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Post by betahat on Oct 22, 2009 18:02:08 GMT -5
I think the answer is that the correlation with brain size is very rough. As Alisa points out, Neanderthals had larger brains than humans (never mind all the animals with larger brains than us). Measuring skull sizes seems to be only in the domain of the study of human ancestors, comparing different links on the transition from apes.
I think physical brains obviously are related to intelligence in many ways but that the actual relationship is more subtle. Wikipedia tells me:
Several neurophysiological factors have been correlated with intelligence in humans, including the ratio of brain weight to body weight [1] and the size, shape and activity level of different parts of the brain.[2] Specific features that may affect Intelligence Quotient (IQ) include the size and shape of the frontal lobes, the amount of blood and chemical activity in the frontal lobes, the total amount of gray matter in the brain, the overall thickness of the cortex and the glucose metabolic rate.
Now none of these things are strongly linked to the kind of crap you see from Rushton (not the Bell Curve author - that's Murray and Hernstein) or the other racist sites you see when you google "cranial capacity" (just look - I get several hits for David Duke, Stormfront, etc.). If Rushton were to go out and study the thickness of the cerebral cortex or the shape of the frontal lobe, maybe I would be more willing to buy it. But skull size and shape are only indirect indicators of brain physiology and the functioning of different parts of the brain, and it must surely be these things that affect performance on IQ tests.
As far as I can tell, the evidence for genetically related group differences in intelligence being important is not that strong. Important evidence against it includes (a)apparently decreasing black-white IQ gaps in the last 30 years by about 30% (which obviously cannot have any genetic explanation) (Nesbitt 2005) (b)the apparent increase in IQ scores everywhere at a rate of about 3 points per decade, called the Flynn effect.
While it is interesting to note that average IQs of blacks and whites in America have increase over the last few centuries (to the point where the average black today has a higher IQ than the average white 100 years ago) the gap has persisted. I take this as evidence against mainly genetic factors, but others have interpreted it the other way. Studies of European Jews and Southern Italian immigrants showed remarkable increase among these immigrant groups over the last century (the Southern Italian - white Anglo American gap was apparently bigger than the current black-white gap of about 17 points).
Probably the two most important questions though are (a)is IQ (or g, or any other one dimensional measure) the right way to measure intelligence? and (b)is race and skin color a biologically and scientifically valid concept or a social construct?
I think we have made some progress on (a), as people study different types of intelligence tests. We're still waiting on the human genome project to shed some light on (b) - if we are going to talk about genes and genetic factors, we had better get beyond skin color and "race" as we understand it and identify particular genetic markers and sequences, because that's the only way to accurately quantitatively assess the contribution of genetics to whatever measure of intelligence we choose to use. So far there hasn't been much progress on that.
Anyway, I'm certainly not an expert on this stuff but I don't think "cranial capacity" is an active topic of scientific research (except among anthropologists studying human ancestors), and that's not because of political correctness - it's because it's a very crude measure.
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Post by palaver on Oct 22, 2009 19:55:59 GMT -5
Probably the two most important questions though are (a)is IQ (or g, or any other one dimensional measure) the right way to measure intelligence? and (b)is race and skin color a biologically and scientifically valid concept or a social construct? I've been floating Gardner's theory of multiple intelligences in my sig for a while. IQ seems to only measure logical, spatial, and linguistic intelligence. The rapid population gains in IQ (the described Flynn Effect) seem to stem from our visually stimulating media culture. This gain in IQ was probably offset by a decline in other areas of intelligence, such as naturalistic, linguistic, intrapersonal and bodily-kinesthetic intelligence. What we're also seeing is the catch-up effect in less developed countries which have made improvements in their education system and have also imported new modern visual medias. And also nutrition! Well fed brains are active brains. All this fits with my idea of heredity being the greatest limiting factor for the upper classes with environment being the limiting factor for the lower classes. It's hard to described IQ in racial or genetic terms since many people are not operating at their potential. However, it is attractive to correlate the two because controversy is a kind of fame to those who are dishonest enough to plead the case. One thing I've found most incredulous is the claim that we and our children are on average smarter than America's founding fathers. But when you read the their letters and essays, you would only hope that Americans were as intelligent. Maybe those great men possessed only a linguistic intelligence, but even so, does it compare to what we have gained in its place. And were they alive today, I would not classify them as morons. IQ's hard measurements so seem to contradict what we intuitively perceive as intelligence.
