The shape is perceptibly different from a Gaussian (at least in the distributions that I found googling “empirical distribution of IQ” and similar keywords). This is not surprising, because almost nothing in Nature is an ideal Gaussian.
Thank you, I will look at the paper.
Now, suppose everyone began gaming the “athletic ability” test so that the table of maximum speeds B in light of scores didn’t correlate anymore, what would happen? Well, psychologists would analyze the new trend. They’d look at current full time professional short range runners, the scores they obtained in their “athletic ability” test when they took it a few years before, and develop a new table with updated maximum speeds B for “athletic score” abilities, so that both numbers began correlating again.
Here you are supposing that everyone does the same amount of preparation; otherwise, recalibrating the score would not be enough. I think that this is the main point: does everyone prepare the same amount for IQ tests?
(A) and (B) make different predictions. If (B) is true, people with high IQ will not be particularly good at a new task when they try it for the first time—but then they would improve by application. If (A) is true, people with high IQ will be immediately good at new cognitive tasks (or, at least, much better than people with low IQ).
Thank you for your answer!
If you practice for IQ tests, you’re going to become better at detecting the specific kinds of patterns used in IQ tests, but then your IQ score will correlate less with your general pattern-recognition ability, and in turn with those other traits, so at some point your score will stop reflecting your general intelligence. [...]
Are you sure of this? Maybe the sort of people who are motivated to get an high score in a IQ test are the same sort of people who are motivated to get good grades in the college, who work harder to advance their career, and so on.
To clarify, we have two possible explainations for the correlation:
A) People with a high IQ score got their high IQ score because they have a better innate capacity to detect patterns, so they are also innately more capable to become engineers or lawyers. People with a low IQ score have a low innate intelligence, so they are not able to understand that being a criminal is a bad idea.
B) People with a high IQ score got their high IQ score because they were motivated to get an high IQ score. They are also more likely to become engineers or lawyers, because they are motivated to work hard to achieve their goals. People with a low IQ score just wanted to finish this boring test as soon as possible, so they gave random answers and returned to bar drinking.
I think that a mixture of (A) and (B) may be true. Most of your answers suggest that (A) is the most relevant explanation. However, if you for example replace “IQ score” with “school grades”, I would say intuitively that (B) is the main answer. Is the IQ test fundamentally different from a school test?
I agree that different peoples have different learning curve.
I wonder if perhaps a more appropriate test of “general intelligence” (+ motivation/grit) would be assessing how much you are able to improve in a task, given 1 month to practice.
Probably it is hard to make this work, because you could cheat in the first test doing it terribly on purpose.
Thank you for your answer, however, the question is not if it is worthy, or useful to practice for IQ test; the question is if it can be done (and, secondarily, how many people do it).
Usually, the ranking of abilities for a task are well correlated with the amount of practice. There is the rare child prodigy who beats the chess grandmaster, but usually all the people who can beat a chess grandmaster have practiced a lot of chess.
Is IQ special in this respect? Is the majority of people who is extremely good at IQ tests just “naturally” extremely good at IQ tests?
The mean IQ is different among different cultures in the United States. Could these differences be explained (at least partially) by different mean levels of preparation? For example, I imagine that if you grow up in a highly competitive culture, and your family presses you hard to achieve good grades, you will more likely also study more for an IQ test.
Maybe I am in the minority, but I think that I in my teenage years I would definetely have studied for an IQ test if I had had to take one.
Let us say that only 1% of people are like me, and the other 99% does not care. With your premises, that 1% would get a very high IQ. This is still a lot of people; is it possible that they are the majority of the people with high IQ? Or do you think that most of the people with IQ > 130 are “natural” (in the sense that scored high without solved made similar exercises before)?
Interesting, can you direct me to some scientific papers which prove conclusions (1) and (3)?
(I already believe (2))
Thank you for your reply! The differences in economic developement are undoubtedly a part of the story; it is hard to isolate the “material culture” from the rest of the culture. I never said it has to be direct cultural transmission (expecially in the case of Poland, which was resettled by colonists from all the other areas of Poland. Barely one sixth of the population of Western Poland in 1950 was made of Germans who inhabited in the same place in 1939; is it enough to have direct cultural transmission? Maybe, but the quick resettlement itself may have been a cause of cultural divergence).
