Here is how to understand human evolution (if you don’t know already) Many followers do.
0) Vision increases your range of awareness of threat AND opportunity.
1) Access to standing and running gets you greater defense and greater range, and greater access to foods.
2) Access to better foods lets you swap brain size for digestion size.
3) Better food, smaller digestion and bigger brains, lets you narrow pelvis and run longer and faster at lower energy cost.
4) Walking and Running are ‘cheap’ and free up your hands to carry tools, weapons, and resources increasing your range, safety, and food opportunity.
5) Losing your fur lets you dissipate heat faster, so that you can run down rather than fight increasingly rewarding game.
6) Having achieved physical imitations, Increasing your cognitive metabolism is all that can improve from there. The physical evolution of (skeletal) modern humans doesn’t appear in skeletal remains.
7) METABOLISM depends a great deal on heat dissipation, and climate affects heat dissipation, as such IQ differences generally reflect ancestral cognitive metabolism in increasingly cold vs increasingly hot temperatures.
8) Since we’re cooperative creatures, and cooperation is an unsubstitutable good, the only improvement you can make after cognitive metabolic improvement is decreasing in friction (increase in efficiency) meaning selective reproduction for ability and selective culling of lacking ability)
10). Communication distributes computation decreasing demand for memory retention and increasing demand for adaptation.
11). The only way to improve communication is a system of measurement.
12) the only way to improve a system of measurement is parsimony, consistency, correspondence, and coherence. Ie: “P”.
All of those show up in the archeological record in skeletal remains. But that doesn’t explain the difference between the three waves out of Africa, or Africa itself.
What doesn’t show up on the record?
Great apes have an average IQ of 25, and corresponds to a 2.5 year old european – although visual memory in apes and social cognition in humans excel in opposite directions. Humans at this level have an extreme intellectual disability and are unable to self-care.
The average IQ of bushmen is estimated at 55, and corresponds to the mental age of a European of about 8 years. The average cranial capacity of Bushmen is 1250 cubic centimeters. This is at the bottom end of mild intellectual disability. These people can self-care and learn very basic skills.
The average IQ of Australian aborigines is the low 60s and they’re the oldest surviving isolated anatomically modern humans. This corresponds to the mental age of an 11-year-old European. it’s possible to learn basic life and survival skills and live independently.
Average African IQ (if we throw out the extreme bottom) is in the low seventies ~71. 70 is the beginning of ‘intellectual disability’. So there is ‘nothing wrong’ with africans.
There is a gap here in the 75-85 range. It’s important to understand that people in this range cannot serve in the military as there are absolutely no functions that they can perform without greater risk to materials, self, and others. Why this gap exists is something I’d like to understand.
The band across North Africa, the Levant, Iran, Pakistan (which is the group I don’t know how to name, and call ‘iranics’, but others call south eurasians has an IQ of about 85. Same for native Americans. This appears to be the ‘normal’ basal eurasian human IQ, absent climate ‘selection pressure’. This is also the ‘problematic’ spectrum where people are both aware of their limitations, frustrated by them, and able to plan and execute crimes. I use the term the ‘evil 80’s’.
SE Asia (which should include part of southern india) comes in at around 90. (same with turkey but it’s due to european admixture).
Next is Europe outside of the southeast at 100, and east Asia at 105. But both Europe and east Asia have undergone political ‘natural selection’ under various forms of manorialism (and aristocracy).
I can and others have, think of explanations for northern IQ advantages other than political selection, but I don’t think any are necessary.
Examples of cranial capacity
East Asians ~1416/105 (very high variability in the data)
Europeans ~1369/100 (low variability in the data)
Africans ~1282/71 (low variability in the data)
Aborigines ~1199/62
Bushmen: ~1250/55
Early Hominids
Neanderthals: 1,500–1,740 cm3 (92–106 cu in) (bigger brains)
Homo erectus; 850 – 1100 cm3
Australopithecus anamensis; 365-370 cm3
Australopithecus afarensis; 438 cm3
Australopithecus africanus 452 cm3
Paranthropus boisei 521 cm3
Paranthropus robustus 530 cm3
Apes
Gorillas: 340–752 cm3 (20.7–45.9 cu in)
Orangutans: 275–500 cm3 (16.8–30.5 cu in)
Chimpanzees: 275–500 cm3 (16.8–30.5 cu in)
Source date (UTC): 2020-09-25 00:53:00 UTC