The Human Brain Has been Getting Smaller Since the Stone Age

[Celto-Germanic]

Chapelle Aux Saints Neanderthal, 1620 cc brain



Combe Capelle, 1570 cc brain



Amud-1 neanderthal, 1740 cc brain



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/release...1103171451.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/release...0925113353.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.