In four million years of human evolution, brain size roughly tripled from 500 cm3 in Australopithecenes to 800 cm3 in Homo habilis to 1000 cm3 in Homo erectus to over 1300 cm3 in modern Homo sapiens and over 1500 cm3 in late ice age Europeans. However about 10,000 years ago, the human brain began to shrink quite precipitously only to rebound since the industrial revolution. Here’s my best attempt to show the historical trend in sex-combined Europeans, though it may need some revising:
The simplest explanation for this is the development of agriculture, as scholar Richard Lynn explains:
The period of around 25-10,000 yr ago was the last ice-age and at this time the Caucasoid peoples of Europe and the Near East had brains of approximately the same size as today (Henneberg, Budnik, Pezacka & Puch, 1985). These peoples lived largely by hunting because plant foods were unavailable for much of the year and their meat diet evidently provided them with a high standard of nutrition and enabled them to develop their large heads and brains.
Following the recession of the ice age people evolved a new life style living in permanent village settlements with domestic animals and cereal agriculture. But although the new life style was more convenient the quality of nutrition fell and many skeletal remains show signs of rickets and other malformations caused by suboptimal nutrition (Festinger, 1983).
For the last 2000 yr data on heights of adult males in Britain have been collected by Kunitz (1987) and by Floud, Gregory and Wachter (1988). The broad trend is that height has been constant at a mean of approx. 172 cm up to the cohort born around 1930. From this date onwards height has increased. It seems reasonable to infer that brain size and intelligence were approximately stable for about 2000 yr up to around 1930 and it is only in the last half century that the increases have occurred. In the economically advanced nations the improvements in nutrition have enabled us to recover the brain size and intelligence levels of our ancestors of 25,000 yr ago.
Of course this analysis ignores long term secular changes which may have taken place in the genetic and cognitive stimulation determinants of intelligence, but is nevertheless offered as an approach to the intriguing question of long term historical trends in intelligence.
As usual, Lynn provides the most parsimonious explanation. Of course not everyone agrees that agriculture was the cause of falling brain size, because brains shrunk even in sub-Saharan Africa and Australia where agriculture arrived late. While it’s true Australian aboriginals had much bigger brains 10,000 years ago than they do today, there’s seemingly no evidence that their brains shrunk prior to European colonization and the resulting change in diet and life style. Meanwhile the chart below shows little evidence that brain size in Africa shrunk prior to the arrival of agriculture there, several thousand years ago.
Thus I think brains shrunk because of malnutrition and disease (agriculture) and not because of backwards evolution. Of course with the end of the ice age, intelligence was not as crucial to survival (even in the tropics where it caused drought) so that may have relaxed selection for higher IQs, creating a dysgenic effect. Also, a warming climate selects against brain size because a big head overheats like a 100 watt light bulb. However ice ages have ended before and brains did not shrink. What was different the last time? Agriculture.
Pumpkin Person 
“Thus I think brains shrunk because of malnutrition and disease (agriculture) and not because of backwards evolution. Of course with the end of the ice age, intelligence was not as crucial to survival (even in the tropics where it caused drought) so that may have relaxed selection for higher IQs, creating a dysgenic effect. Also, a warming climate selects against brain size because a big head overheats like a 100 watt light bulb. However ice ages have ended before and brains did not shrink. What was different the last time? Agriculture.”
I would love to see these primary sources. I already ordered the Festinger book and will post on it when I read it. PP, agriculture didn’t make it to southern Africa and Australia until modern times and brain size has been decreasing there as well. So it’s not agriculture. This is almost like the alternative hypothesis’s argument.
Again, I see the logic. If you think about it, if you’re eating a plant-based diet then there is a great chance for malnourishment. However, hunting was still occurring then. Plant-based diets are fine in comparison to others if you know what to eat and supplement. However this is a bad explanation for this.
I’d like if you’d cite the primary references instead of citing Richard Lynn, as short explanations don’t really say too much. So yea it’s not agriculture.
Also it’s extremely important to note–correlation doesn’t equal causation. I agree with Santo here that it’s due to “domestication”–ie being on modern societies that have shrunk our brains. Yes, agriculture allowed the beginning of modern society, but that wasn’t the cause of the brain size decrease. Due to us being close knit and working together, we didn’t need as much cognitive power as we have others to piggyback off of. This in turn lead to the decrease, agriculture is just a correlation, nor cause.
I haven’t finished reading The Ten Thousand Year Explosion yet, so I may be wrong and maybe Cochran and Harpending say otherwise with some causal data. J double the I’m wrong though.