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Post by milkman's baby on Oct 22, 2009 20:12:24 GMT -5
I think the answer is that the correlation with brain size is very rough. As Alisa points out, Neanderthals had larger brains than humans (never mind all the animals with larger brains than us). Measuring skull sizes seems to be only in the domain of the study of human ancestors, comparing different links on the transition from apes. I think physical brains obviously are related to intelligence in many ways but that the actual relationship is more subtle. Wikipedia tells me: Several neurophysiological factors have been correlated with intelligence in humans, including the ratio of brain weight to body weight [1] and the size, shape and activity level of different parts of the brain.[2] Specific features that may affect Intelligence Quotient (IQ) include the size and shape of the frontal lobes, the amount of blood and chemical activity in the frontal lobes, the total amount of gray matter in the brain, the overall thickness of the cortex and the glucose metabolic rate. Now none of these things are strongly linked to the kind of crap you see from Rushton (not the Bell Curve author - that's Murray and Hernstein) or the other racist sites you see when you google "cranial capacity" (just look - I get several hits for David Duke, Stormfront, etc.). If Rushton were to go out and study the thickness of the cerebral cortex or the shape of the frontal lobe, maybe I would be more willing to buy it. But skull size and shape are only indirect indicators of brain physiology and the functioning of different parts of the brain, and it must surely be these things that affect performance on IQ tests. As far as I can tell, the evidence for genetically related group differences in intelligence being important is not that strong. Important evidence against it includes (a)apparently decreasing black-white IQ gaps in the last 30 years by about 30% (which obviously cannot have any genetic explanation) (Nesbitt 2005) (b)the apparent increase in IQ scores everywhere at a rate of about 3 points per decade, called the Flynn effect. While it is interesting to note that average IQs of blacks and whites in America have increase over the last few centuries (to the point where the average black today has a higher IQ than the average white 100 years ago) the gap has persisted. I take this as evidence against mainly genetic factors, but others have interpreted it the other way. Studies of European Jews and Southern Italian immigrants showed remarkable increase among these immigrant groups over the last century (the Southern Italian - white Anglo American gap was apparently bigger than the current black-white gap of about 17 points). Probably the two most important questions though are (a)is IQ (or g, or any other one dimensional measure) the right way to measure intelligence? and (b)is race and skin color a biologically and scientifically valid concept or a social construct? I think we have made some progress on (a), as people study different types of intelligence tests. We're still waiting on the human genome project to shed some light on (b) - if we are going to talk about genes and genetic factors, we had better get beyond skin color and "race" as we understand it and identify particular genetic markers and sequences, because that's the only way to accurately quantitatively assess the contribution of genetics to whatever measure of intelligence we choose to use. So far there hasn't been much progress on that. Anyway, I'm certainly not an expert on this stuff but I don't think "cranial capacity" is an active topic of scientific research (except among anthropologists studying human ancestors), and that's not because of political correctness - it's because it's a very crude measure. Interesting. I do indeed believe that we place too much value on IQ tests, though they are an acceptable form of generalizing an individuals capabilities. As for question b), it's rather complex to answer this. In the context of this discussion, one may make a point that intelligence is a genetic factor passed down from the ancestors (I'm aware there is a thread on EAN about this). But that would indirectly tie in race, since race was originally intended to define a group of people who look similar because they're ancestors hailed from the same region. Then comes the question of whether geography plays a role in the "evolution of intelligence," or at least evolution in whatever parts of the brain control the appropriate areas of intelligence. Recall, betahat, our short discussion in the Silly Correlations thread about how northern, colder civilizations on earth were forced to advance technologically than those able to live naked and simplistically in warmer, tropical climates. I'm too lazy to dig through endless sources of anthropological studies to confirm, but I wonder if perhaps there is any evidence (or not) as to whether the human brain evolved in such environments appropriately as well.
