&espv=2&biw=1280&bih=699&source=lnms&tbm=isch&sa=X&ved=0CAYQ_AUoAWoVChMIxPqP0uWfyAIVw0gUCh1fzg6P
https://www.google.fr/search?q=bushmen+hunting&espv=2&biw=1280&bih=699&tbm=vid&source=lnms&sa=X&ved=0CAgQ_AUoAmoVChMIqK7r3OWfyAIVBT0UCh3yvA8R&dpr=1
“Furthermore, the temperature of equatorial Africa varies annually between approximately 32°C. in the hottest month and 17°C.”
Lol, two mistakes here:
1- It is very exceptional that temperatures go as low as 17°C in tropical Africa. Some friends of mine in Cameroon told me they experienced a 18°C week only once in their lifetime and it felt freaking cold for them, people were wearing multiple layers of cloth or European autumn cloth although humidity (over 90%) gave an actual temperature closer to 25°.
2- Humidity is very high in Africa, for instance today in Lagos temperature is 25°C but humidity is 94% and it feels like 36°C, and this is a cold day. When you have a typical temperature of 30°C, it always feels like more than 45°, the air is burning, thick and heavy and any move feels like a marathon. Africa is not warm as an Italian summer, it is warm as an oven and it seems like you can’t really realize how it feels until you come there.
By the way, if you want to get familiar with converting thermometer temperature to felt temperature with humidity, just search humidex.
“so the African peoples did not encounter the cognitively demanding requirements of having to make needles and thread for making clothes and tents, to make fires and keep them alight, or to prepare and store food for future consumption. It was relatively easy to keep babies, infants, and young children alive because there was no need to provide them with clothing and from quite a young age they were capable of going out and foraging for food by themselves.”
Laughable, first because they learned to make all that stuff on their own without any Eurasian to teach them, so let’s say they made it just for fun.
Does Lynn think that heating is the only purpose of making fire ? And does he think that mastering fire requires surgeon intelligence ?
Wow, if it’s easy to keep babies alive in Africa, just tell me why is infant mortality so high ? Why did they need to develop some kind of genetic resistance to malaria in order not to die too soon ?
And what do you call a young age for foraging ? You know, African hunter-gatherers die young, life expectancy is low among them yet we never see toddlers hunting in their communities.
“Nevertheless, the brain size of the Africans increased during the last 200,000 or so years from approximately 1,186 to l,276cc, and it can be reasonably assumed that this entailed an increase in their intelligence to its contemporary value of 67.”
Quoting wikipedia:
A number of studies have found correlation between variation in brain size in cranial capacity and geographic ancestry in humans.[10][11] This variation in cranial capacity is believed to be primarily caused by climatic adaptation that favor large round heads in colder climates because they conserve heat and slender heads in warm climates closer to the equator (See Bergmann’s rule and Allen’s rule).[12]
The largest study done on the subject of geographic variation in brain size is the 1984 study Brain Size, Cranial Morphology, Climate, and Time Machines. The study found that human brain size varied with latitude of biogeographic ancestry.[10] The relationship between latitude and cranial size is described in the study as an example of Bergmann’s principle that crania are more spherical in cold climates because mass increases relative to surface area to conserve core temperatures and behaves independently of “race”.
__________________
In the course of evolution of the Homininae, the human brain has grown in volume from about 600 cm3 in Homo habilis to about 1500 cm3 in Homo sapiens neanderthalensis. Subsequently, there has been a shrinking over the past 28,000 years. The male brain has decreased from 1,500 cm3 to 1,350 cm3 while the female brain has shrunk by the same relative proportion.[45] For comparison, Homo erectus, a relative of humans, had a brain size of 1,100 cm3. However, the little Homo floresiensis, with a brain size of 380 cm3, a third of that of their proposed ancestor H. erectus, used fire, hunted, and made stone tools at least as sophisticated as those of H. erectus.[46] In spite of significant changes in social capacity, there has been very little change in brain size from Neanderthals to the present day.[47] “As large as you need and as small as you can” has been said to summarize the opposite evolutionary constraints on human brain size.[48][49] Changes in the size of the human brain during evolution have been reflected in changes in the ASPM and microcephalin genes.[50]
“The genetical processes will have consisted of the increase in the frequencies of the alleles for higher IQs and probably of some mutations for higher intelligence.”
List these alleles please. You know, genetics is not magic, a selective sweep is something obvious and easily identifiable, it’s nothing like the millions of small effect SNPs that could only be found if we sample millions of individuals as HBDers like to say.
