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Comment by witherk | Hacker News Reader

Modern humans in the developed world have access to insane quantities of calories. Too bad that evolution is still scared of us starving to death so we store the calories as fat. I think over evolutionary time, our brains could do some unbelievable things using all those calories.

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In Alastair Reynold's https://en.wikipedia.org/wiki/Revelation_Space_universe there is a genetically and cybernetically engineered subspecies of humans called Conjoiners who do just that. They take it to such an extreme that they eventually need to engineer their skulls to grow heat-dissipating fins, because otherwise their brains would cook from the waste heat.

I think the brain might be thermally limited so adding more fuel to the fire could only do so much. Maybe future humans will have to take up a lot more copper to deposit in the cooling veins.

If you beat the heart a lot faster you probably get pretty good cooling. Vent that in the extremities and start sweating. There is obviously still a limit but in day-to-day life we don't even really come close to the brain's cooling capacity.

Well your comment is typical to the bias “all calories are equals”

First, all calories are not equals, therefore you can be starving and pushed to store energy, in an abundant calories intake.

What matters here is bio availability or nutrient in the calories intake. If for instance your protein intake is too low, and available vitamins is poor, whatever the amount of “energy” ingested this will trigger starvation mode and energy saving. Have you ever read scientific littérature about how hybernation is dietetary induced in hibernating mammals? As shift of diet to high sugar, high seed oil (from grain) greatly available during summer (weight increase period for hibernating mammals) by lowering metabolism rate, promoting fat storage and torpor.

In early 19th, average calories intake of French and Switzerland was around 4000 to 4500 kcal a day, without obesity crisis while in the same time in American states adopting seed oils emerging products while the daily calories intake was half those amount, overweight appeared and started to spread.

So no, calories in calories out, and all calories are equal, are not true and therefore cannot be used at any prémisses of rational development.

Probably not by natural pressures, though. We're more than intelligent enough to outcompete any species that might try to fill the same ecological niche as humanity. No benefit to even more brain power. It would more likely take intentional selective breeding if we wanted to go that route.

Most evolutionary progress comes from outcompeting inferior members of your own species, not others. But it's also true that in modern society, intelligence doesn't seem to confer reproductive fitness.

That's an interesting idea. Do we know what is different about the brains of geniuses that could be replicated by changing how the brain grows or consumes fuel in a normal pereson? I know descriptions of "high-IQ" and "normal" are extreme simplifications of a complex, multidimensional concepts, but I have to imagine someone like John Von Neumann who apparently never forgot anything he read, has had to have had something physically different in his brain.

For example, do we know if high IQ/abilities are associated with more neural connections in the same brain volume?

Not really answering your question, but many Nobel-prize winner people were of Ashkenazi origin, who have some genetic changes that can cause serious neural problems, but at the same time these genes may be responsible in part to their genius.

The other kinda dumb constraint is that our heads are roughly as large as they can be and still survive vaginal delivery.

Evolution got around that by birthing what are essentially still fetuses compared to most other non-marsupial mammalian newborns and then continuing the base development process of the brain after birth. See how a lot of other newborn animals are already walking around just minutes after being born.

Eyeballing based on my children development against other mammals, I’d say pregnancy should take about 2 years.

A lot of animals come out walking! Imagine squeezing out a 30 something pound walking toddler!

Caesarean-section removed this constraint. Since it was introduced, the number of births requiring a C-section due to size have increased:

https://www.bbc.com/news/science-environment-38210837

> number of births requiring a C-section

Slippery metric. "Requiring" seems hard to isolate vs other options like "elected to use".

Yeah. If there's an evolutionary aspect to the increase, we should expect to see c-sections as a generational phenomena, and correlated with cranium size. I wonder if that study has been done.

>... other options like "elected to use"...

Supposedly more common as a choice amongst higher income women. Hence the phrase "Too posh to push"

is it dumb?

I admittedly havent spent much time thinking about the problem, but it seems to me that the issue of getting one human out of another human is quite a difficult problem to solve.

doesn't birthrate correlate with lower IQ though? so there isn't really any evolutionary pressure at present for this to happen.

This sounds as if people in the less developed world are somehow mentally challenged. What an odd comment tbh.

