One of the HBD’s supposed biggest findings is that IQ increases as a function of distance from the equator. The theory holds that those groups who experienced colder winters were selected for levels of higher g and they passed on their high IQ genes. Cold winter theory is supposed to explain why some races have higher levels of achievement and IQ than others. However, after a conversation with PumpkinPerson about cold winter theory and tool use, something clicked in my head: the real reason for the increase in brain size in peoples further from the equator wasn’t for IQ, but expertise capacity. I will go through the reasons how and why our brain size increased for the capacity for expertise and not IQ and hopefully put the cold winter theory to rest for good.
Tool complexity/use and brain size
PumpkinPerson is one of the biggest champions of the cold winter theory, writing: “I don’t even understand how one can believe in racially genetic differences in IQ without also believing that cold winters select for higher intelligence because of the survival challenges of keeping warm, building shelter, and hunting large game.” He wrongly assumes that climate theories are the only explanation for racial gaps in intelligence when other theories (such as differing types of sexual selection) could explain the gap just as well. However, since Rushton and Lynn have pushed this theory for 30+ years, it’s still engrained in the minds of some people. It is hard to change your views in the face of contrary data, but for those of my readers who are proponents of cold winters increasing IQ, I hope tonight I can sway you into believing that brain size increased as a function of climate and tool-making, not for IQ.
In his article he cites Richard Lynn (2006: 148), saying:
… 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.
I, of course, don’t doubt that peoples in cold northern environments need more (and complex) tools compared to those in tropical climes. But I look at it from a different point of view.
This is based on the research of Terrence (1983) and his study on time budgeting and hunter-gathering technology. The data does show that the number of tools correlates to latitude, but he leaves out that it also correlates with mobile and immobile and diet. That’s a pretty big factor. Of course, the type of animals around and what you need to do to kill/extract the meat involves a certain type of complex tool. In northern environments, a few more tools are needed to survive, so what? That doesn’t really mean anything. The whole brain-size/IQ latitude cold winter theory can be explained in another way.
Tool use increased our brain size throughout our evolutionary history, so with Arctic peoples living in cold climes where having a bigger brain is advantageous, they already had more neural columns for expertise capacity. The construction of complex tools increased brain size along with the colder climate. If tool use can explain part of the increase in our brain size over 3 million years, why can’t it partly explain why Arctic peoples—who use more (and complex) tools—larger brains over those further from the Arctic? Because brain size increased for expertise capacity, not IQ. Since they had bigger brains they were able to master the creation of complex tools, which further increased their brain size along with colder climates. Those who could make better tools could pass their genes, selecting for bigger brains.
Brain size increased for expertise capacity, not IQ
Table 3.1 in Torrence (1983) makes reference to technounits, a way to gauge the complexity of a particular item (Collard et al, 2011). Those in northerly climes do have tools with higher technounits, however, that’s showing that what is needed to construct the tools is a high capacity for expertise.
Skoyles (1999) posits that brain size increased for expertise capacity, not IQ. Bigger brains cause extreme complications during birth, calling for Caesarian sections (which is driving the evolution of bigger heads), so selection for bigger brains must have been advantageous in another way. Skoyles cites studies showing that microcephalics have brains in the average range of Erectus while having IQs in the normal/above average range. This implies that Erectus could have had IQs in our range, and that selection for bigger heads was caused by something else—the need for expertise.
Even then, the correlation between brain size and IQ cannot be invoked here. A .33-.4 correlation between brain size and IQ still leaves a lot of room for people to have brain sizes in the range of Erectus and still have above average IQs. Assuming a correlation of .51, that leaves 74 percent of the brain size/IQ correlation unexplained. This leaves a lot of room for other explanations for the remaining variance.
So if you think of the implications of Skoyles’ (1999) paper in regards to human races and the quote provided from Lynn (2006), you can look at it as Arctic peoples needed to be able to learn how to make complex tools which required a certain amount of expertise. Acquiring certain types of expertise does lead to certain local changes in the brain due to environmental demands, for instance in racecar drivers (Bernardi et al, 2013) and in taxi drivers in London who were “on The Knowledge” (Maguire et al, 2000). Tool use did cause increases in our brain size in our ancestral past, so the fact that Arctic peoples have bigger brains but lower IQs is explained by brain size being selected for expertise (their expertise to make their numerous tools) and cold climates but cold temperatures do NOT explain intelligence differences between the races.
Indeed, there is evidence that ‘chunks’ form in the brain due to certain types of expertise (Gobet and Simon, 1998). In their study, Gobet and Simon showed that Chess masters used significantly more chunks, extending the chunking theory ” to take account of the evidence for large retrieval structures (templates) in long-term memory.” This study is direct evidence for Skoyles’ contention on “informational chunks (Skoyles, 1999) lending credence to the claim that people who master something have more information stored in their ‘chunks’.
Furthermore, high and low skill employees organize their conceptual knowledge about a problem differently (Lamberti and Newsome, 1989). Low-skilled workers performed much faster on the tasks that needed concrete information organization whereas high-skilled workers were better on the more abstract concepts. Overall, both high- and low-skilled workers processed the same information differently. This study has nothing to do with IQ itself, just how high- and low-skilled workers process information differently (which may come down to ‘chunks’ in the brain).