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s
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Post by s on Oct 22, 2009 21:38:26 GMT -5
Either way, I think it's more of an environmental factor. If you look at the way most asians are brought up to study hard and are a lot more disciplined in the academic areas, it makes sense that they end up making better use with what they have. I agree completely that being intelligent is far more complex than having a large brain. Like they say, it's not the size that matters, it's how you use it! How would you even measure intelligence between those who have exercised their brain to a higher potential than those who haven't? The homo neanderthalis people (neanderthals) had larger brains than the homo sapiens (us), but were still wiped out by the latter - though then again, that probably has more to do with population size than anything! OR perhaps with smaller brains comes higher levels of aggressiveness? I don't know enough about it to make a judgement, but it's a fact I've always found interesting! I actually think neanderthals were more intelligent than modern humans. We know they made tools, fire, musical instruments (flutes), had religion, etc. They also had the same exact adaptations in their vocal chords for complex speech as humans do. The reason they died out was because a neanderthal body required twice the amount of calories (food) of a homo sapien. In addition, their biology limited them to jabbing spears rather than throwing them. That's why we actually always find jabbing spears at neanderthal camp grounds. As the ice age ended, game became more free roaming and thus jabbing spears were ineffective compared to throwing spears. So, they required twice the amount of food and were probably, due to their biology, only able to collect something like half the amount of food as a homo sapien. That they managed to survive as long as they did considering their relative physical inferiority for the ending of the ice age environment is amazing. I credit that to their intelligence.
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s
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Post by s on Oct 22, 2009 21:42:37 GMT -5
Either way, I think it's more of an environmental factor. If you look at the way most asians are brought up to study hard and are a lot more disciplined in the academic areas, it makes sense that they end up making better use with what they have. I agree completely that being intelligent is far more complex than having a large brain. Like they say, it's not the size that matters, it's how you use it! How would you even measure intelligence between those who have exercised their brain to a higher potential than those who haven't? The homo neanderthalis people (neanderthals) had larger brains than the homo sapiens (us), but were still wiped out by the latter - though then again, that probably has more to do with population size than anything! OR perhaps with smaller brains comes higher levels of aggressiveness? I don't know enough about it to make a judgement, but it's a fact I've always found interesting! Cranial capacity does have something like a 50% correlation with IQ. Whether the intelligence differences are due to environment or genetics doesn't really matter; the intelligence differences are still there. However, there is strong evidence that the differences are due to genetics. Off the top of my head, I can remember a blogger that analyzed a gene mapping database looking for the presence of genes known to effect IQ in different races. For nearly every gene he looked at, the genes known to increase IQ were present in more Asians than whites and more whites than blacks. The opposite held true for genes known to hurt IQ. As for the height differences, I think that's pretty clearly genetic. Even 2nd-3rd generation Asians in the US are shorter. Plus, I don't know how you're going to explain away really tall people like the dutch (average height = 6'2, ~6'4 in the northern part of the country) as cultural.
