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Post by raybar on Dec 8, 2013 11:42:43 GMT -5
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mike
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Post by mike on Dec 9, 2013 23:44:52 GMT -5
Absolutely fascinating. The conclusion that cooking our food is responsible for humans having the most neurons is unexpected, at least by me. How soon after the discovery of fire was cooking discovered? Probably very soon, when the first piece of meat accidentally fell in the fire.
I liked the logical step by step way she laid out her theory.
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Post by Blarney Rubble on Dec 10, 2013 3:50:28 GMT -5
Nice presentation, but her theory is almost certainly wrong. Human control of fire (and therefore the ability to cook food) was not widespread until about 100,000 years ago, according to paleontological and archaeolgical evidence. The human brain had already long surpassed that of other primates. The records show that homo habilis was using complex tools two million years ago. Homo erectus also used tools and were intelligent enough to build rafts to travel between islands 1.8 million years ago - long before cooking was invented. If the paleontological records are correct, the the presumed accelerated development of the human brain cannot possibly be attributable to advent of cooking.
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Post by raybar on Dec 10, 2013 11:42:39 GMT -5
"...almost certainly wrong..." Well, maybe she's dead wrong, or maybe she's dead on, or maybe cooking was a contributing factor. I would like to hear from other professionals in the field before making any judgment at all.
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Post by Blarney Rubble on Dec 10, 2013 17:17:37 GMT -5
Well, it's easy to check the acts I posted above. And if humans were using complex tools a couple of million years before cooking was invented/discovered, then simple deduction should tell you that it wasn't cooking that made them extra smart. In fact humans would have to be smarter than other primates to invent cooking in the first place, wouldn't they? Two million years of evolution later you still don't see great apes roasting nuts, do you?
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mike
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Post by mike on Dec 10, 2013 19:17:48 GMT -5
The correlation she is reporting is between brain capacity measured as number of neurons versus the presence or absence of cooking and the graph at about 11.50 minutes shows a steady but gradual brain size increase up to about 1.8 MY ago followed by a much steeper rise after 1.8 MY ago. I question whether homo habilis was using "complex" tools - maybe just very basic tools - but have not tried to verify this so feel free to correct. While simple tool making may have developed in parallel with the gradual increase in brain capacity, I think the presenter was proposing that further advances in cognition beyond simple toolmaking were enabled by cooking.
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Post by Blarney Rubble on Dec 11, 2013 4:41:23 GMT -5
"Tools Sites for Homo habilis revealed at least 11 different kinds of tools, which range in size from a tennis-ball to a walnut and are known collectively as the ‘Olduvan industry.’ These tools were used for hunting, self-defense, and food preparation. They include certain types of choppers, notched tools, flakes, chisels, scrapers, and gouging and engraving tools. In addition, these tools were adequate for activities such as skinning animals, such as antelope. " tolweb.org/treehouses/?treehouse_id=3710But apart from that, I can't see how such a radical change in the architecture of the brain (ie, an incresse in neuron density) could take place in such a short space of time (thousands rather than millions of years) after the advent of cooking. And again, humans would have to be more intelligent than other primates in order to have invented cooking (which requires knowledge of creating and controlling fire). Ergo the advent of cooking couldn't have caused them to be more intelligent than other primates. |
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mike
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Post by mike on Dec 11, 2013 12:24:50 GMT -5
It's not neuron density that changes it's brain size. As the video showed, primates all have roughly the same neuron density, but humans have bigger brains than, say, gorillas, therefore more neurons. Elephants have much bigger brains than humans but a lower neuron density. Gorillas have smaller brains than humans at the same neuron density. Humans are smarter than elephants and gorillas because we have more neurons.
The video claims that there is a correlation between number of neurons and the use of cooking. Your statement "I can't see how such a radical change in the architecture of the brain (ie, an incresse in neuron density) could take place in such a short space of time" is missing the point. Whether you can see it or not, it did happen, unless you want to dispute the existence of this correlation. The correlation seems to be a fact.
Correlation does not necessarily mean causality and the controversial part of the video should be her theory that there is a causal relationship, not the existence of the correlation.
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Post by Blarney Rubble on Dec 11, 2013 12:53:24 GMT -5
Yes, I meant quantity, not density. The video claims that there is a correlation between the number of neurons and cooking, but I don't see it. You say correlation does not necessarily mean causality, but a correlation without a causal relationship wouldn't be a correlation, would it? It would just be a coincidence. A correlation always implies a causal relationship between two events.
Apart from that, I would be very dubious about any claim of a correlation between two events that can't be accurately dated to within less than 100,000 years. Nobody knows for sure when cooking was "invented", or when human brain power accelerated/increased. How can anyone claim a correlation - or even a coincidence - between two events that might have occurred hundreds of thousands of years apart? And again, it seems self-evident to me that humans would have to have already been more intelligent that other primates in order to have invented cooking. And if humans were smarter than other primates before they invented cooking, then it couldn't have been cooking that made them smart.
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mike
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Post by mike on Dec 11, 2013 14:48:36 GMT -5
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Post by Blarney Rubble on Dec 11, 2013 15:18:14 GMT -5
Wiki is edited by idiots. It's not a reliable source of information on any subject. And I don't think that's even Wiki. In any event the definition of correlation given in that article is the secondary meaning, which applies to statistics. But even here a causal connection is almost always implied. My Oxford English Dictionary, which is a reliable source - indeed, the definitive source - defines correlation as: "Correlation: 1. A causal relationship or connection between two or more things." cor·re·la·tion (kôr-lshn, kr-) 1. A causal, complementary, parallel, or reciprocal relationship, especially a structural, functional, or qualitative correspondence between two comparable entities: www.thefreedictionary.com/correlationThe clue is in the "related" part of the word. Correlated events are *related* to each other. Which is to say there is a causal connection - albeit one whose nature is not always understood - between them. |
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mike
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Post by mike on Dec 11, 2013 15:48:28 GMT -5
Ignore wiki and choose your own source reference. Any scientist, engineer or statistician knows that a correlation does not necessarily mean a causal relation. The OED may be simply bowing to a widespread improper usage, as it sometimes does.