Chase and Simon (1973) show that the amount of information extracted during a memory and perception task is directly related to the amount of time the individual has played chess. They state that chess skill is “reflected in the speed with which chunks are perceived in the perception task and the size of the chunks in the memory task.” Of course, you can’t just throw anyone into a chess game who has never played before—IQ be damned—and expect them to do well. You need to hone your strategy and skill over time by noticing all types of moves, thinking ahead and guessing what your opponent will do ahead of time. This all takes time playing the game, and since people who have played longer can more easily tap into the ‘chunks’, this shows that chess skill is largely a function of time spend playing (note: IQ is still important, of course. Just, practice makes perfect and one with practice and a low IQ will beat someone with no/little practice and a high IQ).
Expertise does, indeed, take deliberate practice. Practice DOES make perfect.
Our brains increased evolutionarily speaking as to acquire more expertise. Bigger brains (and therefore bigger heads) cause problems with childbirth and so natural selection must have selected bigger brains since they increase expertise capacity. The fact that there are numerous people in the world with Erectus-sized brains and IQs in the normal/above average range lends credence to the claim. Erectus could have possibly had intelligence level near our own. But what really needs to be thought about here is this: It just so happens that the brain size increase corresponds with the beginnings of our modern gait and pelvis (Lieberman et al, 2006). The beginnings of cultural acquisition and transference began around that time (Herculano-Houzel and Kaas, 2011) and so our brain size would have increased due to cooking allowing us to have the energy for a bigger brain with more neurons.
Of course Erectus would need to become an expert with the new-found technology he acquired. Over time, the more ‘expert’ Erectus would have passed their genes on, both for increased brain size and expertise, and the hominin brain size then increased.
Looking at racial differences in brain size while thinking about how expertise capacity increases brain size and thinking about tool use/complexity of Arctic peoples is an alternate (and in my opinion) better theory of explaining racial differences in brain size. I obviously don’t believe that brain size differences cause IQ differences, the brain size differences are a function of climate and tool use/complexity. To make complex tools you need a sort of ‘expertness’, which, as Skoyles argues, causes brain size to increase. This explains the so-called anomalous Inuits with a brain size equal to that of East Asians but with an IQ in the low 90s.
Put simply, complex tools+cold winters+ cooked food=big brains. Cold climates DO NOT by themselves CAUSE higher levels of g. It’s just a correlation, it does not mean that it is causal. Big brains retain heat better in the cold whereas smaller heads cool better. That’s the reason for racial brain size differences, but climate and brain size in and of themselves do not CAUSE racial differences in IQ.
I now believe that sexual selection is a cause for racial differences in IQ, but that’s for another day.
Bernardi, G., Ricciardi, E., Sani, L., Gaglianese, A., Papasogli, A., Ceccarelli, R., . . . Pietrini, P. (2013). How Skill Expertise Shapes the Brain Functional Architecture: An fMRI Study of Visuo-Spatial and Motor Processing in Professional Racing-Car and Naïve Drivers. PLoS ONE,8(10). doi:10.1371/journal.pone.0077764
Chase, W. G., & Simon, H. A. (1973). Perception in chess. Cognitive Psychology,4(1), 55-81. doi:10.1016/0010-0285(73)90004-2
Collard, M., Buchanan, B., Morin, J., & Costopoulos, A. (2011). What Drives the Evolution of Hunter–Gatherer Subsistence Technology? A Reanalysis of the Risk Hypothesis with Data from the Pacific Northwest. Culture Evolves, 341-358. doi:10.1093/acprof:osobl/9780199608966.003.0020
Dr. John R. Skoyles (1999) HUMAN EVOLUTION EXPANDED BRAINS TO INCREASE EXPERTISE CAPACITY, NOT IQ. Psycoloquy: 10(002) brain expertise
Gobet, F., & Simon, H. A. (1998). Expert Chess Memory: Revisiting the Chunking Hypothesis. Memory,6(3), 225-255. doi:10.1080/741942359
Herculano-Houzel, S., & Kaas, J. H. (2011). Gorilla and Orangutan Brains Conform to the Primate Cellular Scaling Rules: Implications for Human Evolution.
Lamberti, D. M., & Newsome, S. L. (1989). Presenting abstract versus concrete information in expert systems: what is the impact on user performance? International Journal of Man-Machine Studies,31(1), 27-45. doi:10.1016/0020-7373(89)90031-x
Lieberman, D. E., Raichlen, D. A., Pontzer, H., Bramble, D. M., & Cutright-Smith, E. (2006). The human gluteus maximus and its role in running. Journal of Experimental Biology,209(11), 2143-2155. doi:10.1242/jeb.02255
Lynn, R. (2006). Race differences in intelligence: An evolutionary analysis. Augusta, Ga.: Washington Summit Publishers.