Not how I read it. Thought they were saying that our brains could evolve to use more calories since they are abundant now, instead of storing the calories as fat as our bodies currently do. Basically what if you could make your brain 50% more powerful at the expense of needing more calories, it would seem like a pretty good trade off today since many of us eat more calories than we need anyway.

Energy budget of brain compared to rest of the body is already very substantial I wonder if we would face some issues if it was higher. Like maybe overheating.

I'm willing to install a water cooling system if it means I can OC my brain.

A good point. Incidentally i need to eat like a whale despite sitting on a chair all day long. Brainpower is a hungry business but i dont get it my body needs to store some of that food as fat. I eat all day long! Perhaps we are feeding it the wrong stuff and what we are used to eating is no longer suitable for how we use our bodies in the modern day? But what about the super developed countries of east asia where people appear to be skinny? Is there something wrong with our diet in the european and american world?

Other than genetics I'm pretty sure there's a lot of things that make people less hungry.

I've heard sugar makes people want to eat more. I'm pretty sedentary, so when I cut back on sugar, I can easily just kind of forget to eat.

Evolution doesn't know about fridges and thinks people still need to store energy, like as if we are going to walk 10 miles after a day long fast at any moment. So many constraints no longer exists, seems like we should definitely be able to eat better than before.

Who knows how many things no longer apply to most people. Maybe some foods enhanced fertility and that preference was selected for, but most people don't need them now. Maybe some things helped people heal from specific blunt trauma injuries that are now rare, but at the cost of causing some extra heart disease.

Almost every overweight person could kick my ass just by falling on me. They can probably lift more than me. Many would do 200% better in the wild than me, but statistically they are at risk for heart problems and many already have assorted aches and pains.

The whole concept of health in popular culture is way too tied to strength and survival and naturalness. Why do we seem to pay more attention to who can climb a mountain and lift 400lbs than we do to which populations live the longest and have the least illnesses?

Although this sounds like a good idea for an individual, there’s really no point, because a group of well educated humans focused on a specific goal can easily have far more brain power than a single individual, and with far great redundancy. Therefore making one single individual far more intelligent and powerful at thinking has little use to society, unless they are focused on tasks that inherently can only be done effectively by a single individual, and which are becoming fewer as our tools for collaboration grow. It’s cool to have someone be like an Einstein figure, but Einstein alone could never match the combined brainpower and output of NASA for instance.

Hmm, I don't agree because I don't think intelligence scales out like that. Certainly a group of people can do more than a single person but I personally think things like increasing a persons short term memory could have pretty profound impact on our ability to have bigger ideas simply because you could hold more things in your head at once for example.

I think you're reading it wrong: GP is saying if the brain could use as many calories as were available, then people with access to fewer calories would be at a handicap; but such is not the case.

I stand corrected.

To be blunt, yes. People with poor nutrition, particularly in childhood, experience both physical and mental stunting, some of which is irreversible. Certain diseases which have been curtailed or eradicated in developed countries inflict a similar toll.

I'll give a concrete example that combines both effects. Hookworm is an intestinal parasite that causes nutritional deficiencies in the host. Children with hookworm are impaired across the board, mentally and physically. They can't run as fast or read as well as their hookworm-free peers. If we compare two otherwise comparable populations, one with hookworm and one without, we would expect the hookworm-infected population to be less intelligent on average.

I'm not saying this to look down on anyone. Human populations always show enormous variation, anyway, so it says nothing much about any individual. But that burden, of physical and mental impairment and chronic illness, due to poor nutrition and infection, is a significant barrier to development, and a major part of why parts of the less developed world remain less developed. And it's why I believe childhood vaccination, disease eradication and nutrition programs in poorer countries are some of the best things we could spend our resources on, in terms of furthering human development.

>To be blunt, yes. People with poor nutrition, particularly in childhood, experience both physical and mental stunting, some of which is irreversible.

I don't disagree, but I was trying to substantiate this point once and I couldn't find any one good source that would confirm such a statement. Would you mind sharing a reference to some good source material approving the conjecture that poor nutrition in the childhood causes mental and physical stunting?