The economy and the environment shape the culture, but sometimes also the opposite is true (you can tell which is the border between Dominican Republic and Haiti simply by looking at Google Earth). Emilia-Romagna and Lombardy/Veneto are two sides of the same Po Valley, and as far as I know have similar densities of small manifactures: so yes, maybe the former border is a part of the explaination for the fact that they have ended up opposing each other politically.
The immediate cause for the fact that “lead pollution in 200 AD was lower than lead pollution in 1 AD” is that “the extraction from Rio Tinto mines in 200 AD was lower than the extraction from Rio Tinto mines in 1 AD”. Now, according to Diodorus Siculus (Bibliotheca historica, V, xxxvi-xxxvi), the Carthaginians used mechanical and hydraulic technology for exploiting the Rio Tinto mines (they probably also employed chemical acids). According to Bromehead, this impressive technology was initially expanded by the Roman conquerors; but eventually the Romans switched to using large masses of slaves (as described by Pliny), becuse they were not able to keep the mechanical drainage systems running.
I don’t necessarily agree with your depiction of the Romans as being “parasitic”. Just because they did not produce food, does not mean that they were not valued.
By “parasitic” I mean that Rome imported a lot and exported no products; but you are right in pointing out that the “military services” exported by Rome (and the common market) had probably a great economic value for the provinces. Still, do you agree that Rome was not self-sufficient?
The Romans were interested in math, its just that most of them weren’t located in Italia. Just look at the various mathematicians who lived in Alexandria, Athens, or Constantinople, and invented the fields of trigonometry (among others).
I challenge you to name one mathematical treatise, written between 100 BC and 500 AD, which is on the same tier as the work by Archimedes, Ipparchus or Apollonius (the difference in quality is so big that it is not subjective).
If you with “Roman” mean “anyone living in the Roman Empire” then yes, some Roman were interested in higher math. But the mathematics in the Imperial age was a shadow of what mathematics was before the Roman conquest. Trigonometry was first developed in Alexandria when Egypt was an independent Hellenistic kingdom; then in 146 BC the Romans installed a puppet king in Egypt, who proceeded to persecute the Greek èlites and to annihilate every intellectual opposition (he literally appointed a spearmen officer as the new director of the Library of Alexandria). To escape the persecution, many Greek intellectuals (including the mathematicians) escaped; some of them went to India, where they founded a school which continued to develop trigonometry (sine and cosine were first defined in India).
It is true that some (not so many) Romans learned greek maths even well into the V century (for example, emperor Procopius Anthemius studied under Proclus), but all the mathematics of the Imperial age consists of commentaries and collections of previous results. Sometimes they are brilliant commentaries, but still commentaries.
Also, the Romans heavily benefited the economy of the Greeks. An interconnected empire meant that Greek goods (such as amphorae, pottery, or other luxury items) could be traded anywhere in the empire, with only the nominal port taxes placed on it by the Empire.
I do not have much knowledge about the Imperial age, and maybe this was true in 100-200 AD, but it was definitely not true in the aftermath of the Roman conquest (see Rostovtzeff’s books).
Yes, the lead pollution was measured with arctic ice; this is the original paper. The authors belive that the peak in the eraly Imperial era was mainly caused by the Rio Tinto ore mines (so yes, it is pollution from all Europe, but mainly from Spain).
I agree with your main point that the first century BCE and the first century CE were a peak of economic developement of the ancient world (as shown by the graphs); I think that this is not in contradiction with what I am saying. In the first century BCE, many of the Roman provinces were of recent conquests, with much of their local institutions and know-how intact. Think of the Antikythera mechanism, which was built around the first century BCE.