“The level of intelligence that evolved in the Africans was sufficient for them to make a little progress in the transition from hunter-gathering to settled agriculture, but not sufficient to develop anything that could be called a civilization with a written language and arithmetic, construction of a calendar, cities with substantial stone buildings, and other criteria set out by Baker (1974).”
Africans developed agriculture because their population exceeded what their environment could sustain with an hunter-gatherer lifestyle. However, their environment was not the best to allow high yield agriculture that produces surpluses, and hence gives the ability to increase population density and then significant urban development. In addition to that, endemic malaria was another impediment because the best way to prevent it is to avoid human concentration. Moreover, the slave trade played its role in depopulating the continent. For all those reasons, at the dawn of our modern world, planet earth was settled like that:
And if you only take the old world into account, you see a perfect correlation between population density and civilizational development.
And just for your information: the Sahel has had a literate civilization for more than 1000 years, Africans seldom build with stones because stone simply does not exist in most parts of Africa whereas laterite is found everywhere, it is solid and it keeps indoors spaces cool. However where stone exists, like in the Drakensberg or in the Zimbabwean plateau, it is used.
A few West African calendars:
https://en.wikipedia.org/wiki/Yoruba_calendar
https://en.wikipedia.org/wiki/Akan_calendar
https://en.wikipedia.org/wiki/Igbo_calendar
Pumpkin, it’s time you realize that the true problem here is that you’re a complete ignorant who should not believe that only what he knows does exist.
Find some more about hunting here:
https://en.wikipedia.org/wiki/Hunting_hypothesis
“As societal evidence Buss (2011) cites that modern tribal societies use hunting as their primary means of acquiring food. The Aka pygmies in the Central African Republic spend 56% of their quest for nourishment hunting, 27% gathering, and 17% processing food. Additionally, the !Kung in Botswana retain 40% of their calories from hunting and this percentage varies from 20% to 90% depending on the season.[1] For physical evidence Buss first looks to the guts of humans and apes. The human gut consists mainly of the small intestines, which are responsible for the rapid breakdown of proteins and absorption of nutrients. The ape’s gut is primarily colon, which indicates a vegetarian diet. This structural difference supports the hunting hypothesis in being an evolutionary branching point between modern humans and modern primates. Buss also cites human teeth in that fossilized human teeth have a thin enamel coating with very little heavy wear and tear that would result from a plant diet. The absence of thick enamel also indicates that historically humans have maintained a meat-heavy diet.[1] Further, Buss looks to Vitamins A and B12, which the body is unable to produce, but are found in meat. The absence of these vitamins in the human body also implies a human dependence upon meat to obtain such vitamins.[1] Finally, Buss notes that the bones of animals human ancestors killed found at Olduvai Gorge have cut marks at strategic points on the bones that indicate tool usage and provide evidence for ancestral butchers.[1]”
Afrosapiens, no one disputes that Africans eat meat and have some impressive hunting skills, but they were nowhere near as dependent on complex hunting skills as non-Africans were. More from Lynn’s 2006 book:
Survival during the ice ages for the peoples in the cold temperate environments in North Africa and South Asia, and later in the sub-arctic environment of Europe and northern Asia, would have presented a number of cognitively demanding problems that would have acted as selection pressures for greater intelligence than was required in the tropical and sub-tropical climates of sub-Saharan Africa.
There would have been five major problems. Eirst: plant foods were not available during the winter and spring, and were not abundant even in the summer and autumn; insects and reptiles were not available either, because these hibernate in temperate climates. The major source of food, therefore, became large mammals such as antelope, deer, horses, and boars that people had to hunt to secure food supplies. It would have been difficult to hunt these large mammals in the grasslands that covered much of the northern hemisphere during the last ice age because there is good visibility for several thousand yards and the herbivores have ample warning of approaching predators. Hunting in open grasslands is more difficult than in the woodlands of the tropics and sub-tropics, where there is plenty of cover for hunters to hide in.
The humans that evolved in equatorial Africa were largely herbivorous and were not adapted for hunting large mammals, so this would have presented new cognitive problems for them. Large herbivores can run fast and are virtually impossible to catch simply by chasing after them. The only way of killing these animals was to
make use of natural traps into which the animals could be driven and then killed. One of the most frequently exploited natural traps was narrow ravines through which the beasts could be driven and where some of them would stumble and could be speared or clubbed by members of the group waiting in ambush.
Another was cliffs towards which a group of men could drive a herd of herbivores, so that some of them would fall over the edge and be killed or sufficiently injured for other members of the hunting group to kill them. Other natural traps were bogs and the loops of rivers, into which hunting groups could drive herbivores and then kill them. Archeological excavations have shown that all these traps were used by early humans in Eurasia (Geist, 1978; Mellars, 1999). Working out strategies for cooperative group hunting and trapping large herbivores in these ways would have required an increase in cognitive ability.