That’s possible, but the fact that brain size and height have suddenly rebounded to stone age levels suggests the explanation is environmental, not genetic
“That’s possible, but the fact that brain size and height have suddenly rebounded to stone age levels suggests the explanation is environmental, not genetic”
There’s a good chance that it’s not fully environmental though. Santo’s explanation is great here. If you think about when modern-like behavior appeared in humans then think about the decrease in brain size, I believe that cooperating with others is a huge cause of that decrease. Because as I said, we didn’t need as much cognitive power since we had a whole group to piggyback off of.
“But I see no evidence the decrease started BEFORE agriculture or in the case of Australia, being colonized by agriculturalists.”
I’ll provide sources later.
“And when Lynn says agriculture, he also means all the diseases that came from farming which brought humans and animals together and the subsequent cities which brought huge populations together spreading more disease. Disease prevents the body from using nutrients, so that too was an indirect effect of agriculture.”
I agree. However, again that’s not a cause, just correlation. For example some researchers say for Africans that if and when parasitic load and disease go away we should monitor them for IQ gains and if they increase then that was the casual effect. How could we measure the same in humans? Looking at Hunter gatherers and their brain size?
“If not agriculture, then what explains the shrinking brains?”
This is admittedly speculative and I’m piggybacking off Santo:
Cooperation in modern like someone’s caused the decrease and due to their didn’t need as much cognitive power to survive as we had the group who had our backs. Agriculture is interesting, but I won’t say it’s definite until we provide causality.
I don’t have as much problem with this hypothesis as the more evolved hypothesis.
So long as you’re not saying that different races evolved to digest carbs differently!!
I’ll return to this in full after I read Festinger 1983.
PP, agriculture didn’t make it to southern Africa and Australia until modern times and brain size has been decreasing there as well.
But I see no evidence the decrease started BEFORE agriculture or in the case of Australia, being colonized by agriculturalists.
And when Lynn says agriculture, he also means all the diseases that came from farming which brought humans and animals together and the subsequent cities which brought huge populations together spreading more disease. Disease prevents the body from using nutrients, so that too was an indirect effect of agriculture.
If not agriculture, then what explains the shrinking brains?
PP I just got to a part in the book I’m reading about human evolution, disease and nutrition about agriculture. It’s a great read and I’ll be done with this section tonight and be able to give my thoughts and the sources that Lieberman uses.
Civilization need conformity. Usually bigger brains as well stronger personalities may correlates with lack of conformity.
Social conformity shrink the brains, my opinion, but human domestication is not as linearly ”perfect” as in dogs.
Civilization started to select a predominance of servile-mind people.
Agriculture was important aspect to create a civilization, a bigger sedentary conurbed communities.
Well said. I agree.
PP you’re right that all these diseases popped up after agriculture. I recommend you look into “diseases of civilization”. Hunter gatherers have almost nonexistent rates of heart disease, type 2 diabetes and so on. But that’s, mostly, due to them not eating processed foodstuffs. After the introduction of food processing (the whiter a food is after processing the more processing was done to it and it has less overall nutrients and protein as well as fiber, which is a natural protectant against obesity) is when these diseases saw a huge uptick. Processed carbohydrates and foods are the cause for our obesity epidemic as well as a surplus in foods. I’d like to see you do a post on that one day as well.
One more important point PumpkinPerson: we didn’t evolve to be healthy. Because natural selection favored fertility over health. A good example is paleolithic hunter gatherers. Since they faced periodic levels of food shortage and rented to be physically active, they were selected to want energy-rich foods and rested whenever possible which helped them to store fat and devote more energy to reproduction. Looking at dieting from an evolutionary perspective, this is why they’re doomed to fail. So yes, effects from our hunter gatherer ancestors still persist today and, much to the chagrin of people who hate fat people (idiotic), there are huge evolutionary reasons why we seek out calorie rich foods, and a huge reason WHY we get fat.
I thought humans are becoming fatter because extreme sedentary way of life (our body are programmed to be in constant movement) and very trash (very excessive) food, specially the processed ones. No surprise is in America we have a explosion of obesity. No surprise, a overwhelming thinner people like chineses started to become fatter.
this epidemy of obesity is very recent at least in the last two centuries. I no doubt if the last romans had fattened because the prosperity of the roman empire.
”Because natural selection favored fertility over health.”
I don’t know if i agree or disagree with you…
i thought in the natural scenarios fertility follows health. Organically disordered individuals have little chance to survive in natural scenarios and among non-human species, so their fertility rates tend to be extremely lower.