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s
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Post by s on Oct 22, 2009 21:46:55 GMT -5
I think the answer is that the correlation with brain size is very rough. As Alisa points out, Neanderthals had larger brains than humans (never mind all the animals with larger brains than us). Measuring skull sizes seems to be only in the domain of the study of human ancestors, comparing different links on the transition from apes. I think physical brains obviously are related to intelligence in many ways but that the actual relationship is more subtle. Wikipedia tells me: Several neurophysiological factors have been correlated with intelligence in humans, including the ratio of brain weight to body weight [1] and the size, shape and activity level of different parts of the brain.[2] Specific features that may affect Intelligence Quotient (IQ) include the size and shape of the frontal lobes, the amount of blood and chemical activity in the frontal lobes, the total amount of gray matter in the brain, the overall thickness of the cortex and the glucose metabolic rate. Now none of these things are strongly linked to the kind of crap you see from Rushton (not the Bell Curve author - that's Murray and Hernstein) or the other racist sites you see when you google "cranial capacity" (just look - I get several hits for David Duke, Stormfront, etc.). If Rushton were to go out and study the thickness of the cerebral cortex or the shape of the frontal lobe, maybe I would be more willing to buy it. But skull size and shape are only indirect indicators of brain physiology and the functioning of different parts of the brain, and it must surely be these things that affect performance on IQ tests. As far as I can tell, the evidence for genetically related group differences in intelligence being important is not that strong. Important evidence against it includes (a)apparently decreasing black-white IQ gaps in the last 30 years by about 30% (which obviously cannot have any genetic explanation) (Nesbitt 2005) (b)the apparent increase in IQ scores everywhere at a rate of about 3 points per decade, called the Flynn effect. While it is interesting to note that average IQs of blacks and whites in America have increase over the last few centuries (to the point where the average black today has a higher IQ than the average white 100 years ago) the gap has persisted. I take this as evidence against mainly genetic factors, but others have interpreted it the other way. Studies of European Jews and Southern Italian immigrants showed remarkable increase among these immigrant groups over the last century (the Southern Italian - white Anglo American gap was apparently bigger than the current black-white gap of about 17 points). Probably the two most important questions though are (a)is IQ (or g, or any other one dimensional measure) the right way to measure intelligence? and (b)is race and skin color a biologically and scientifically valid concept or a social construct? I think we have made some progress on (a), as people study different types of intelligence tests. We're still waiting on the human genome project to shed some light on (b) - if we are going to talk about genes and genetic factors, we had better get beyond skin color and "race" as we understand it and identify particular genetic markers and sequences, because that's the only way to accurately quantitatively assess the contribution of genetics to whatever measure of intelligence we choose to use. So far there hasn't been much progress on that. Anyway, I'm certainly not an expert on this stuff but I don't think "cranial capacity" is an active topic of scientific research (except among anthropologists studying human ancestors), and that's not because of political correctness - it's because it's a very crude measure. Interesting. I do indeed believe that we place too much value on IQ tests, though they are an acceptable form of generalizing an individuals capabilities. As for question b), it's rather complex to answer this. In the context of this discussion, one may make a point that intelligence is a genetic factor passed down from the ancestors (I'm aware there is a thread on EAN about this). But that would indirectly tie in race, since race was originally intended to define a group of people who look similar because they're ancestors hailed from the same region. Then comes the question of whether geography plays a role in the "evolution of intelligence," or at least evolution in whatever parts of the brain control the appropriate areas of intelligence. Recall, betahat, our short discussion in the Silly Correlations thread about how northern, colder civilizations on earth were forced to advance technologically than those able to live naked and simplistically in warmer, tropical climates. I'm too lazy to dig through endless sources of anthropological studies to confirm, but I wonder if perhaps there is any evidence (or not) as to whether the human brain evolved in such environments appropriately as well. To think that the races aren't different in intelligence due to environmental adaptations over evolution is pretty retarded IMO. There's obviously tons of physical differences: height, weight, bone structure, skin color, muscle fiber differences, hair color differences, skin texture differences, hair texture differences, facial differences, tooth differences, eye differences, food digestion differences (Eg milk), allergen differences, etc. For something that the environment would barely have an effect on relative to survival like hair texture to still have a huge effect on it, it would be pretty stupid to think that a trait incredibly important to survival like intelligence would remain unchanged. At the end of the day, there are 2 view points: 1) Some races are superior to others in intelligence. There is a huge body of evidence to support this. It also makes logical sense. 2) All the races are equal in intelligence. There is literally no evidence at all to support this. It also makes no logical sense. View point 1 is clearly 120348120481204812048x more reasonable than view point 2. People just want to believe in number 2 because it makes them feel good I guess.
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s
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Post by s on Oct 22, 2009 21:52:43 GMT -5
It's hard to described IQ in racial or genetic terms since many people are not operating at their potential. Everyone operates at their full potential. If someone could operate more efficiently by working harder but they're not working harder then they're not capable of working harder in that moment. That's like saying that a computer isn't operating at its full speed because you can add more transistors to it. Output is effected by limiting factors; for some it's intelligence and for others' its effort. Either way, the output is limited.