In the III century, nobody could have built nothing even remotely similar to the Antikythera mechanism. If I understand correctly your overall thesis, this was because a shortage of fuel led to a simiplification of the society, so that the supply chain for building an Antikythera mechanism was not anymore feasible. But the main bottleneck in building an Antikythera mechanism is not the wood that you need to burn in making the cogs and the gears; the main bottleneck are the mathematical and mechanical knowledge necessary to design it, and the artigianal expertise needed to build its components. The Romans did not care about any of it. No respectable Roman learned mathematics: it was a suspiciously Greek, nerdy thing, unsuited to the practical Roman spirit. The first Latin translation of Euclid’s Elements was written in the Renaissance. I am sure that this played a significant role in the loss of mechanical technology after the first century (and, if you believe that mechanical technology was significant for the Hellenistic economy (a point about which scholars disagree), also played a role in the economic decline).
The vanishing of the economy was not, in my view, an unavoidable effect of resource depletion, but it was a consequence of the specific political and economical situation in the Imperial age. The Greek and Hellenistic states kept a complex and viable economy for much more centuries than “peak-Rome”, with much fewer resources to start with (a narrow bucket, in your metaphor). Byzantium/Costantinople/Istanbul was there before “peak-Rome”, and continued to be one of the main cities of the world long after Rome. How come Costantinople did not fill its bucket in 2000 years, while Rome (with access to a much wider bucket) did it in a few centuries? (maybe I am misrepresenting or excessively simplifying your view; I apologize if so)
Do you see a clear pattern in the sequence Rome → Costantinople → Baghdad → Cordoba → Costantinople → Cairo → Costantinople → London → New York? How does this succession fit in your model?
Thank you for the article! In my opinion, one of the main issues is that it does not seem to explain how the Eastern part of the Empire survived.
Rome was never economically self-sufficient. The city of Rome was a sink that absorbed food and products from the provinces, and produced nothing. The millions of inhabitants of Italy could survive only thanks to the subjugated provinces of the Empire.
Other areas of the Empire, notably Egypt and Gaul, were self-sufficient. In particular, Egypt was the main exporter of manufactured good (Roman travelers to Alexandria usually lamented the fact that the local inhabitant were greedy and always busy making money). In general, the Eastern part of the Empire was much richer than the West, was more urbanized, and had many more ancient and complex local administrative institutions.
When the Empire split between a Western and a Eastern half in the IV century, the Western part was in serious trouble. The only relevant food-exporting provinces left to the Western Empire was Africa. When Africa was lost, the Empire quickly fell. On the contrary, the fall of the Western Empire had no dramatic consequences on the Eastern Empire (ok, it was a big export market loss, which probably contributed a lot to the social tensions and the riots of the Justianan era; but a crisis due to a lack of an export market for your manufactured goods is way better than a crisis due to a lack of food to import).
As concerns your chart of civilizations moving in the north, in my opinion this is only the result of a bias: we learn in school about the civilizations more relevant to our history. I do not buy your thesis that the intensive agricolture drove the rise and fall of the civilizations:
Ptolemaic Egypt had an estimated population of about 8 millions of inhabitants, if I recall correctly. This is a great increase with respect to Ancient Egypt, and it was largely made possible by improvement in agricolture (not only plough, but irrigation and better agronomical techniques). This is after the “civilization hot spot” moved north of Egypt in your scheme—I am not sure if this count as a point for or against your model.
I have not the time now to look for estimations of the Roman population through history, but (if you trust my half-educated guess) I do not expect a demographic boom to have took place after the Roman conquest. The Roman Empire was forged by conquest, killings and enslavements. In The Economic and Social History of the Hellenistic World (a bit aged, but highly recommended!), Rostovtzeff speaks on the contrary of “race suicide” describing the demographic decline of Greece in the II and I century BCE. The parts of the Empire that were already civilized before the Roman conquest (namely Greece and the Near East), already had infrastructures and institututions before the Romans, which were ofted of superior quality (example: the celebrated Roman aqueducts worked by gravity, while e.g. the city of Pergamon in 180 BCE had watertight metal pipes which lifted water over a difference of altitude of >100 m. Also, the Roman aqueducts were designed by Greek slave engineers; the Romans never learned to project them on their own. Once the last educated Greek slaves dies, they could not buy anymore aqueducts. I hope that this specific example clarifies the general trend); and on top of this, after the Roman conquest, they also had to feed an economically parasite overlord. So I do not expect the population of the Eastern part of the empire to have substantially risen durin Roman rule (also Wikipedia says that it decreased, but I did not verify the sources). On the contrary, the population did probably rise (after the initial mass slaughters) in the formerly sparsely populated regions of Northern Western Europe; but these are also the provinces that in your chart became more relavant for civilization after the fall of Rome, so this does not seem to advance your theory.