”health” in natural scenarios generally mean ”fit with ‘environment’ ” and seems indissociable with ”have a balanced organism”.
Santo, not really. Becoming sedentary has lead to huge diseases, but exercise doesn’t induce weight loss.
http://nymag.com/news/sports/38001/
Well, you didn’t need to be fully “healthy” to pass your genes, just had to be “good enough”. Thus, NS didn’t select for healthy but fertility and as I’ve been saying, fertility is linked to environment.
”These peoples lived largely by hunting because plant foods were unavailable for much of the year and their meat diet evidently provided them with a high standard of nutrition and enabled them to develop their large heads and brains”
Garbage!!!
correlation, not causation, Lynn chink-lover!!!
Cold theory or cook-meat that increase human brain size** 😉
It was a mix of the two.
Santo there is good data to show that cooking lead to an increase in brain size. Look at brain size with homo erectus than after cooking meat was invented, it’s a good correlation.
The correlation don’t equal causation here is the fact that I’ve yet to see causal information, this is a correlation not causation argument.
PP is right here that cookie meat lead to bigger brains and skulls. Much has been written on this in the past 10 years.
Coincidence…
when humans started to think via more scientific way they found how cook their food.
near to impossible a human with no complex thinking found a way to cook their food.
they need collect tree branches, pay attention to the wind direction, organize the branches, dominate the fire… in other words, behave like a modern human.
And, hunt is more cognitively exigent than ”just” collect fruits in trees, of course, based on that pre-historic scenario.
in the natural world, worst environment select more, more faster and directional than in the ”more easy” environments, to live.
PP, Jared Diamond agrees:
http://www.ditext.com/diamond/mistake.html
He calls farming “the worst mistake in the history of the human race”.
Of course he says that farming lead to muh human inequalities and muh class divides, typical Marxist. It also lead to capitalism in contrast to how we used to live in small communist, egalitarian bands!!! Oy gevalt!! Agriculture is the cause for human inequality!!
I hate Marxist interpretations.
An dog course agriculture was bad for health; when you learn the effects of processed carbohydrates on the body and insulin’s physiologic effects on fat gain and fat storage then you’d understand why it’s processed foodstuffs that has lead to our current “diseases of civilization”, not directly a result of farming itself. A correlation, but not cause. The cause is processed foods. Mostly high GI carbs.
”Epidemics couldn’t take hold when populations were scattered in small bands that constantly shifted camp. Tuberculosis and diarrheal disease had to await the rise of farming, measles and bubonic plague the appearnce of large cities”
Urban plagues in antiquity like black death seems was caused by complete lack of basic sanitation/bad to horrible habits, overpopulation of urban rodents, lack of basic first aid in case of infectious disease (many people sought the knowledge of the church to cure)… and many people were malnourished in the european middle ages… and not exactly because greater demographic aglomerations.
In the true, it’s not bad at all live near to many and diverse people… amerindians and other isolated groups agree with me, 😉
And because bubonic pest was brought by Sicilians, the first documented cases of plague in Europe were reported in southern Italy.
That’s what I read in a famous book of universal encyclopaedia of the Times
Before smash with Europe, the Black Death had devasted large regions of asian continent.
”Of course he says that farming lead to muh human inequalities and muh class divides, typical Marxist”
Social justice existed before marxism.
Agriculture was the mother fucker of (less primary type of) capitalism we know…
Just finished the section. Some thoughts.
It seems there is both good and bad from agriculture. Did increased population size lead to agriculture or did agriculture lead to increased population size? As you said last week I believe, bigger populations are better disease vectors. So when agriculture formed, infectious diseases took hold, which didn’t occur in hunter gatherers due to their small population size, around 1 person per sq km.
Moreover, the biggest change from agriculture was, as I’ve been saying for months and have documented on my blog, processed carbs. Now, hunter gatherers do have lower rates of “diseases of civilization”, low to almost nonexistent rates of heart disease, type 2 diabetes, and other modern diseases. The obesity epidemic seems directly from processed carbohydrates which spike insulin. Look what insulin does to the body.