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Post by Blarney Rubble on Dec 11, 2013 17:02:38 GMT -5
The OED borrows improper word usage? Haha! You should write to them and tell them. I'm sure they'd love to hear from you : )
A correlation IS a causal relationship. If any scientist, engineer or statistician "knows" otherwise they're wrong.
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mike
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Post by mike on Dec 11, 2013 23:28:53 GMT -5
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Post by Blarney Rubble on Dec 12, 2013 1:52:45 GMT -5
Of course there's a correlation - ie, a causal link - between chocolate consumption and Nobel prizewinners. People who use a lot of brain power tend to eat a lot of chocolate.
I know I do!
: D
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Post by Blarney Rubble on Dec 12, 2013 5:57:53 GMT -5
Incidentally, correlations - or what appear to be correlations - are often used to support bogus claims. One of the most widely-publicized fraudulent correlations in recent years was that presented by Al Gore in his (riddled-with-factual-errors) movie, "An Inconvenient Truth", where he showed a double graph showing CO2 levels alongside global temperature fluctuations. The two graphs corresponded closely. This, he said, was proof of a causal link between CO2 levels and warming of the planet. What he failed to mention - either deliberately or because he didn't actually know - was that the CO2 graph was actually tracking the temperature graph, and that CO2 levels were rising and falling as a result of higher and lower temperatures. In other words, CO2 levels increase when the temperature went up, and not vice-versa. So the causal relationship was real (as was the correlation), but it was the other way round, and refuted rather than supported his theory. When this basic error was pointed out to Gore, he refused to discuss it.
Another correlation that has been deliberately misinterpreted is the one which appears to show a reduction in fatalities from an infectious disease and mass vaccination. This correlation fails to take account of the fact that infectious diseases have a natural life span, and they become less virulent and less deadly over time. Instead, the stats assume that the progress of the disease is static, and would continue in a "straight line" in the absence of medical intervention. Most vaccination programs are introduced when the disease in question is already losing its potency. The reason for the correlation is not that the vaccine is effective, but that vaccines are invariably introduced after the epidemic has peaked.
Similarly, the correlation between recovery from illness and medical treatment is highly misleading, and gives medicine far more credit than it deserves. The "trick" here is that most illnesses (98%) go away of their own accord. But people usually only go to see a doctor, or present at hospitals, when the symptoms of their illness have become acute. They receive medical treatment (usually pills), and within a few days they are feeling better. They attribute their recovery to the medical treatment they received, but in most cases they would have recovered anyway, because recovery always follows an illness's acute phase (where it doesn't, the outcome is death). Countless millions of people have been fooled by this "trick".
So while correlations can be genuine (a non-causal "correlation" is called a coincidence), the causal connection - ie, the reason for the correlation - is not always known or fully understood.
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Post by Blarney Rubble on Dec 15, 2013 0:57:53 GMT -5
This whole "fallacy alert" is itself fallacious.
"During the past two months, every time the cheerleaders have worn blue ribbons, the basketball team has won. So if we want to keep winning, they had better continue to wear the blue ribbons..."
"Every time Jerome Bettis carries more than 30 times, the Steelers win."
There is no correlation here. These are examples of coincidence, not correlation. In order for two events to be a correlation, there would have to be a relationship (that's the root meaning of the word), and the two events would have to occur with a level of frequency and consistency that coincidence could be ruled out as statistically implausible. The fact that two events coincide a few times does not make them correlated.
All the definitions I linked to do, in fact, imply a causal connection.
You've highlighted "or reciprocal relationship". A reciprocal relationship is always causal.
Statistcs. Yes, I specifically exempted statistical correlation in an earlier post. The term correlation is used in statistics, and other branches of mathematics, to describe periodic repetition of numbers, "clustering" etc. But statistical correlations are theoretical, not real.
"An act of correlating or the condition of being correlated."
You're saying this doesn't imply a causal relationship? Really? It does, of course.
You've also highlighted "a mutual or reciprocal relationship between two or more things".
A reciprocal relationship is by definition causal!
There is nothing in the rest of the text you posted to support the claim that correlations can have a non-causal basis.
"Since most of the definitions you posted don't even mention causality, why are you so insistent on including it?"
Every dictionary and encyclopedia definition (including the one I posted. Look again) begins with the words "A causal..."
As to why I am so insistent on including it, I am refuting the claim made by Mike in another thread, which he continued in a new thread (can't imagine why), regarding a claim made in a TED video that the superiority of human intelligence (over primate intelligence) can be attributed to the advent of cooking. I made the argument (among others) that humans would have to have been more intelligent than other primates in the first place to have invented cooking (since this also implies knowledge of controlling fire etc.) "Ergo the advent of cooking couldn't have caused them to be more intelligent than other primates."
Mike replied that I was missing the point: "Whether you can see it or not, it did happen, unless you want to dispute the existence of this correlation. The correlation seems to be a fact. Correlation does not necessarily mean causality..."
I then pointed out that, not only was there no correlation (since it is not known for sure when cooking was "invented", or when human brain power accelerated/increased. How can there be a correlation between two events that may have occurred 100,000 years or more apart?), but that even if the two things did happen at about the same time, this would not mean that they were correlated. Again, a correlation is not merely a coincidence. In order for two events to be correlated, there has to be a meaningful connection or relationship between them.
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