Summary: I agree with Billy on some points and disagree on others; I nearly completely agree with Tyler and completely agree with Sabertooth. The key point that no one disputed and is universally accepted by scientists is that increased brain growth provided increased intelligence going from Australopithecines to Neanderthals and Cro Magnons. I haven't seen a good explanation of why we should ignore brain size completely after that point.
I'm surprised I didn't get more backlash. Good to see that political correctness doesn't appear to run amok here.
Details:Hi PaleoPhil,
Asians are supposed to be the most intelligent race in terms of IQ and they are usually the smallest, skinniest people around.
If you look at the map, you'll see that plenty of Asians, including Chinese, are in the bigger-brained areas. The research up to this point is pretty limited, though, as it's so politically incorrect, so it will be interesting to see what future research finds.
I'm not necessarily refuting the information you put forward, but it may well be something like, for example, the skull grew so that there could be more fat to keep the brain warm.
Of course, we can imagine anything. It's putting our speculations to the test that is the important thing, either by finding research to support them or doing our own tests.
Like I said before, fat can be made from any of the macronutrients including carbs and protein. I haven't seen an animal fatter than an elephant and it doesn't eat meat.
Wild elephants may not be as fat as you think and body fat is not correlated with brain fat, AFAIK. More importantly, a key factor for intelligence is brain to body ratio, which is quite low in elephants and much higher in humans.
I would suspect that the evolution of the human brain was something which involved a lot of different factors, a lot of them seemingly very small and insignificant, such as the inclusion of slightly more omega 3 than usual. That and the adaptability of the human organism as a catalyst. But that's just my theory.
That's pretty much what I said, except I would say significantly more omega 3, likely sourced from eating brains and marrow of wild animals, fish and shellfish. Dr. Andreas Eenfeldt mentioned that 25% of the human brain is omega 3 FA and 65% is saturated FA. We are literally fatheads
and scientists like Loren Cordain hypothesize that eating brains and other foods rich in omega 3 (and I would add, saturated fat) provided the raw material for the evolution of larger hominin brains.
I don't know if Eskimos are smarter than the general population,
I don't know either, as brain size is not the same thing as intelligence, but the evidence does show correlation (which is not causation, of course).
but perhaps their increased brain size is because of all the omega 3 and DHA that they get from the fish they eat?
and sea mammals and land mammals (as the resource material for the brain), perhaps in combination with the demands on the brain of the Arctic environment (the selective pressure).
Asians (especially Japan) tend to eat a lot of fish too.
Yes, and they've been eating them for thousands of years or more and in the past they were largely wild fish (omega-3 rich). It is a bit surprising that the Japanese and Scandinavians don't rank higher on that skull-size map, given the history of seafood consumption. It looks like the areas where caribou and reindeer were the staple traditional foods have the largest skull sizes.
I'm afraid that the 10 percent of the brain idea is just an urban myth. It started early in the past century but, since then, scientists have worked out that all parts of the brain are used.
Quite right. It gets repeated so often that it's taken as gospel.
As for intelligence, I would concede that larger brain-size is a little indicative re intelligence(that is people with larger brains will, presumably, usually have above-average intelligence, though not necessarily genius-level). However, I am convinced that cultural behaviour, among other things, also plays a part in intelligence.
I agree.
Also, I'm a sceptic of the accuracy of IQ tests, since I found that I started doing better on IQ tests in general, after doing 1 or 2 of them.
The evidence is imperfect, so I'm sure there will be plenty more debate in the scientific community on this.
A side note--Seth Roberts, myself and others have reported improved brain function on Paleo and raw Paleo diets. Seth even does his own little intelligence tests and tracks which foods give it a boost. So your own brain function may well have improved. We know that brains can shrink on deficient diets, such as in the vegan and vegetarian brain shrinkage case, so it's not far-fetched to think that some reversal of that shrinkage might be possible via improved diet, as well as improved neural connections and so on.
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Excellent points, Sabertooth.
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Sabertooth, I'm not sure I understand where you're coming from. I don't see how a cat could not benefit from being smart.
Benefits from evolutionary changes, like increased intelligence from larger brains, don't come without a cost. Cats already have sufficient intelligence to hunt and kill prey with their speed, fangs, claws, strength and so on. Brains consume a lot of energy and larger heads could reduce speed, balance, agility, etc. If the energy cost and other costs of a larger brain were more than offset by the intelligence gained, then cats would have evolved larger brains, but it apparently wasn't, so they didn't. Otherwise, all mammals would evolve larger and larger brains and all would have huge heads. LOL
I don't think this would apply in the tropics and only for short periods of time (on an evolutionary scale) in mid latitudes.
The tropics that H. erectus and H. sapiens evolved in were savannahs mixed with forest, lakes, rivers and seasides (the balance of which shifted with each major climactic change) that were teeming with megafauna. It wasn't like the banana forest that vegans dream up, if that's what you're thinking (bananas aren't even native to Africa, BTW).
Lastly, if our brains evolved on a diet of high fat, why didn't our guts? Why didn't our teeth?
Who says they didn't and why? Our guts actually did reduce in size as animal fat and meat intake increased and intake of tough, fibery foods declined, and continued to shrink as cooked foods were introduced and increasingly consumed.
Carbohydrates are still preferred as an energy source. I don't care what any Stefansen or any scientists say but I feel like hell in ketosis.
Carbs are a useful energy source, but that is beside the point, as Tyler pointed out well.
I disagree with Stefansson on some points too, and surprisingly, he actually was OK with including some carbs like potatoes in his recommended diet and he reported witnessing Eskimos eat wild potatoes, which are called Eskimo potatoes, BTW. You won't see zero carbers talk about Eskimo potatoes much, because they don't fit their preconceived notions. Both the notions of the banana jungle paradise and the zero-carb Eskimos are largely based on myth rather than evidence.
The key point that no one disputed is that increased brain growth is universally recognized by scientists as providing increased intelligence going from Australopithecines to Neanderthals and Cro Magnon; it's only the recent bit of the last 30,000 years or so where they start to abandon this view and suddenly say that brain size magically doesn't matter any more. Rather too convenient, I think, and possibly mainly due to towing the line of political correctness so as to stay employed and continue receiving funding, and perhaps because people generally don't like to think that any group of people is born with a significant advantage, especially among committed leftwing ideologues like the recently departed Stephan Jay Gould.