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Post by palaver on Oct 22, 2009 21:58:51 GMT -5
^ I take it, you don't believe in education and that you never went to school because you were born at "full potential". It also sounds as if you don't agree with the idea of potential. I actually think neanderthals were more intelligent than modern humans. Ahaha. Then you won't mind me calling your theories neanderthal--intelligent enough to invent, but not enough to survive. I kid. I kid.
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Post by betahat on Oct 22, 2009 23:49:46 GMT -5
I guess the correlation of height and intelligence doesn't really help your case, since at 0.2 (http://en.wikipedia.org/wiki/Height_and_intelligence) it appears to be about the same size as the correlation with cranial measurement. My understanding is that cranial measurement (cranial capacity? - perhaps you could clarify where your .5 figure comes from and whether it refers to external or skull measurements, i.e. cranium, or brain volume measured via MRI) is not that strongly related to IQ (about .2), but this study pubpages.unh.edu/~jel/brainIQ.htmltells me that brain size measured by MRIs has a correlation as high as .43. So brain size matters, but skull size is only loosely related to brain size. Perhaps you could cite what study you used to get .5, which seems awful high, especially for "cranial capacity?" I don't know if there is a neanderthal brain somewhere that people analyzed with an MRI - my guess is that we haven't done that, so a lot of what is said about Neanderthal vs. our intelligence is highly speculative. I would be curious to see your sources for the claim that they have found a genetic marker correlated with IQ. Perhaps you should read this article: www.nytimes.com/2007/11/11/us/11dna.html?_r=1I believe that is your source. Needless to say it does not seem very convincing. Not that I deny the possibility of genetically based "racial" differences in IQ. As the Times article makes clear, there may come a day when we can assert that such and such a combination genes that are more prevalent among such and such a population causes higher IQ controlling for all other factors. But that day has yet to come. I just think you're really overstating your case with this: "1) Some races are superior to others in intelligence. There is a huge body of evidence to support this. It also makes logical sense. 2) All the races are equal in intelligence. There is literally no evidence at all to support this. It also makes no logical sense. View point 1 is clearly 120348120481204812048x more reasonable than view point 2. People just want to believe in number 2 because it makes them feel good I guess. " The existence of intelligence differences and their correlation with skin pigmentation is undeniable, but their cause is still in question. We all know correlation does not imply causation, yada yada yada. The mere existence of racial differences provides absolutely no evidence about the existence or magnitude of genetic differences in intelligence or their correlation with "race." Any before we debate this further you should check out Malcolm Gladwell's excellent piece here: www.gladwell.com/2007/2007_12_17_c_iq.htmlAmong other tidbits is that we Asians maybe aren't so smart. We're just harder working...
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Post by alisa on Oct 23, 2009 3:26:45 GMT -5
Lots of interesting theories and insights here! s - that's really interesting re: neanderthals. I think I'm actually going to try and find out more about them. I agree with betahat who says that the correlation between skull size and brain size is not an exact science either, so it would be almost impossible to tell through studies of skull size whether or not another race were more intelligent. As far as asians scientifically proven to be more intelligent, if this is the case (I haven't yet gotten around to reading any of the studies), wouldn't it be a question of natural selection? I realise this doesn't affect the final results which would indicate that asians are smarter, but what I was writing earlier regarding the stereotypical asian attitude to hard work would have contributed to this over time as the more successful ones who have maximised their intellectual capabilities have grown dominant within the asian races over time. Saying that everyone already operates at their full potential is misleading as it doesn't take into account the environmental factors of their upbringing to date. It would then require us to be able to measure 'potential' to make that judgement, of which we wouldn't be able to limit to just intelligence, since potential can refer to physical accomplishments as well (by that I'm defining a line between the physical nature of intelligence and physical strength/dexterity/etc). From a personal perspective, I KNOW I have unused intellectual potential which would become apparent under the right circumstances, or would have become apparent under different circumstances which have led me to where I am now.