Insulin inhibits the breakdown of fat in the adipose tissue by inhibiting the lipase that hydrolyzes (the chemical breakdown of a compound due to a reaction with water) the fat out of the cell. Since insulin facilitates the entry of glucose into the cell, when this occurs, the glucose is synthesized into glycerol. Along with the fatty acids in the liver, they both are synthesized into triglycerides in the liver. Due to these mechanisms, insulin is directly involved with the shuttling of more fat into the adipocyte. Since insulin has this effect on fat metabolism in the body, it has a fat-sparing effect. Insulin drives most cells to prefer carbohydrates for energy. Putting it all together, insulin indirectly stimulates the accumulation of fat into the adipose tissue.
http://arbl.cvmbs.colostate.edu/hbooks/pathphys/endocrine/pancreas/insulin_phys.html
With processing food, which began shortly after agriculture, this lead to higher insulin levels due to refined carbohydrates which lead to more diseases and higher rates of obesity (this is where idiotic people who hate fat people have things confused; obesity doesn’t cause the diseases that are normally attributes to obesity, the diseases normally attributed to obesity cause obesity.
Some people are scared that we will keep getting fatter and fatter until we reach a point where all people are fat due to our modern environment which is an “obesogenic environment”.
https://www.ncbi.nlm.nih.gov/pubmed/17152319
But our obesogenic environment is a cause of refined carbs which is cause of agriculture. So I do agree with you. I’m so stupid that I forgot what I read in Gary Taubes’s book, Good Calories, Bad Calories, that hunter gatherers have low to no rates of these “diseases of civilization”. I’ll write a post on that this week.
But it stands to reason that individually the variation of carb digestion is greater than in between races and ethnies, so as I showed in my refutation of the alternative hypothesis garbage article (seriously if you’re clueless about nutrition and what different micros and macros do in the body, don’t write about it or make a video on it).
So yea pp I do half way agree with you, and Diamond as well (his Marxist garbage aside about muh hierarchies et al) that farming was a negative, but there are still positives. But mostly negatives. For instance negative ‘mismatch’ effects. Since farming exploded the population, obviously more people were around for selection. Natural selection can only select for gene variants that are currently in that population. There are hundreds of regions of the genome under selective pressure since the dawn of agriculture.
I’ll piggyback off you later this week and write a nice post about the “diseases of civilization”.
”It seems there is both good and bad from agriculture. Did increased population size lead to agriculture or did agriculture lead to increased population size? As you said last week I believe, bigger populations are better disease vectors. So when agriculture formed, infectious diseases took hold, which didn’t occur in hunter gatherers due to their small population size, around 1 person per sq km”
This part was directed to me*
If it was, bigger population is not better vectors per se, but because generally bigger population mean: greater territory, social inequalities that cause endemic infectious disease among lower classes, mostly, bad habits for example in the treatment of ”meat” and other food as well natural relaxation of the selective pressures that make health less significatively important to be selected.
The best ”vector” factor to spread a infectious disease generally and naturally speaking (without into account social factos like poverty) is genetic homogeneity, as well a vulnerability to the certain disease, and also possibly, geographical isolation.
Bigger populations and rampant poverty or social inequalities are the best formule to create a fertile environment to the fabric of the new infectious diseases.
But a little group of isolated and genetically similar people, seems, more vulnerable to be collectively and or massively killed by new diseases, even without any decisive socio-economic factors influencing in this malignant dynamics.
it seems possible that the fall in brain size is due entirely to the replacement of hunting/gathering with farming, just like height and life expectancy fell with the adoption of agriculture.
but i thought contemporary europeans had significantly smaller brains than paleolithic europeans.
hence some anthropologists contend we are all now living in Idiocracy.
but i thought contemporary europeans had significantly smaller brains than paleolithic europeans.
Most anthropologists are unaware that brain size has increased since the 1930s just as height has, so they assume our brains today are way smaller than in Paleolithic times.
However Richard Lynn argued brain size exploded since the 1930s based on the trends in adult height & baby head circumference
But it’s hard to get comparable data because you can’t full the
Skull of a living person’s head with mustard seed & attempts to estimate cranial capacity by external measures can give wildly different results
“near to impossible a human with no complex thinking found a way to cook their food’
One “smart” individual after pigging out on smoked meat after a lighting induced prairie fire, ” Mmmm, finger licking good, me open Arby’s.”
I wish everybody wouldn’t dis Marxists all the time. At the very least you could give trigger warnings. It can be hurtful.
Pelvises.
Up until recently, human brain size was highly limited by human pelvis size–babies with too-large brains killed their mothers and then died. Today we have cesarian sections, so large-brained infants and mothers survive.
Disease, malnutrition, and famine–all common side effects of agriculture–increase chances of rickets, other bone diseases, and narrowed pelvises, placing a practical upward limit on the number of big-brained babies a population can give birth to.