There is no way in which Charlemagne’s empire was more relevant than the Umayyad Caliphate in 800 AD , in any reasonable “civilization” metric.
Southern Europe was economically more developed than northern europe until the XVI century, and while the causes that reversed this pattern are object of debate among scholars (I recommend this paper), I do not recall seeing soil depletion as a proposed cause (instead, the shift in global trade route and the centralized governments likely played a role).
This is anecdotal, but if you look at technological progress from 200BCE (the Punic Wars) and 200AD, you find that not much has happened, except the expansion of trade networks.
While this may be true, it overlooks the fact that many technologies that were developed in the precedent period (for example, the lighthouse, the cog and the gear wheel) were lost during the Roman age, not to be recovered until the Renaissance—or later.
Heron describes many artifacts that require tiny metal lives to be built, copying from previous Hellenistic sources, but at his age nobody knows anymore how to make tiny metal lives (he only describes a way to make big, wooden lives).
In the Imperial age the derivative was negative, but the technological and cultural level was obviously superior to the High Middle Ages. Between 500AD and 1000AD the urban society in Europe had become practically non-existent.
The fact that the Enterprise has survived for a long time may be due to the fact that captain Kirk overrules Spock in the areas where he is not competent (for example, when he estimates the probability of escaping from a black hole), while he is good enough in other aspects of his job.
The fact that Captain Kirk decides to ovverrule Spock’s 99,999999 % predictions is strong evidence that he does not trust them.
Yes, it is the relevant quantity in the limit of infinite number of uses of the channel. If you can use it just one time, it does not tell you much.
Actually the mutual information has some well-defined operational meaning. For example, the maximum rate at which we can transmit a signal through a noisy channel is given by the mutual information between the input and the output of the channel. So it depends on which task you are interested in.
Imagine a water wheel. The direction the river flows in controls the direction that the wheel turns. The amount of water in the wheel doesn’t change.
In this case you do not say “the wheel rotates in the direction of water increase”, but “the wheel rotates in the direction of water flow”.
I can see how you could argue that “the consciousness perceives past and future according to the direction of time in which it radiated heath”. But, if you mean that heath flow (or some other entropic-related phenomenon) is the explaination for our time perception (just like the water flow explains the wheel, or the DC tension explains the current in a circuit), this seems to me a bold and extraordinary claim, that would need a lot more evidence, both theoretical and experimental.
This is technically true of the universe as a whole. Suppose you take a quantum hard drive filled with 0′s, and fill it with bits in an equal superposition of 0 and 1 by applying a Hadamard gate. You can take those bits and apply the gate again to get the 0′s back. Entropy has not yet increased. Now print those bits. The universe branches into 2^bit count quantum branches. The entropy of the whole structure hasn’t increased, but the entropy of a typical individual branch is higher than that of the whole structure.
Yes, whenever you pinch a density matrix, its entropy increases. It depends on your philosophical stance on measurement and decoherence whether the superposition could be retrieved.
In general, I am more on the skeptical side about the links between abstract information and thermodynamics (see for instance https://arxiv.org/abs/1905.11057). It is my job, so I can not be entirely skeptic. But there is a lot of work to do before we can claim to have derived thermodynamics from quantum principles (at the state of the art, there is not even a consensus among the experts about what the appropriate definitions of work and heath should be for a quantum system).
Anyway, does the brain actually check whether it can uncompute something? How is this related with the direction in which we perceive the past? The future can (in principle) be computed, and the past can not be uncomputed; yet we know about the past and not about the future: is this that obvious?
[...] The universe as a whole behaves kind of like a reversible circuit.
This is another strong statement. Maybe in the XVIII century you would have said that the universe is a giant clock (mechanical philosophy), and in the XIX century you would have said that the brain is basically a big telephone switchboard.
I am not saying that it is wrong. Every new technology can provide useful insights about nature. But I think we should beware not to take these analogies too far.