How minimal is our intelligence?

Ur may not have been the first city, but it was the first one we know of that wasn't part of a false dawn - one whose culture and technologies did demonstrably spread to other areas. It was the flashpoint.

A contrary view — and I'm stating this deliberately rather strongly to make the point vivid:

"False dawn" is a retrospective view; which is to say an anachronistic one; which is to say a mythical one. And myths are written by the victors.

It's true that we perceive more continuity from Ur to today's civilization than from Xyz (some other ancient "dawn of civilization" point) to today. But why? Surely in part because the Sumerians and their Akkadian and Babylonian successors were good at scattering their enemies, killing their scribes, destroying their records, and stealing credit for their innovations. Just as each new civilization claimed that their god had created the world and invented morality, each claimed that their clever forefather had invented agriculture, writing, and tactics. If the Xyzzites had won, they would have done the same.

What's the evidence? Just that that's how civilizations — particularly religious empires — have generally behaved since then. The Hebrews, Catholics, and Muslims, for instance, were all at one time or another pretty big on wiping out their rivals' history and making them out to be barbaric, demonic, subhuman assholes — when they weren't just mass-murdering them. So our prior for the behavior of the Sumerians should be that they were unremarkable in this regard; they did the same wiping-out of rivals' records that the conquistadors and the Taliban did.

Today we have anti-censorship memes; the idea that anyone who would burn books is a villain and an enemy of everyone. But we also have the idea that mass censorship and extirpation of history is "Orwellian" — as if it had been invented in the '40s! This is backwards; it's anti-censorship that is the new, weird idea. Censorship is the normal behavior of normal rulers and normal priests throughout normal history.

Damnatio memoriae, censorship, burning the libraries (of Alexandria or the Yucatán), forcible conversion & assimilation — or just mass murder — are effective ways to make the other guy's civilization into a "false dawn". Since civilizations prior to widespread literacy (and many after it) routinely destroyed the records and lore of their rivals; we should expect that the first X that we have records of is quite certainly not the first X that existed, especially if its lore makes a big deal of claiming that it is.

Put another way — quite a lot of history is really a species of creationism, misrepresenting a selective process as a creative one. So we should not look to "the first city" for unique founding properties of civilization, since it wasn't the first and didn't have any; it was just the conquering power that happened to end up on top.

Also, this piece seems to be of high enough quality and of general interest that it probably makes sense to move it to main.

There is no cause to suppose, even if the human genome 100,000 years ago had the full set of IQ-related-alleles present in our genome today, that they would have developed civilisation much sooner.

The original point was not about genomes, it was about expressed IQ. Suppose the reasons for absence of the currently normal IQ in the past were environmental. If I understand correctly, your argument in particular suggests that it's the environmentally-mediated increase in IQ that might have enabled the rise of civilization (in this interglacial period). Then it's still the case that present IQ level is about as low as it can be.

The distinction your argument makes seems to be about the reason for the recent rise in IQ (environmental, not generic, at least not with changes in genes directly related to brains), not about the level of expressed IQ necessary to spark a technological civilization.

If the gene for the synthesis of docosahexaenoic acid arose 80kya, and the current interglacial period began 12kya, that still leaves four thousand years between the end of the glacial period and the beginning of city-based civilization, which, keep in mind, is a long time.

If the civilization developments followed within a hundred years or so of the necessary biological and environmental factors coming into place, I wouldn't be so skeptical that our intelligence already exceeded the minimum necessary to produce those developments. But we already had domesticated grazing animals thousands of years before the foundation of Ur, and grains earlier than that. Don't forget that when we're dealing with cultural rather than biological evolution, a millenium is no longer a relative eyeblink.

Historical quibble- in "The First City" section, you seem to be partially confusing Ur with Uruk. Uruk is generally regarded as the first city in Sumeria, during the eponymous Uruk period (4000-3100 BC). Also generally believed to be the center of the "Uruk phenomenon" during which cuneiform writing and a number of other features of Mesopotamian civilization were developed. Ur was the capital of the Neo-Sumerian Ur III empire c.2000 BC, which built the Great Ziggurat of Ur shown in the picture.

(Summary:) There is no cause to suppose, even if the human genome 100,000 years ago had the full set of IQ-related-alleles present in our genome today, that they would have developed civilisation much sooner.