Maguire, E. A., Gadian, D. G., Johnsrude, I. S., Good, C. D., Ashburner, J., Frackowiak, R. S., & Frith, C. D. (2000). Navigation-related structural change in the hippocampi of taxi drivers. Proceedings of the National Academy of Sciences,97(8), 4398-4403. doi:10.1073/pnas.070039597
Torrence, R. (1983). Time budgeting and hunter-gatherer technology. In G. Bailey (Ed.). Hunter-Gatherer Economy in Prehistory: A European Perspective. Cambridge, Cambridge University Press.
Well done, check out this latest comment from Melo,
One question, what are the differences in the measures we use to for expertise through cortical columns versus IQ as you did in your Hominids article?
In other words, what so we measure to understand each trait?
“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.”
Virtually all tropical peoples do this as well—in addition to making bows/atlatls /other projectiles—(and have since arround the early history of homo sapiens in Africa, along with bone points). (hafted thrusting spears with stone go back to heidelbergensis)
The overall tendency you mention could exist, but I am not sure—the reality semms at least more complicated.
Complex tools are often used in many cultures native to hot climates—some of which are arid or semi-arid like savannas (e.g. by the Pygmies and Bushman for instance, or other Africans) like—for instance—(other than the bows/projectiles), various complex traps (many of these are used in the wet tropics also e.g. Congo region), hunting/fishing nets, and the use of poisons in hunting (sometimes on their projectile points)
(the same would apply to some tropical/desert/savannah groups of Amerindians and Asians):
“Complex tools (and knowledge/practices are often used in many cultures native to hot climates”
” climates—some of which are arid or semi-arid like savannas, which can be quite harsh in various ways”
(e.g. by the Pygmies and Bushman—who store water in ostrich eggs shells throughout the desert—….”
…..hotter climates can be difficult to survive, as you have mentioned.
I reread the quote on Pumpkinoerson’s post, which says the Torrence study used the respective numbers of tools types as evidence. I suppose that could be part of the “complexity differential” claimed. But I’ll have to track down the original source to look into it.
Complexity was defined with “technounits”. My contention here is that since Arctic peoples made more and more complex tools, they got selected for bigger brains. Along with climate having an effect on brain size, this explains the so-called “anomaly” in regards to the Inuit, brain size and IQ.
Interesting addition to the theory. I was a C-Section baby with a big head heh. My ancestry is arctic (back a single generation) and although I don’t feel I’m a genius, I have a wide breadth of expertise. I seem to be able to retain more information than most people I know. Being able to retain more information can lead to breakthroughs because you see a broader picture especially if you pull information from different fields.
And autism correlates with over expertise and bigger brains. Well done. Finally:)
Seems like we finally agree on something. :^)
But not that cooking increased brain size, otherwise. Humans become smarter and invent non accidental cooking.
Cooking released the metabolic constraints on brain size. If we were, say leaf-eaters, we’d have substantially smaller brains.
I know that second argument you speak about. However, chimpanzees have been seen to have the cognition for basic fire us.
Correlation and not causality. Based on this theory the smarter would be fattier and carnivorous. Yes human brain require a lot of energy but this doesn’t mean this energy only can be found in “meat”. Remember natural selection. This is clear a kind of lamarckism. First humans start to cooking so some bizarre immediate organic transformation start in their brains and they become smarter, so they pass this changes to their sons. Don’t seems like that?? Yes and humans sophisticated this technique. Sorry I disagree in this part and yes I’m partially motivated because I’m vegetarian and ethical. Only partially because as I said above this sound Lamarckism.
We literally cannot support our big, energy-hungry brains with a leaf-based diet. There are metabolic constraints on brain size due to diet. Look at great apes. They need to spend 8-10 hours a day feeding to get enough energy to power their brains. If we ate the same diet we’d have to feed for over 9 hours to get enough energy to power our brains. That is not viable, obviously.
Right. But the group that eats only a plant-based, non-cooked diet won’t have as large of a brain as a group that cooks their food and eats meat. The survival of fat babies is very important in our evolution, which I’m going to cover soon.
We did eat meat before we began cooking, however. We processed it (smashed, minced, etc) before we ate it which decreased digestion time. The advent of cooking decreased digestion time even more.
Yes, but epigenetic changes from cooking took a long time to make a mark in our genome. Covered here: Genetic Changes from Cooking
Furthermore, through cultural transmission and acquisition (which, mountains of evidence show that it began with erectus, with cooking for instance), people learn to cook. Genetic potential can then be reached, but only when the metabolic constraint is overcome with a higher-quality diet. However, you are right in a way. Human culture in and of itself is Lamarckian.
I know. But you cook your food, correct? You’re not a raw-foodist, are you? If so, I have some bad news for you…:
Human Adaptation to the Control of Fire
I don’t believe the style of diet lamarckianly shaped human or non human evolution. Remember: It’s not meat it’s the protein that is important but still no have any substantiated study proving your points. When the relation is causal it’s mean universal, one thing based on current conjuncture will always cause other thing. Humans who prey and usually in places with less fruits, aka, tempered places, are those who evolved to have higher intelligence on avg.
