The Human Brain Has been Getting Smaller Since the Stone Age

[Universe]

https://www.discovermagazine.com/planet-earth/the-human-brain-has-been-getting-smaller-since-the-stone-age

[Celto-Germanic]

Is this news? Bronze age and Paleolithic people had average brain ccs 1550+, now in the modern era 1450 cc is considered very big. I think it is mainly due to millenia of agriculture, sedentary life and civilisation. On an educated guess, I think modern people have gotten smaller brains, but have more unique or refined psychological faculties beginning with the need for arithmetical and algebraic thinking, at least compared to the people of the Paleolithic and neanderthals (I'm not so sure about Bronze age though).

https://files.catbox.moe/irc6wb.png

[Radimir]

I could believe that.

[EM78GREENSAVANNAH]

Homo domesticatus

[Celto-Germanic]

It hasnt been completely uniform by the way. It reversed a bit in some places between the middle ages and now, also during the bronze age

https://www.nature.com/articles/4813122?foxtrotcallback=true

[Ascended]

yet IQ has been rising steadily ever since it's been recorded (Flynn effect)...explain that?

My explanation: one of these claims is untrue.

[Celto-Germanic]

yet IQ has been rising steadily ever since it's been recorded (Flynn effect)...explain that?

My explanation: one of these claims is untrue.

Like I said I think people can develop cognitive adaptations without necessarily having larger brains. I know its' a cheap examples but dolphins and elephants both have larger brains than humans do, and both are very cerebral and intelligent animals, but they aren't as smart as a human is. The Flynn effect certainly hasnt been uniform either, in some places its the been the opposite. Remember this is over 10s of 1000s of years.

[pulstar]

Its not only the size that matters by connectivity of neurons

[Celto-Germanic]

You also have to take into account that hunter gatherers ate much heftier diets and had to constantly be active too and avoid natural disasters like blizzards, deal with super predators, remember everything, one false move and you'd die. They uncovered hominids in South Africa who had subsisted on plant and fibre based diets and they all had noticeably small brains, compared to people who ate meat, dairy, fish and especially shellfish, who would have bigger brains

[Celto-Germanic]

http://archive.fo/vVAfl

"To make the problem worse, the mutation also hinders the production of beneficial Omega 3 fatty acid which is protective against heart disease. Although it may not have mattered when the mutation first developed, since the industrial revolution there has been a major shift in diets away from Omega 3 – found in fish and nuts - to less healthy Omega 6 fats - found in vegetable oils."

Many vegetarians also struggle to get enough iron, vitamin D, vitamin B12 and calcium which are essential for health. One study found that vegetarians had approximately five percent lower bone-mineral density (BMD) than non-vegetarians.
However other research suggests vegetarianism lowers the risk of diabetes, stroke and obesity.

[Celto-Germanic]

Chapelle Aux Saints Neanderthal, 1620 cc brain

http://dase.laits.utexas.edu/media/efossils/small/000469622_640.jpg

Combe Capelle, 1570 cc brain

https://greaterancestors.com/wp-content/uploads/2016/12/Combe_Capelle-skull2.jpg

Amud-1 neanderthal, 1740 cc brain

https://pbs.twimg.com/media/Dg10eE0WsAAiqyg.jpg

Apparently there was a native american skull uncovered amongst the Algonquin (Silvid) Indians - homo sapiens - which was 2100+ cc. But I can't find a good online source.

If you look at descriptions of modern humans in many textbooks it will say the average for people is 1250-1350cc

[Dick]

yet IQ has been rising steadily ever since it's been recorded (Flynn effect)...explain that?

My explanation: one of these claims is untrue.

Flynn effect is untrue

[Celto-Germanic]

Flynn effect is untrue

I would say it's untrue as a universal rule

[Celto-Germanic]

yet IQ has been rising steadily ever since it's been recorded (Flynn effect)...explain that?

My explanation: one of these claims is untrue.


Like I said I think people can develop cognitive adaptations without necessarily having larger brains. I know its' a cheap examples but dolphins and elephants both have larger brains than humans do, and both are very cerebral and intelligent animals, but they aren't as smart as a human is. The Flynn effect certainly hasnt been uniform either, in some places its the been the opposite. Remember this is over 10s of 1000s of years.


A scientific study that backs up my guess, saying there are signs of cognitive complexity arising in human brains during the lower paleolithic, not to do with brain size.

https://www.sciencedaily.com/releases/2010/11/101103171451.htm

After analysing this data, the researchers discovered that both flake and hand-held axe manufacturing techniques were equally complex, requiring the same kind of hand and arm dexterity. This enabled the scientists to rule out motor skills as the principal factor for holding up stone tool development.

The team deduced from their results that the axe-tool required a high level of brain processing in overlapping areas of the brain that are responsible for a range of different functions including vocal cords and complex hand gestures.

[Celto-Germanic]

Another argument

https://www.sciencedaily.com/releases/2020/09/200925113353.htm

Primate brain size does not predict their intelligence - study claims Lemurs as intelligent as Chimpanzees

Chimpanzees, gorillas and orangutans are our closest relatives, and like us they have relatively large brains and they are very intelligent. But do animals with larger brains really perform better in cognitive tests? A research team from the German Primate Center (DPZ) -- Leibniz Institute for Primate Research in Göttingen has for the first time systematically investigated the cognitive abilities of lemurs, which have relatively small brains compared to other primates. Conducting systematic tests with identical methods revealed that cognitive abilities of lemurs hardly differ from those of monkeys and great apes. Instead, this study revealed that the relationship between brain size and cognitive abilities cannot be generalized and it provides new insights into the evolution of cognitive abilities in primates.

For the first time, researchers of the "Behavioral Ecology and Sociobiology Unit" of the DPZ have now tested three lemur species with the PCTB. Lemurs are the most basal living primates and represent the evolutionary link between primates and other mammals, which is why they serve as a living model of primates' origin of cognitive abilities. The study examined ring-tailed lemurs, black-and-white ruffed lemurs and grey mouse lemurs, which differ in their social system, diet and brain size, not only among each other, but also compared to the previously tested Old World monkeys and great apes.

The results of the new study show that despite their smaller brains lemurs' average cognitive performance in the tests of the PCTB was not fundamentally different from the performances of the other primate species. This is even true for mouse lemurs, which have brains about 200 times smaller than those of chimpanzees and orangutans. Only in tests examining spatial reasoning primate species with larger brains performed better. However, no systematic differences in species performances were neither found for the understanding of causal and numerical relationships nor in tests of the social domain.

Brain size I think is related more to broader contemplative intelligence, reflection, conscientiousness and awareness but problem solving analytical arithmetical intelligence is more to do with cognitive adaptations. Both correlate with intelligence though.