(Rhetorical nitpick:) You gave an argument against one such cause. This doesn't mean there are aren't other causes, and it's not clear that your argument is decisive.

Didn't civilization develop independently in several different places, e.g. the Aztec or Inca civilizations in the Americas?

Having large mammals available to domesticate, who can provide fertiliser and traction (pulling ploughs and harrows) certainly makes things easier, but doesn't seem to have been a large factor in the timing of the rise of civilisation, or particularly dependent upon the IQ of the human species.

How would we test this? If human IQ matters, it seems like we would need some animal which is in contact with low-IQ humans and higher IQ humans, which the first couldn't tame but the second could. You already link to an example of recent man domesticating the fox, and there's quite a bit of European zebra-taming, though fully domesticating a species takes generations to breed out deleterious traits. The example of deer seems like weak support as well; some strains were somewhat domesticated by northern peoples, but that evidence is only weak to me because it's not clear the economic value of deer was the same across climates.

And it has nothing to do with the brain.

which is a fatty acid required for human brain development.

Er... what?

It seems to me that most IQ-related alleles are "build the brain this way," and so a gene that creates a necessary acid out of whatever you have lying around seems like it's an IQ-related allele. Among those with sufficient diets, there will be no effect, but among those with deficient diets, there will be a positive effect; unless the entire population has sufficient diets, that'll lead to a positive correlation.

If you're making the claim that "processing speed is not the only factor," then sure! The best example of that is neanderthals, who probably were around as good (if not better) at abstract problem-solving, foresight, tool-making, and so on, but contributed only a small percentage of genes to current humans. It's not certain why that's the case yet, but a strong partial explanation is they didn't have trade networks, and so were making the best of local materials while their competitors were able to use superior materials acquired from far away. Another good example is that developed, large civilizations moved northward with agriculture, even though there's strong evidence that IQs are higher among groups that spent significant timescales in colder (i.e. more northern) climates).

But it seems really odd to me to claim that if you dropped current humans into the world at the start of the previous interglacial period with no extral capital besides their genes, you would expect them to take twelve thousand years to reach the state of development we're at now. They've already got neat things like lactase persistence (developed 5-10k years ago), and while their adapations to modern society might be a handicap during their hunter-gatherer phase, supposing they survive it should speed up the progress of their civilization afterward.

What is the essential difference between human and animal intelligence? I don't actually think it's just a matter of degree. To put it simply, most brains are once-through machines. They take input from the senses, process it in conjunction with memories, and turn that into actions, and perhaps new memories. Their brains have lots of special-purpose optimizations for many things, and a surprising amount can be achieved like this. The brains are once-through largely because that's the fastest approach, and speed is important for many things. Human brains are still mostly once-through.

But we humans have one extra trick, which is to do with self-awareness. We can to an extent sense the output of our brains, and that output then becomes new input. This in turn leads to new output which can become input again. This apparently simple capability - forming a loop - is all that's needed to form a Turing-complete machine out of the specialized animal brain.

Without such a loop, an animal may know many things, but it will not know that it knows them. Because it isn't able to sense explicitly about it was just thinking about, it can't then start off a new thought based on the contents of the previous one.

The divide isn't absolute, I'm sure - I believe essentially all mammals have quite a bit of self-awareness, but only in humans does that facility seem to be good enough to allow the development of a chain of thought. And that small difference makes all the difference in the world.

Gwern suggested that, if it were possible for civilization to have developed when our species had a lower IQ, then we'd still be dealing with the same problems, but we'd have a lower IQ with which to tackle them. Or, to put it another way, it is unsurprising that living in a civilization has posed problems that our species finds difficult to tackle, because if we were capable of solving such problems easily, we'd probably also have been capable of developing civilization earlier than we did.

And to put it yet another way, by something like a Peter Principle ("people are promoted to their level of incompetence"), we create problems up to our capacity to deal with them. However stupid or intelligent we are, we will always be dealing with problems at the edge of what we can deal with.

This, btw, makes me sceptical about predictions of radical increases in intelligence (of us or of our creations) bringing about paradise.

Evolution, as an algorithm, is very much better as an optimizer of an existing design than it is as a creator of a new design. Optimizing the size of the brain of a creature is, for evolution, an easy problem. Making a better, more efficient brain is a much harder problem, and happens slowly, comparatively speaking.