Supposedly drink milk its important for the health but there are many people in the world who have natural intolerance with lactose and this don’t make them ill. And we have tolerance to drink milk and not upper necessity, this are two different things. But today most of nutritionists teach us that drink milk is extremely important for our health. Do you can see it?’
Cooking is a skill. Skills get passed down. Cooking/fire use was one of the first instances of cultural transference and acquisition (tool-making/use, etc). So since cultural transference is Lamarckian in nature, then cooking is Lamarckian.
That’s the point. The quality of the food is higher in meat compared to leaves—especially cooked. Look at great apes with their small brains and big bodies. Look at us with the opposite (though other factors are in play, obviously). It’s due to diet quality. It also takes less time to eat (and digest) cooked meat, and therefore due to the time saved from not having to forage/digest food, more things can get done (like constructing cultural niches).
If we were to eat a lower-quality diet as a species, would we see changes in our phenotype? Of course this occurs because of environmental shifts, which is the point. Bigger brains need higher quality kcal/nutrients to grow and stay nourished. Without that, big brains would not be possible.
This is an example of niche construction. Populations who are less lactose intolerant constructed niches in which the allele for the ability to digest lactase was needed. Populations that didn’t have a higher chance of being lactose intolerant.
I don’t really see it. Milk has an unbalanced n3/n6 ratio. It negatively affects cognition (more so in women).
”Cooking is a skill. Skills get passed down. Cooking/fire use was one of the first instances of cultural transference and acquisition (tool-making/use, etc). So since cultural transference is Lamarckian in nature, then cooking is Lamarckian.”
Cultural is not lamarckian. You must need grasp what Lamarck want to say when he created his theory. Cultural is also invent or discover a way to do things and teach it to other generations. Lamarckian is you start to eat baked food, become smarter instantaneously and this changes be passed to your descendents. Very unlikely.
”That’s the point. The quality of the food is higher in meat compared to leaves—especially cooked. Look at great apes with their small brains and big bodies.”
Big bodies* I thought muscular bodies, it’s not the same than taller. what you want to mean is not*
Diet quality is relative. To the body synthetize protein that is contain specially in meat, it’s good to the faster lifestyle, but it’s possible have a slow lifestyle without the fast-like power protein of meat give us. Indeed, because this faster lifestyle, people who are adapted to this lifestyle tend to become fattier in sedentary lifestyle. In other words, not so good our bodies requires a lot of energy to be spent.
But non-human primates tend to be brighter too.
”If we were to eat a lower-quality diet as a species, would we see changes in our phenotype? Of course this occurs because of environmental shifts, which is the point. Bigger brains need higher quality kcal/nutrients to grow and stay nourished. Without that, big brains would not be possible.”
Now you’re investing in ”low-quality diet” and supposed ”high-quality diet based on meat”.
Again, first we have organic changes caused by selection and cultural adaptation, in the second. One thing cannot preceed other. ”We” become smarter enought to cook in intrincate ways the food. And not, the cooked food make us smarter. Bigger brains require more energy, LOGICALLY speaking, but we can take this energy in faster or in slow ways. What’s matter is if this organic advantage will be truly translated in real world advantage or survive.
”This is an example of niche construction. Populations who are less lactose intolerant constructed niches in which the allele for the ability to digest lactase was needed. Populations that didn’t have a higher chance of being lactose intolerant.”
My example about milk is analogous to meat. You’re generalizing, seems, as if meat is required for everyone, while it’s not. It’s possible to adapt to new diets, only if people have restrictive natural diets.
Indeed seems no have very good studies proving that meat is fundamentally important and as onivorous, i believe many if not most human beings can adapt to the vegetarian diet and with subsequent selective pressures people can become adapted to this diet.
I said selection happen before cultural adaptation but the otherwise is also possible, what is not possible is lamarckian way, maybe we can take some good points of his theory, but the core-theory is or appear to be very wrong.
A example: we have a healthy couple who have a schizophrenic son. He marry a woman [times of sexual diversity, 😉 ] and they have a schizophrenic girl.
Even it ”sound” very vaguely ”lamarckian-esque” it’s not, because the guy must to do ”repetitive effort” to, bizarrely hypothetizing, become schizo.
Epigenetics is the new lamarckianism, eternal genetic confound.
Lamarckism—the idea that an organism can pass on characteristics that it has acquired during its lifetime to its offspring
That’s exactly what epigenetics is.
Culture—a : the integrated pattern of human knowledge, belief, and behavior that depends upon the capacity for learning and transmitting knowledge to succeeding generations
Do they sound alike to you?
Do parents not teach their children anything? Is that not Lamarckism?
Great apes eating leaves eat for–at times—ten hours per day, averaging 8-9. It’s not metabolically viable—or possible—to have a brain as large as ours consuming low-quality energy.
This is literally gibberish.
Brains our size need a high-quality diet, a diet that eating a vegetarian diet, such as what great apes eat, cannot give us. Cooking gelatinzes collagens and breaks down cells walls to make food easier for digestion, which then shrunk our teeth and guts. The high-quality nutrients from the cooked food allowed our brains to grow larger. Leaf-based diets don’t do that.