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Post by palaver on Oct 23, 2009 5:59:26 GMT -5
^ Have you heard that parenthood lowers your IQ by a good amount? And to think that it actually requires less intelligence than advertised! (Weird, I just felt a strong sense of deja vu.) Since we're already prostrate before the alter of IQ, what does the smartest person from the smartest race have to say on the nature of his (or her) intelligence? Maybe there's an ice man waiting to be defrosted who can help us these questions. Who else is more entitled to this judgment? I'll pull one out of the hat: Marilyn vos Savant, reported as having the highest ever recorded IQ (a silly title given the variations in testing) I think intelligence is like this. So many factors are involved that attempts to measure it are useless. Not that IQ tests are useless. Far from it. Good tests work: They measure a variety of mental abilities, and the best tests do it well. But they don’t measure intelligence itself.
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Post by alisa on Oct 23, 2009 8:31:59 GMT -5
^ I hope that was a generalised comment! But i definitely belive it. I had to read what I posted a billion times and I'm still not sure it made sense. My memory has gone to the dogs as well and I attempted a sudoku tonight and couldn't finish it! Perhaps it's because mum's are supposed to be able to multi task at higher levels than the regular person and with divided attention comes the inability to concentrate fully on one thought pattern? haha - who cares. Parenthood is worth going a bit dumb for.
Whenever I think of IQ measurement scales I can't help but remember one of those reality tv shows with these little child geniuses. They were giving one little boy an IQ test and his response to his score or whatever, (and I'm paraphrasing here!) was 'how can you measure IQ against an imperfect scale?' (Okay, the little guy put it a lot more eloquently than that, but I thought, what a good point. Someone - presumably less than perfect - created the IQ test and scale, so how can we possibly measure intelligence based on that?! Binet pretty much said something similar). On another note, out of curiosity, are there any Mensa members in EAN?
I fear we've somewhat deviated from the original topic! I reckon we should start a new thread because there's still lots more interesting stuff to discuss regarding intelligence etc. I'm facinated by all the different theories!
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Post by alisa on Oct 23, 2009 8:41:12 GMT -5
^ Have you heard that parenthood lowers your IQ by a good amount? And to think that it actually requires less intelligence than advertised! (Weird, I just felt a strong sense of deja vu.) Since we're already prostrate before the alter of IQ, what does the smartest person from the smartest race have to say on the nature of his (or her) intelligence? Maybe there's an ice man waiting to be defrosted who can help us these questions. Who else is more entitled to this judgment? By the way, as far as the initial comment you made, personally I feel it doesn't, in fact, take much intelligence at all to raise a child. We're dealing with human instinct at its most basic! Society and science (and other so called 'experts') just play on parents' insecurities and make us feel like we need an IQ of a savant to raise a kid, which isn't that case at all! Look at I Am Sam! hahaha! All you need is love (and shelter and food and clothing). Also, speaking of my brain going dumb, I read the first sentence of the second paragraph you wrote about 50 times thinking, 'wtf'? But I take it you mean 'altar'? And you're right - we'll never really know or be able to measure the nature of intelligence faultlessly - there can only ever be a 'guide' to make generalised assumptions - as intelligence is not linear in the slightest.
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Post by admin on Oct 23, 2009 9:25:13 GMT -5
^ Have you heard that parenthood lowers your IQ by a good amount? [/blockquote][/i][/quote] I would hazard a guess that the measurement is due to the results of the reduced sleep that accompanies the role, not that the person somehow loses intelligence.
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Post by palaver on Oct 24, 2009 21:13:52 GMT -5
^A measure of tiredness? I think they might control for that. By the way, as far as the initial comment you made, personally I feel it doesn't, in fact, take much intelligence at all to raise a child. We're dealing with human instinct at its most basic! Fine, it takes quite a bit of intelligence to raise functioning and successful offspring. To do that requires control--otherwise there's junk food and the television. I can't think of anything more mentally exhausting than trying to get one of those terrible creatures to do something you want without ever having to lay a hand on them! This is where they say coercion comes natural to human beings. If you bought any of those Baby Einstein videos, you can get refund. They don't improve the IQ of the child because visual over stimulation impairs their language development, producing ineloquent motion addicted ADD children--a painfully evident handicap of modern generations.
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