The optimization problem is essentially a kind of budgeting problem. If I have a budget of X calories per day, I can spend it on X kilos of muscle, or Y grams of brain tissue. Both will cost me the same amount of calories, and each brings its own advantages. Since evolution is good at this kind of problem, we can expect that it will correctly find the point of tradeoff - the point where the rate of gain of advantage for additional expenditure on ANY organ in the body is exactly the same.

Putting it differently, a cow design could trade larger brain for smaller muscles, or larger muscles for smaller brain. The actual cow is found at the point where those tradeoffs are pretty much balanced.

A whale has a large brain, but it's quite small in comparison to the whale as a whole. If a whale were to double the size of its brain, it wouldn't make a huge dent in the overall calorie budget. However, evolution's balance of the whale body suggests that it wouldn't be worth it. Making a whale brain that much bigger wouldn't make the whale sufficiently better for it to cost in.

Where this argument basically leads is to turn the conventional wisdom on its head. People say that big brains are better because they are bigger. However, the argument that evolution can balance the size of body structures efficiently and quickly leads to the opposite conclusion. Modern brains are bigger because they are better. Because modern brains are better than they used to be - because evolution has managed to create better brains - it becomes more worthwhile making them bigger. Because brains are better, adding more brain gives you a bigger benefit, so the tradeoff point moves towards larger brain sizes.

Dinosaur brains were very much smaller, on the whole, than the brains of similar animals today. We can infer from this argument that this because their brains were less effective, and that in turn lowered any advantage that might have been gained from making the size of the brain larger. Consequently, dinosaurs must have been even more stupid than the small size of their brains suggests.

Although there is a nutritional argument for bigger brains in humans - the taming of fire allowed for much more efficient food usage - perhaps there is also some sense in which the human brain has recently become better, which in turn led it to become larger. Speculative, perhaps. But on the larger scale, looking at the sweeping increase in brain sizes across the whole of the geological record, the qualitative improvement in brains has to be seen in the gradual increase in size.

it is unsurprising that living in a civilization has posed problems that our species finds difficult to tackle, because if we were capable of solving such problems easily, we'd probably also have been capable of developing civilization earlier than we did.

I'd more say, it's unsurprising that life poses problems our species finds difficult to tackle, because we have moving goalposts of satisfaction in terms of our problems being solved.

http://marginalrevolution.com/marginalrevolution/2012/12/how-minimal-is-our-intelligence.html >3 comments so far.

We don't know for certain what it was about the culture surrounding the dawn of cities that made that particular combination of trade, writing, specialisation, hierarchy and religion communicable, when similar cultures from previous false dawns failed to spread. We can trace each of those elements to earlier sources, none of them were original to Ur, so perhaps it was a case of a critical mass achieving a self-sustaining reaction.

I suggest that the decisive ingredient was an explicit, somewhat accurate understanding of how children are conceived, and following from this, a concept of fatherhood.

Many hunter-gatherer societies didn't have that when we contacted them. They all had figured out it had something to do with childbearing age and menstruation. Some had narrowed it down to the pregnant woman having recently had sex with a man. But you don't need to know ejaculation inside the vagina is what counts, and that it matters who ejaculates there, unless you're trying to domesticate mammals.

From my superficial understanding of anthropology, it appears that in hunter-gatherer societies, the men have very little responsibility for the kids. Of course they contribute food and protection, which is commonly shared among the whole group including the kids. They'll teach the boys the essential skills, but any man will teach any boy the same set of skills; there's no personal connection and no specialization of labor. As a man in a hunter-gatherer society, you essentially need not worry about the next generation. And we do find that in these societies, the men (as well as the kids) tend to have a lot of spare time between hunts.

I imagine a hunter-gatherer, experimenting with domestication, first realizing he could be a father. That gives him one hell of an evolutionary advantage, and he's probably not the dumbest member of his group, so he may have good intelligence-related traits that he can now spread more effectively. But I think what's far more important is that this realization creates a lot of new priorities for him, and for everone he tells about this. Because he'd naturally start to measure his own success by the well-being of his children, much like the success of mothers was measured before. So he starts to invest much more time (both his own and the kid's) into teaching them skills that mothers can't teach because they're busy mothering. He could pass on more knowledge than a hunter-gatherer would, he'd prefer to teach his own kids over others, and boom he invents trades, family businesses, distribution of labor. Now knowledge can accumulate, inventions can be copied and spread, memetic/cultural evolution kicks in. Both the technologies that allow cities, and the refined fighting skills of the nomadic raiders, follow from intensified education.