Taking in the amount of energy in a ‘slower way’, which I believe you mean eating leaves, etc, would take over 9 hours a day.
Cooking is a kind of cultural transmission—the first of its kind (along with tool-use/making).
Since chimpanzees are omnivorous when the opportunity arises, the last common ancestor (LCA) probably was too.
Cooking became biological adaptation between 275-765 kya.
Metabolic constraint imposes tradeoff between body size and number of brain neurons in human evolution
Look at the definition of ‘culture’ and ‘Lamarckism’.
I agree. Epigenetics short of proves Lamarck right.
Second, cultural evolution is direct and Lamarckian in form: [t]he achievements of one generation are passed directly to descendants, thus producing the great potential speed of cultural change. Biological evolution is indirect and Darwinian, as favorable traits do not descend to the next generation unless, by good fortune, they arise as products of genetic change.—Gould, 1996 from Full House.
Do you believe in epigenetics?? And neo name for Lamarckianism, period.
I’m on the fence on it. I do find it interesting that it is pretty much Lamarckism, showing he was partly right (except it’s obviously not as radical as he thought—if there is a distinction between inheriting memories/stresses and inheriting lost limbs from a parent, for instance).
In your title of this post you already said big brain has been selected for expertise. So why you are arguing that it was cooking that epigenetically make us smarter?? It’s not contradictory? Do you must need choice. Or selection for expertise increase brain size or cooking.
Ok, i understand:
for you, cooking is the possible origin of higher human intelligence and after, humans will becoming more and more experts than generals.
I try to visualize this scene.
Lightning struck an animal, it died and began to burn. A group of humans coincidentally were close, or they arrived at the place and began to eat the meat of the dead animal. So this food, i mean, cooked meat, caused deep changes in their brains and they became more intelligent, like that overnight.
It even looks like the Gauls’ magic potion for super strengthness.
Just look at the animal kingdom and, more often than not, you’ll see that animals that eat meat are more intelligent (whatever that means in this context) than animals that eat leaves. If the food is tougher to find, then brain size will increase due to the cognitive demands. But the higher-quality nutrition also allows for brains to grow large—check some of my references.
Look at my example of tool use/brain size in regards to Arctic people in the article.
All the time the same bullshit…
you’re in fatal contradiction
It’s not you who advocate for the idea that ”no there such thing SMARTER’**”
”Humans are not smarter than damn ants”
What’s your problem to avoid internal contradictions***
I think you’re in the wrong place, science and other high order human knowledge IS must a place for neutral people, instead completely neutral ones are nonexistent, and you’re the complete otherwise side of this spectrum.
I no have guilt because i’m quasi-always in the right side, moral or neutral/”scientific” ones.
first, i don’t know if this ”smarter animals are always carnivorous” is a correct statement, if this is the rule, i hope and i expect will be exceptions.
second, a bunch of correlations resulting in this product: living beings who need hunt its food ”need develop” strategies to do it or in other words, depending the level of selective pressure, they are being selected to be smarter to be able to develop better strategies, IF this CORRELATION: hunter and intelligence [whatever it mean] be the rule…
third, again, we have selective pressure that result in higher-demanding organism who result in carnivorous diet. Carnivorous are predators, so you are saying they are smarter* The concept of intelligence among non-human living beings are very complex, difficult to stablish a significative hierarchy, only with the mammals. Indeed, intelligence and behavior may be translated as the same thing for most of them, but not for us, because our disconnection between thinking and action.
so, it’s the otherwise process, bigger brains has been selected in some species and may result in food that are highly energetic as meat. You’re putting the cart load or cart forward the horses.
Humans who hunt and not who prey
So we can think if living in cities also increased human intelligence only by the reason to live in city…
By now I think you just have bad conjectures and news.
I don’t understand. Please reword this.
Intelligent people choose to live in the city.
The same bullshit you lost yourself, the basic problem of causality versus correlation. I know you LOVE this stupidly clever theory, because as you are a nutritionist, so you love the idea that nutrition can have a enormous impact on human ”intelligence” [i know, it’s RELATIVE, ;)], because it put your expert area in the middle of the human evolution stuff, but not, so sorry for you, and for other people and beings who are dragged by your gigant ego, childish incapacity to accept certain truths that are directly contrary to your beliefes.
It’s a ”politically correct” theory that says basically ”higher ‘human’ intelligence appeared by epigenetic reasons”.
OK how about this. Let’s say an asteroid strikes the earth. The sun gets blocked sour for decades. Most of our livestock die. We eat a lower quality diet than we do now, with little high quality nutrition. Would our brains and bodies become smaller due to the environmental change?
So you’re telling me that nutrition didn’t, in part, drive our evolution? The paper below proves my point. If we ate a plant-based diet, we’d have to feed for over 9 hours to power our brains. Does that seem metabolically viable to you? Not at all.
Read the paper below then get back to me.
Metabolic constraint imposes tradeoff between body size and number of brain neurons in human evolution
… in part…
In part, yes, and not ”essentially” as you’re suggesting, it’s different, very different.