It has been shown that among contemporary hunter-gatherers the proportions of foods obtained by hunting and by gathering varies according to latitude. Peoples in tropical and subtropical latitudes are largely gatherers, while peoples in temperate environments rely more on hunting, and peoples in arctic and sub-arctic environments rely almost exclusively on hunting and fishing, and have to do so because plant foods are unavailable except for berries and nuts in the summer and autumn (Lee, 1968).
When people migrated into the temperate regions of North Africa and South Asia, many of those with low IQs could not survive the cold winters and this raised the IQ of the survivors to 84.
Second: the effective hunting of large herbivores required the manufacture of a variety of tools from stone, wood, and bone for making spears and for cutting up the carcasses. Some of these animals could be brought down by spears that had to be made by hafting or tying a sharp piece of stone, which had to be manufactured, onto the end of a shaft. When these peoples had brought down and killed a large herbivore they would have had to skin it and cut it up into pieces of a size that could be carried back to the base camp for the women and children.
These animals have thick skins and tough ligaments that are difficult to cut, and people would have needed sharp tools manufactured for these specific purposes. In sub-arctic environments animals that are killed freeze fairly rapidly and become impossible to cut up, so the hunters had to have good cutting tools that would do the job quickly, before the carcasses froze solid.
Peoples in cold environments need more tools of different kinds and greater complexity than peoples in tropical and sub-tropical environments. This has been shown by Torrence (1983), who has demonstrated an association between latitude and the number and complexity of tools used by contemporary hunter-gatherers. He found that hunter-gatherer peoples in tropical and subtropical latitudes such as the Amazon basin and New Guinea typically have between 10 and 20 different tools, whereas those in the colder northern latitudes of Siberia, Alaska, and Greenland have between 25 and 60 different tools.
In addition, peoples in cold northern environments make more complex tools, involving the assembly of components, such as hafting a sharp piece of stone or bone onto the end of a spear and fixing a stone axe head onto a timber shaft.
Third: another set of problems encountered by the peoples in the northern hemisphere would have been concerned with keeping warm. People had to solve the problems of making tires and shelters. Archeological excavations have shown that during the ice ages peoples in China and Europe were making fires. To do this they would have had to learn how to make sparks by striking one stone against another and then get these sparks to ignite dried grass. They would have needed a supply of dry grass and dry wood and animal dung stored in caves to get their fires started and keep them going. This would have needed intelligence and forward planning.
Peoples in sub-Saharan Africa and Australia also had fire but it would have been easier to get fires going in the tropics and sub-tropics because there would have been spontaneous bush fires from which ignited branches could be taken and carried back to camp to start domestic fires. The problems of starting fires and keeping them burning would have been considerably more difficult in Eurasia and North America than in the tropical and sub-tropical southern hemisphere.
Fourth: a further problem of keeping warm would have necessitated the making of clothing and tents by sewing together animal skins. This entailed the drying and treatment of the skins of large herbivores and the manufacture of needles from bone and thread to sew skins together to make clothes and footwear. It would have been necessary to make clothes for babies and children as well as adults. Some people kept warm by living in caves but in places where there were no caves they used large bones and skins sewn together to make tents resembling the yurts that are still made in Mongolia (Geist, 1978; Mellars et al., 1999).
Fifth: the final problem for the peoples in temperate and cold environments concerned food storage. This was necessary because when they had killed and dismembered several large mammals they could not eat them all within a few days and they therefore needed to conserve them for future use. Some animals that could be killed are migratory and appear in any particular location for only short periods of time each year. This presents opportunities to kill large numbers of them, too many for immediate consumption, but they can be stored for future use.
One example is reindeer that migrate regularly over long distances at certain times of the year. In many cases they follow the same routes at the same time of year, so their appearance could be predicted by early humans who had acquired a knowledge of the seasons and the calendar from astronomical observations. Another migratory species is salmon, who migrate in large numbers at a certain time of the year from the sea up rivers in order to spawn. Many of these rivers are quite shallow and it is not too difficult to spear large numbers of salmon as they swim upstream. It is also possible to catch them in nets, the construction of which was another cognitively
demanding problem for peoples in Eurasia. These peoples would have been able to anticipate the arrival of these migrating herds and fish and kill large numbers of them as they passed through.
In very cold environments the problem of storing food for future consumption could be solved for part of the year by building icehouses, which served as freezers for preserving the carcasses. Another solution was to cut the flesh into thin slices and dry them. If this is done properly the pieces will remain edible for a considerable time, but if not they become toxic. Some of the less intelligent, unable to do this properly, would have died from food poisoning. This would have been another of the many selection pressures acting to increase the intelligence of the peoples colonizing the niche of the temperate and cold environments.