Education increases expressed IQ. However, it also increases the value of expressed IQ in sexual selection. So I don't think we're quite as dumb as we were when civilization began. But I do think you won't find significant division of labor in any society that doesn't know about domestication of animals.

So when you ask why people accept the comparatively bad living conditions of early civilization, the answer is simple: they do it for the kids. You don't do that when you think that being a man, you can't have any.

200k years ago when Homo Sapiens first appeared, fundamental adaptability was the dominant force. The most adaptable, not the most intelligent, survived. While adaptability is a component of intelligence, intelligence is not a component of adaptability. The coincidence with the start of the ice age is consistent with this. The ice age is a relatively minor extinction event, but none the less the appearance and survival of Homo Sapiens is consistent, where less adaptable life forms did not survive.

Across the Hominidae family Homo Sapiens proved to be most adaptable. During the ice age the likely focus was simply to survive. When a temperate climate returned there are some who believe Homo Sapiens, much as future Aztecs and others, began to systematically eliminate their competition.

Concurrently, another phenomenon was occurring. Homo Sapiens was learning and steadily increasing their understanding of the world. While there is not evidence that has survived the years, it would be reasonable to posit that learning continued in much the same fashion as today; new knowledge building on established knowledge. Being less organized than later situations it would progress more slowly.

Our improved knowledge likely increased our survival rates through the second ice age. When temperate climates returned, the stage was set for the advancement of mankind to organized farming, written language and Ur.

Somewhere in this time frame, intelligence began to overtake adaptability as the dominant force. This also marked the shift from evolutionary pressure to societal pressure as the underlying force behind advancement and survivability. The random nature of evolutionary advances gave way to a more complex society-driven selection process.

It's also important to draw a subtle distinction. The advances were not a function of increase in general IQ. They were a function of integration of the concepts envisioned by a subset of high IQ individuals into society; i.e., a societal variant of evolutionary adaptability.

But they had to be free to wander to follow nomadic food sources, and they were limited by access to food that the human body could use to create Docosahexaenoic acid, which is a fatty acid required for human brain development. Originally humans got this from fish living in the lakes and rivers of central Africa. However, about 80,000 years ago, we developed a gene that let us synthesise the same acid from other sources, freeing humanity to migrate away from the wet areas, past the dry northern part, and out into the fertile crescent.

So your point is that the expressed IQ was DHA-bound for those living away from the shore, thus making them not smart enough to develop civilization where the conditions were ripe, right? Why the DHA specifically? Wouldn't there be workarounds goven that "IQ is polygenic", if the evolutionary pressure was toward higher IQ? I'm wondering if this is but one of a multitude of possible explanations, and how one would attempt to falsify it.

Yep. As I implied elsewhere, I think that the step between intelligence and civilization is an important though overlooked one in the Great Filter.

if it were possible for civilization to have developed when our species had a lower IQ, then we'd still be dealing with the same problems, but we'd have a lower IQ with which to tackle them.

On the other hand, so many of our problems are caused by other people, and some of them are caused by smart people. It took a lot of intelligence to make the financial crisis happen.

Now I'm wondering whether a more equal distribution of intelligence would lead to fewer problems.

then we might expect to see something similar to the Flynn effect.

The Flynn Effect has been an order of magnitude too fast to be accounted for by such factors.

Technologies allow more technologies to be built. For example, writing bootstraps the ability to pass on knowledge a lot. Similarly, larger populations allow a higher chance that people will make discoveries.

The toy model I sometimes use to describe this is a biased coin with a chance of turning up heads of something like 1- /(C(k +n)) where C and k and are constants, with C very small, and k very large, and n is the number of previous heads. Here a heads denotes a discovery or invention. If for example C=1 and k=10^5 then it will take a long time to get the first few coin flips but once one has a few discoveries will start to become increasingly common. C essentially denotes intelligence, so a smarter species will start getting coin flips faster.

Of course this sort of thing only works if a species has a chance at getting to civilization at all, which the vast majority don't. But it does suggest that decreased intelligence could still result in a civilization. It doesn't seem implausible that if you took out a few of the genes that occasionally come together to result in Isaac Newtons and Terry Taos, you'd still be able to get progress at a decent pace. Even Newton for example was doing stuff that was largely being investigated by other people like Leibnitz and Hooke.