My friend, please read the paper. Read the quotation I provided, get back to me when toy read it. Cooking increases the amount of calories that are able to be digested, whether it’s plants or meat.
For every billion neurons a primate has, 6 kcal has to be allocated to power the brain. We have about 86 billion neurons, meaning that we need over 500 kcal to power our brains over day. If we didn’t cook and eat meat we’d need to feed for over 9 hours per day to power our neurons. It’s not metabolically viable on a plant based diet.
If you’d read the paper I’m providing you you’d be able to converse better in this conversation.
Here we show that metabolic limitations that result from the number of hours available for feeding and the low caloric yield of raw foods impose a tradeoff between body size and number of brain neurons, which explains the small brain size of great apes compared with their large body size. This limitation was probably overcome in Homo erectus with the shift to a cooked diet. Absent the requirement to spend most available hours of the day feeding, the combination of newly freed time and a large number of brain neurons affordable on a cooked diet may thus have been a major positive driving force to the rapid increased in brain size in human evolution.
”OK how about this. Let’s say an asteroid strikes the earth. The sun gets blocked sour for decades. Most of our livestock die. We eat a lower quality diet than we do now, with little high quality nutrition. Would our brains and bodies become smaller due to the environmental change?”
But the highest-demanding organisms will die because lack of food abundance while those who are shorter or in little size will be likely to survive by self-evident reasons.
There are some animals who will likely reduce their shape IF they have some ”metamorphic genes” or if size, in general, is a more environmentally demanding feature.
What’s happened with dinoussaurs, the biggest ones dies and the very shorter survive in more numbers evolving for some ”modern” species.
My doubt is: some people will become taller whatever the place they are [fixed genes*], other people only become taller if they have ”environmental interventions”, for example, quantitatively ‘rich’ diet.
In extreme conditions very demanding-energy organisms will likely to die in more numbers than those with less demanding-energy. It’s natural selection.
But there is the possibility for us to become smaller, ONLY if we have less-fixed-but-available genes for size or stature.
I will not waste my time, i’m already wasting my time here.
Before i read your precious papers, refute my comments. You create a good example the ”asteroid scenario” but, it’s easy to refute, it’s always a ”natural selection/epigenetic confounding”.
Seems you fall in love forever for this pseudo-quasi-science… only because you’re nutritionist, morally relativist and southern italian triggered… even if this theory is right, you’re not a good a propagandist, because you’re in contradictions all the time, you’re mister contradictions.
I think you don’t understand what you are quoting, you just put links without explain for yourself , with your words, what you are saying. It’s a classical leftist behavior.
I understand very well that bigger brains MAY be energetic-expensive but maybe we can evolve for bigger but economic brains, isn’t*
By now it’s conjectures, there is a larger limit of tolerance of food consume to not become anemic, there are people who don’t need eat too much to gain energy enough to not become anemic, there are people who are more adaptable to vegetarian diet, all this things seems you’re denying or despising.
You’re saying simply that natural selection have virtually no-importance for human evolution. It’s that you are saying.
Now, your example works against you because you’re simply forgeting what i talked: bigger organisms die faster and in higher numbers in extreme scenarios than little organisms by self evident reasons AND NOT ONLY ”poor” diet reduce its size. We no have a miniature of tirrex walking in the savanah or in any other places.
All the time is the same thing, and i already show you how absurd this idea appears to be: we have a bunch of hominids with ”little” brains and they start to eat cooked food/aka, meat, so they will becoming instantaneously smarter, exactly like a magic potion. So, if we start to do the same with other animals they will become smarter [WHATEVER IT MEAN, lol] * I don’t think so.
Because humans become smarter enough to cook their food in sophisticated ways there is this correlation.
This theory in its abstract is great, tho.
It really is. Cooking allowed metabolic constraints to be passed to allow for brain growth. Selection pressures FOR increased brain size include finding—and getting to—food that takes more cognition.
You don’t understand, i said your theory of brain size and expertise capacity and not IQ [general ‘intelligence’, whatever i mean] is good on abstract, in its core-idea but you lost yourself during the process.
Lamarck said that biological changes via repetitive effort would be genetically passed for the next generation. He was just wrong about that. And not, culture co evolution is not Lamarckian in the way Lamarck think. Culture is dependent of level of intelligence, generally in qualitative and in quantitative ways (cultural techniques), levels of social cohesion and predominant type of personality to be passed intergenerationally and usually culture follows the evolution or changes in all this variable.
Lamarck was a pioneer in genetic confounding.
Culture can also change due to an environmental shift, speeding up change to the genome in two ways.
”Culture can also change due to an environmental shift, speeding up change to the genome in two ways.”
Not in the way you’re thinking.
Culture or ”selective pressure result” of certain organism into certain environment, the first being selected to reflect in progressively perfect ways the ”energetic and/or main features of environment they are”.