It has been suggested by Miller (1991) that the storage of food would also have required the formulation of rules for rationing its consumption and that this would have involved the development of arithmetic to allocate it equitably. Among contemporary hunter-gatherers it has been shown by Binford (1980, 1985) that there is a relationship between the extent to which they store food and the temperature of the environments in which they live. The colder the environments, the more they store food for future consumption. He reports that in general it is only in colder climates where growing seasons are less than about 200 days that hunter-gatherer peoples store food.
In addition to these five cognitive problems of survival in the northern hemisphere, a further selection pressure for greater intelligence on these peoples would have been the operation of sexual selection by women. In Eurasia and North America women would have become entirely dependent on men for much of the year to provide food for themselves and their children.
In equatorial Africa and the southern hemisphere where plant and insect foods are available throughout the year, women are relatively independent of men. Even women with infants and young dependent children can take these with them on foraging trips, or can leave them in the care of other women for a few hours while they go out and gather plant foods. It would have been more difficult and frequently impossible for women with infants and young children in the northern hemisphere to go out on hunting expeditions, possibly lasting several days, kill and dismember large mammals, and carry pieces of them for many miles back to camps.
The effect of this would have been that women in the northern hemisphere would have depended on men to bring them food. They would therefore have tended to accept as mates intelligent men who were good at hunting and making tools and weapons. The effect of this sexual selection by women would have been that intelligent men would have had more children and this would have increased the intelligence of the group.
Another effect of the greater dependence of women on men in Eurasia would have been that men and women would become psychologically more closely bonded. This explains why the marriages and non-marital relationships of European and East Asian peoples are more stable than those of Africans (Lynn, 2002).
Survival in the cold environment of the northern hemisphere would have required an increase in general intelligence, defined as general problem solving and learning ability, and in most of the primary cognitive abilities of which general intelligence is composed. Stronger reasoning ability would have been needed to solve all the new problems encountered in the cold northern latitudes such as building shelters and fires, making clothes, and manufacturing more efficient tools for killing, butchering, and skinning large animals.
Improved verbal ability would have been needed for better communication in discussions of how to solve these problems, for planning future activities, and for transmitting acquired cultural knowledge and skills to children.
Improved visualization ability would have been needed for planning and executing group hunting strategies, for accurate aiming of spears and missiles, and for the manufacture of more sophisticated tools and weapons from stone, bone, and wood. Fathers would have shown sons how to chip flints to produce good cutting tools and to make spears with sharp points, and these skills would have been conveyed largely by watching and imitation, much as craft skills are learned today by apprentices watching skilled craftsmen, rather than by verbal explanations. Hunting and tool making would have been undertaken principally by males and this would be why it has virtually always been found that the visualization abilities are stronger in males than in females (Linn and Peterson, 1986).
There would have been less selection pressure on the peoples in the northern hemisphere to develop better short-term memory and perceptual speed, which explains why these abilities have not become so strongly enhanced among the Europeans as compared with the Africans.
Click to access lynn-race-differences-in-intelligence.pdf
Hey Afrosapiens
If you want to understand the connection between latitude and IQ read this:
https://jaymans.wordpress.com/2012/01/17/iq-ceilings/
Do an article on r vs. r-squared
I really like this article here by Dr. Steve Hsu.
http://infoproc.blogspot.com/2014/02/correlation-and-variance.html
Yes, he does a good job covering it. I was going to do my own article about it, like you asked, but it would be a huge amount of work to do it right, so for now I might just link to this great article by Hsu that you found
Pingback: The IQ distribution of Pumpkin Person readers | Pumpkin Person
Pingback: linkfest – 09/28/15 | hbd chick
OMG congrats, the great and wonderful HBD Chick linked to you!
Thank you so much! I am extremely honored to finally make one of HBD chick’s legendary linkfests !
>Most of you know what a mean is. A mean, also known as an average, is simply the sum of a bunch of numbers, divided by the number of numbers.
It’s more complicated. The mean/average you are talking about is called the arithmetic mean, but there are several others. They are all measures of central tendency. https://en.wikipedia.org/wiki/Central_tendency
For instance, the geometric mean is used to calculate the HDI scores. Medians are used to remove effects of outliers.
The same is true for the standard deviation (SD), it is just one of several possible measures of dispersion. It’s not very intuitive. The most intuitive measure is the mean absolute deviation (MAD), which is the average distance to the mean. The SD and MAD give slightly different values.
Pingback: What is a Z score? A definition | Pumpkin Person
Pingback: Estimating the IQ of Vladimir Putin | Pumpkin Person