I’m doing my part for eugenics. I have always loved women with the widest hips.
Women with narrow hips hips look boyish.
”I’m doing my part for eugenics.”
fear##
This is for Santo:
https://www.conquerclub.com/forum/viewtopic.php?f=8&t=219270&sid=f0ac2d7e7838a66e2c50f1615ccd079c&start=25
It seems like a Frenchman has a hard time explaining to the Chinese, that he enjoys life by working less and being an intellectual. Bureaucratic Chinese people of course, do not understand this. Worse, they work harder than Westerners, and cannot even surpass us in human progress. Chinese are too stupid to realize that machines will replace them in the near future. Robot drones will replace human drones.
JS,
if chineses ”were” on avg such a creative and reflective people like in their long past, now, ”they” aren’t anymore… but remember, most of the french intellectuals are socialists or any other post-modern breed, not so good…
Westerners are more successful and wealthier on average, because they are a lot more dynamic, original and risk taking than the Chinese. In America, East Asians have higher incomes than the average Whites, but not of the elites. Furthermore, Europeans live better than most of East Asia.
JS is full of shit.
there are lots of chink billionaires in china…aka chinkistan.
”I’m doing my part for eugenics.”
fear##
Not me dickhead. The wide pelvis women for the big headed babies.
Do your part as always and keep taking it up the ass.
I fully remember about your person Iffen, so deplorable…
you’re one of this commenters in this blog that time or another appear here JUST to say that ” you’re contributing because children had ” high iq ”.
Typical IQdiot …
humanity is a variety of … full retards of all kinds and colors.
The best contribution that you could do is to sterilize yourself, but it is too dumb to know about yourself.
Your level: arrogance + non-existent self knowledge, is almost the same as a leftist dumb. The difference is that you are ” conservative ”.
The poverty soul is the same.
” you’re contributing because you have ”higher IQ” kids”
”big head” babies, but you’re a prole, do you knew it**
PP I concede I was wrong about half of what I said about agriculture. I’m an idiot, I forgot what I’ve read about Hunter gatherers and their rate of disease acquisition. I’ll make an extensive post on rates if disease for Hunter gatherers eventually, I know a great source for that.
Do you agree with Jared Diamond that farming “was one of the worst mistakes humanity has ever made”?
He, of course, only said that because of his political ideology. And of course used his class struggle Marxist talking points. Other than that I do agree. Because agriculture lead to food processing which lead to refined carbs which spike our insulin more and cause obesity.
I also just read that the way we sleep isn’t natural compared to how we used to sleep. Sleeping in quiet rooms isn’t how we fell asleep thousands of years ago. So this scores up our sleep patterns, which exacerbates obesity even more.
But yea you’re right. I completely forgot about the data on Hunter gatherers and disease acquisition (not conceding on the other thing though, that’s our ongoing debate. =^) )
It’s also the contrarian in me that Iove arguing and nitpicking things to discuss them to better strengthen my own and other’s arguments (especially someone on my side).
Electricity also contributed to make people sleep later in the night resulting in higher levels of anxiety and nocturne attacks on refrigerators.
Here’s an interesting paper arguing that c-sections are driving the evolution of big brains because babes will survive that wouldn’t have normally without intervention. Good read.
Neonatal size and maternal pelvic dimensions influence fitness (i.e., reproductive success) of the newborn and the mother in multiple ways. Undoubtedly, relative brain size had increased during human evolution in response to directional selection. Recently, it has also been suggested that the large human brain may be the result of runaway selection for the childcare of infants that are born prematurely because of their large brain (12). It is unclear whether any of this selection still persists after the slight decrease of brain size in the late Pleistocene. However, birth weight, which correlates with brain size at birth, is strongly positively associated with infant survival rate (13) and has also been reported to correlate negatively with the risk of multiple diseases (14). Reducing neonatal brain size by shortening gestation length seems to be equally disadvantageous: Delivery before term clearly increases the likelihood of impaired cognitive function in later life (15, 16). Grabowski and Roseman (17) identified a complex pattern of natural selection that has acted on the pelvis throughout hominin evolution, but no consensus has been reached about the actual benefit of a narrow pelvis for bipedal locomotion (7, 8, 10, 11). However, a narrow pelvic cavity might be advantageous for other reasons as well.
Click to access 1612410113.full.pdf
Black and Asian (probably all of Asia) women have more c-sections.
http://bmcpregnancychildbirth.biomedcentral.com/articles/10.1186/1471-2393-13-168
Thoughts?