Culture co evolution is basically what natural environment is to the non human living beings, humans created natural laws for themselves instead be directly shaped by natural environment. So we have a culture and people who are fittest with this culture, at priori, will increase their own gene pool, but usually, most of complex societies, aka, human farms, it’s not the material fittest ones, aka, rich and or powerful rulers, who have becoming prevalent but the best subservient.
Other animals have a form of ‘culture’ as well. For instance, orca whales are showing speciation due to cultural differences!
I can see this. However, the rich and powerful rule over the subservient.
Culture does shape a lot of biological differences—differences that, with the advent of traveling where we want ‘in the blink of an eye— that will soon disappear.
Cultures tends to reflect or always reflects intrinsic or genetic features of organisms, seems, you don’t learn nothing with HBD.
Yes, culture is the reflection or way of life of certain organism.
Humans are essentially as ants or any other bigger collective species.
Culture only really or literally can shape a population changing their selective pressures among humans. Environmental changes that usually can altered organisms-demands as well their way of life OR culture. Culture is not a literal thing, exactly, it’s a reflection or a expression of literal organic things.
Indeed, environmental demands AND culture can be treated as the same thing. The difference is that we call our artificial environment structures as culture while it’s basically the same thing that ”environmental/environment demands”.
… can altere and not ”altered”
Ants also select for subservient ant workers while the rulers are a minority.
It comes down to this: small-brained people can have IQs in the normal range. If small-brained people can have IQs in the normal range, then large brains are not needed for high IQs. If large brains are not needed for high IQs, then some erectus may have had IQs in the modern range.
Since large brains consume so much energy, along with birth implications for both the babe and the mother—including a larger pelvis for a woman which impedes bipedal movement, especially when running (Skoyles and Sagan, 2002)—then due to the fitness aspects associated with large brains, along with large brains not being needed for high IQs must mean that our large brains evolved for another reason—which John Skoyles believes is expertise capacity.
Now, when talking about fire, you have to understand that cooking food increases the energy content in the food—I have cited studies for this claim above. When thinking about fire, along with the other cultural acquisitons that erectus was known to possess, we can then say that the beginnings of cultural transference and acquisition began with erectus—even before then with the advent of stone tool-making. So expertise was needed in these critical times in the Homo radiation, and this is when we see brain size increases in the fossil record.
Neural plasticity and culture shaped our modern brains. Fire allowed us to pay for our large brains.
What is the explanation for Ashkenazi Jews who perhaps have a smaller brain size and are disproportionately represented in chess?
They have a brain size of about 1320 cc, that’s really only “low” for European standards, not Sapiens standards.
Plus the layout of the cortical columns, the main factor expertise in brain size, can be rather compact in the case of Anatole France.
“The brain of Anatole France is of an admirable form. It
represents a piece of real goldsmith’s work, the convolutions’ being
long and sharply delimited, well folded, pressed tightly together,
showing a very unusual degree of complexity. ”
Click to access brmedj08303-0040.pdf
Plus we need to consider that IQ is still important in being able to play chess once you control for expertise as well.
Coordinate System, Phil is correct. Their brain size is on the low end of Europeans, at about 1320 grams. However, cortical folding and neuronal columns, as Phil said in the case of Anatole France, are probably a factor here. I don’t deny that IQ matters for chess. But IQ tests don’t measure the capacity to attain expertise, along with many more traits.
Would not expertise capacity be reflected in IQ? Say, that tool use required more abstract thought or another skill set measurable by, to one extent or another by IQ, would we then not see this reflected in subtest?
I’m not RR but someone familiar with his work.
Expertise, as RR is defining to explain brain size along with climate, is basically the organization of information to do a task, not necessarily abstract thinking.
Here this shows that brain expansion of the cortex was involved more in sensory and language function than abstract thought.
And this one shows that, controlling for language, it was shown to correlate with expertise, similar to Skoyles’ examples.
“It turns out that this Acheulian cognitive network is the same one that comes online when a trained pianist plays the piano. This does not necessarily mean that early humans could play Chopin. But our result may mean that the brain networks we rely on today to complete complex tasks involving multiple forms of information, such as playing a musical instrument, were likely evolving around 1.8 million years ago so that our ancestors could make relatively complex tools to exploit energy-dense foods.”
My guess is that inventing new tools, not the spread or acquisition of building them, would be more correlated with IQ but if it was selected for in the same casual relation I’m unaware of.
Phil78, the website is not letting me reply directly to your message for some reason. That being said, I appreciate the reply, but I am still left with some clarifications needed, sadly.
“Here this shows that brain expansion of the cortex was involved more in sensory and language function than abstract thought.”
I was using abstract thought more as general example, but would not having expertise entail the need for more abstract thought to help understanding? You too mentioned verbal ability, would this not entail higher verbal IQ? Or is this expertise more in the function of memory, i.e. remember how to use a hammer in more various ways? Or is it, to put in simplified terms, ‘the ability to mentally manipulate information’?
“the organization of information to do a task”
Would this not be crystallized intelligence?
“That being said, I appreciate the reply, but I am still left with some clarifications needed, sadly.”
“I was using abstract thought more as general example, but would not having expertise entail the need for more abstract thought to help understanding?”