This study [1] deals specifically with brain imaging in the malnourished, but it starts off with a pretty good literature review in section 1 and 2 that may offer you some pointers. This [2] is a review of the literature on the question of childhood nutrition and brain development, see particularly the section "long-term consequences of undernutrition in early life":

> Many studies have compared school-age children who had suffered from an episode of severe acute malnutrition in the first few years of life to matched controls or siblings who had not. These studies generally showed that those who had suffered from early malnutrition had poorer IQ levels, cognitive function, and school achievement, as well as greater behavioral problems. [...]

> Chronic malnutrition, as measured by physical growth that is far below average for a child's age, is also associated with reduced cognitive and motor development. From the first year of life through school age, children who are short for their age (stunted) or underweight for their age score lower than their normal-sized peers (on average) in cognitive and motor tasks and in school achievement. Longitudinal studies that have followed children from infancy throughout childhood have also consistently shown that children who became stunted (height for age < −2 SD below norm values) before 2 years of age continued to show deficits in cognition and school achievement from the age of 5 years to adolescence.

[1] https://www.sciencedirect.com/science/article/pii/S105381192...

[2] https://academic.oup.com/nutritionreviews/article/72/4/267/1...

This is just one of the many ways of "proving" that people in developing nations are somehow inferior. The same people that grew up with poor nutrition perform quite well when relocated to other countries. While in developed regions there are people with access to food yet dumb like a kite. I think we should be careful with the conclusions we draw. Certainly nutrition, let alone disease or parasites, can lead to reduced mental performance, but deriving the fact that the developing world is somehow suffering from reduced mental power, because of food, as a whole is wrong and in my view dangerous.

A nice thing about the hookworm example is it applies within the United States. It was common historically in the South, but not the North. This may well account for some of the stereotypes about the lazy, stupid Southerner, as well as the gap in economic development and educational attainment. [1]

> How much credit, if any, hookworms can take for those lingering economic challenges and misconceptions, however, is nearly impossible to measure, although some have tried. Hoyt Bleakley, an associate professor of economics at the University of Michigan, used early to mid-20 th century census data and records from the Rockefeller Sanitary Commission to compare educational and economic gains in places where hookworm eradication did and did not take place. He found an increase in school attendance and literacy in relation to hookworm reduction and also discovered that those effects seemed to extend into adulthood, with better-educated children growing up to be higher-earning adults. This suggests, Bleakley writes , “that hookworm played a major role in the South’s lagging behind the rest of the country.”

> “If you compare places in the South with the worst versus the least hookworm problem, you’re talking differences in income of maybe 25%,” he says. “There are lots of reasons why the South had a different developmental path than the rest of the country, and while disease is not the whole story, it was certainly part of it.”

[1] https://www.pbs.org/wgbh/nova/article/how-a-worm-gave-the-so...

Is it so wild to generalize this to the rest of the world?

Generalising about the south in the us is as wrong as generalising about the rest of the world.

Incidentally in most european countries you find jokes about the south of the same countries as in the us. Its just something we do with people far and different we look at their ways and call them dumb.

The article tho has made an attempt at proving it with science. Correlation does not imply causation.

You cant simply draw the conclusion that a mass of people are dumb and then make up the science to prove it. Sure there individual and small localised groups affected by it but not whole nations or even massive areas of a country.

Edit: even here on this forum, there is anecdata from people that grew up in poverty with little to eat or poor nutrition yet they perform well given the opportunity. Some from the west, some from asia.

Anecdata can be a distraction from general principles.

There are disabled people who climbed Mount Everest, but that does not mean that disability is irrelevant for your chances.

> There are disabled people who climbed Mount Everest, but that does not mean that disability is irrelevant for your chances.

More accurately, there are disabled people who have had sherpas drag them up Mount Everest. To be fair, that's what most so-called mountaineers do these days.

It's interesting, because in Germany the southerners are observably much more technically accomplished than the northerners. But there's still that you don't speak High German prejudice.

You hardly address his point.

You say:

> While in developed regions there are people with access to food yet dumb like a kite.

But he explicitly said:

> > I'm not saying this to look down on anyone. Human populations always show enormous variation, anyway, so it says nothing much about any individual.

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