That may depend on certain IQ levels for each task. For instance, there is likely a IQ threshold for Chess but the additional expertise would make one better at chess due to experience compared to someone with less experience but a higher IQ.
“You too mentioned verbal ability, would this not entail higher verbal IQ?”
That’s really language comprehension and processing in the context of information, not necessarily the use of articulating language to solve problems.
“Or is this expertise more in the function of memory, i.e. remember how to use a hammer in more various ways? Or is it, to put in simplified terms, ‘the ability to mentally manipulate information’?”
Replace “manipulate” with “organize” and you got the idea.
“Would this not be crystallized intelligence?”
At least in part yes, however when people say “IQ” they typically refer to “raw” fluid ability despite tests also judging this as well.
In addition to expertise being involved in information however, it is also related to brain plasticity involved in learning new skills. See Taxi driving for instance.
However, within the distinction of Amateurs and experts, IQ didn’t correlate that well with the Multivariate reasoning involved in Music or chess.
I remember that there was more recent info on the topic, but that maybe due to IQ tests being different between the two in regards to the use of crystallized intelligence.
This could be related to the can of worms of IQ and it’s use in Psychology as a whole through the decades as this study partly notes.
This comment by RR also helps with some distinctions.
Once again, thanks for the reply. I understand now what the idea being proposed is, so cheers for that!~ One last question (sorry), wouldn’t this imply that we can then equalize brain sizes between the races via training in expertise? Thus showing causation possibly through environment for brain size differences?
This is on an evolutionary scale. I’ve shown how tool use is related to the capacity for expertise, how those I’m northern climes have more tools and larger brains than those in tropical climes, and shown specifically how expertise shapes the brain.
All racial differences are due to environmental differences over a long period of time which lead to genetic changes, whether it be natural selection, drift, mutation migration or epigenetic (which I know is hotly contested around these parts).
I also cosign everything Phil said.
In addition to expertise selection differences, smaller brains are ideal for hot climates as well, though it’s worth noting the higher brain sizes of the Bantu/Nilotic area of the great lakes.
Likely related to the diffusion of pastoralism over long periods of time by Nilotics.
In addition, modern discrepancies are also reflective in part of malnutrition, which may tie into the epigenetics RR mentioned before.
Ah, okay. I understand now. Thanks, guys~
“Even then, the correlation between brain size and IQ cannot be invoked here. A .33-.4 correlation between brain size and IQ still leaves a lot of room for people to have brain sizes in the range of Erectus and still have above average IQs. Assuming a correlation of .51, that leaves 74 percent of the brain size/IQ correlation unexplained. This leaves a lot of room for other explanations for the remaining variance.”
So brain size explains about .25 of the IQ gap? So brain size = (a wee bit of) IQ + expertise or just full blown expertise and .0 variation on IQ?
The former layout.
Yes, brain size explains 16 percent of the variance (.4 correlation between brain size and IQ). I used the high end of .51 (as Skoyles did) to show that even if it’s that high there is a ton of room for other factors in brain size increase.
occam’s razor. the big brain is what gould termed a “spandrel”. it was not selected for directly. it results from a larger head which is selected for by cold due to allen’s rule. the brain requires a lot of blood. the head dissipates less heat when it’s larger and more spherical. a larger object has a lower surface area to its volume.
eskimos have larger brains than any other people. russians have larger brains than western europeans, and their heads are rounder. brain sizes have shrunk since the last glacial maximum.
what is more likely is that language and the human brain developed simultaneously. tom wolfe’s theory is that language is a tool. the human hand is adapted to tool use. the ape hand is not. the same with the human brain to language. this may also explain why humans are the only species known to have a handedness bias. other animals favor one limb or another, but it’s random.
“occam’s razor. the big brain is what gould termed a “spandrel”. it was not selected for directly. it results from a larger head which is selected for by cold due to allen’s rule. the brain requires a lot of blood. the head dissipates less heat when it’s larger and more spherical. a larger object has a lower surface area to its volume.”
Except human didn’t evolve in the cold, this would only apply to eskimos and neanderthal brain size.
“eskimos have larger brains than any other people. russians have larger brains than western europeans, and their heads are rounder. brain sizes have shrunk since the last glacial maximum.”
Yeah, RR has mentioned before that brain size was related to climate.
“what is more likely is that language and the human brain developed simultaneously. tom wolfe’s theory is that language is a tool. the human hand is adapted to tool use. the ape hand is not. the same with the human brain to language. this may also explain why humans are the only species known to have a handedness bias. other animals favor one limb or another, but it’s random.”
My above link from “The Conversation” shows a study that controls for language. it was shown that it helped to communicate on how to build tools, but it didn’t explain the more complex demands of toolmaking observed in different stone age periods that is likely associated with toolmaking.
What it found was an effect close to what Skoyles characterized the effect of expertise on the brain when learning to play music.
What I also read was that larger heads lead to larger cerebral arteries that helped with blood flow to the head.
Well said. I agree with everything you wrote.
John Skoyles has a paper on the evolution of language. I’m going to cover that soon. Interesting stuff.