One of the special things about the WAIS-IV IQ test is it provides norms even for people in the 85 – 90.9 age range. It’s not that hard to get a high IQ when you’re this old. If an 85-year-old scores as high as the average 25-year-old on all the core subtests of the WAIS-IV, they get a verbal reasoning IQ of 105, a perceptual reasoning IQ of 140, a processing speed IQ of 147, a working memory IQ of 119, and a full-scale IQ of 134.
However even these scores might be a massive underestimate. IQ is supposed to measure how smart you are compared to others your age. So if a 10-year-old is as smart as the average (white) American 10-year-old, his IQ is 100. By definition. If he’s smarter than 90% of American 10-year-olds, his IQ is 120. By definition.
So even though people get smarter with age, up until their 20s, and then get dumber with age, their IQs remain relatively constant, because IQ reflects your rank order among others your age.
The problem is, the WAIS-IV standardization sample excludes anyone who suffers from dementia or other illnesses that affect test performance. At first this sounds reasonable because you may want test norms to reflect the “normal” non-pathological population. But nearly half of all Americans over the age of 85 suffer from dementia!
So let’s say you are someone who has had average cognitive ability for his age for your entire life, from age 10 to 85. At age 10 your IQ will be 100, but at age 85, your IQ could drop to perhaps well below 90. Why the decline if you remain average for your age at both ages? Because at age 10, you’re compared to virtually all American 10-year-olds, while at age 85, you’re compared to the relatively brighter (on average) subset who have escaped dementia or even death.
One could argue that the elderly deserve bonus points on IQ tests to negate the fact that they are being compared to an increasingly elite reference group.
If we want the IQ to have the same meaning at age 10 that it has at age 85, then perhaps people with dementia should be included in the standardization sample, and for that matter, so should dead people. I’m not suggesting psychologists should dig up graves and administer the WAIS-IV to skeletons, but I am suggesting that they should statistically estimate how those dead people would have performed at age 85 had they not died, and include said scores in the standardization sample.
Pumpkin Person 
No, they don’t, for IQ is not supposed to be a demographic variable but rather a mental health one. So these tests must have reference samples that are considered healthy. Otherwise it would underestimate the severity of age related mental conditions and prevent those who need medication or special care to get it.
“If Modern Humans Are So Smart, Why Are Our Brains Shrinking?”
http://discovermagazine.com/2010/sep/25-modern-humans-smart-why-brain-shrinking
What are your feelings on this ?
When the ice age ended, we no longer needed to be as smart to survive, so oversized brains became a liability because they’re so metabolically expensive, physically burdensome, hazardous to child birth & prone to overheating. As a result, a lot of big brained folks died, leaving smaller brained folks as the survivors.
Also, once we created tools, we no longer had to be as robust. As we became more gracile, brain size shrunk because we had less muscle mass to coordinate.
Lastly, once we developed agriculture, there was mass malnutrition that further shrunk the body and brain.
“When the ice age ended, we no longer needed to be as smart to survive,”
“Lastly, once we developed agriculture, there was mass malnutrition that further shrunk the body and brain.”
Shrinking brain size occured everywhere in the world and in non-agricultural societies too.
I personally suscribe more to the human self-domestication hypothesis as similar patterns of brain size reduction have been observed in other domesticated species.
Moreover, I don’t believe that a larger brain causes a greater intelligence (or at least IQ test performance). The correlation between IQ and brain size is said to be 0.3 – 0.4. That seems very moderate.
In my opinion, this correlation is rather due to a common factor that both causes further brain growth and better test performance. This common factor is probably health status (including nutrition and optimal and balanced development) which has the effect of pushing brain growth up to its genetic potential while it is also associated with lifestyles and socio-economic environments that increase test performance.
You can notice that I mention the idea of a genetic potential for brain size. Don’t get me wrong though. I believe that your genetic potential for brain growth doesn’t define your intelligence, only the realization of it does. It would mean that a small brain that has reached 100% of its growth potential is probably smarter than a larger brain that only has fulfilled 70% and the latter would be as smart, not smarter, when it reaches 100%. Then, the reason why people don’t reach the brain size that is encoded in their DNA is most likely environmental.
Another of my current established point of views is that IQ is not a biologic measurment (it’s not even a measurement). I have many reasons to believe that.
1- IQ exists nowhere in the universe. There are no cells of IQ, no hormone of IQ, no genes of IQ, and I would even dare saying there is no organ of IQ since neuroscientists are not really able to identify what happens in the brain when someone is taking an IQ test and neither are they able to say what biologic process influence performance.
2- IQ is trainable, and testing to the IQ test doesn’t change anything in people’s cognitive abilities in real life, they only become better IQ test takers. So I come to the conclusion that different lifestyles and environments provide indirect training for IQ test performance, which explains various socio-economic and ethnic correlates of IQ. But most of the variation (between individuals, groups and eras) is mostly mere artificial test readiness. Obviously, a part of the variation maybe biologic. a stunted, exhausted, injured, traumatized or stressed brain may not be doing very well on an IQ test and in life. But if we were to compare people who have reached their full genetic potential for brain fitness, the remaining variation would essentially be the artificial test readiness mentionned above.
Why did brain size triple as apes evolved into humans if it doesn’t cause intelligence?
Well, the brain size advantage that humans have over apes or earlier homininds has to be relativized.
1- because a big brain causes overheating in hot climates where most of them live. Moreover, these species have fur which further increase body temperature. These two elements combined may have put double pressure to favor smaller brains.That’s for the metabolic part.
2- It is hard to know if apes and archaic humans met their nutritional needs like we do.
3- Brain size reached its peak in Neanderthals and Archaic homo sapiens while most of humanity’s accomplishments occured when brain size was shrinking.
4- Brain size doesn’t cause intelligence, it’s a fact otherwise, the correlation between brain size and the most accurate measurment or intelligence would be 1, but it’s not. The most probable explanation is that something that contributes to increasing brain size has an effect on IQ test performance, but brain size alone is not a strong indicator of IQ test performance.
Well, the brain size advantage that humans have over apes or earlier homininds has to be relativized.
1- because a big brain causes overheating in hot climates where most of them live.
But that doesn’t explain why even tropical humans have roughly triple the brain size of apes
Moreover, these species have fur which further increase body temperature.
Good point. Now that you mention it, perhaps one reason humans lost fur was so our brains could get even bigger without overheating
2- It is hard to know if apes and archaic humans met their nutritional needs like we do.
They evolved to function on the hunter-gatherer diet their bodies had millions of years to adapt to, so they were probably better nourished than most humans today
3- Brain size reached its peak in Neanderthals and Archaic homo sapiens while most of humanity’s accomplishments occured when brain size was shrinking.
That just shows the correlation isn’t perfect. But overall the pattern is strong. Humans are the smartest animal on Earth & have the largest brain relative to body size of any animal. Among humans, those races with the largest brains have invented and discovered the most. Even among mice, there’s a 0.48 correlation between brain size and maze solving speed. Experiments where mice have been bred for greater maze solving talent results in bigger brained mice.
4- Brain size doesn’t cause intelligence, it’s a fact otherwise, the correlation between brain size and the most accurate measurment or intelligence would be 1, but it’s not.
The strength of the correlation has nothing to do with whether it’s causal or not. These are independent concepts. You can have a perfect correlation that is not causal and you can have an extremely small correlation that is entirely causal.
The most probable explanation is that something that contributes to increasing brain size has an effect on IQ test performance, but brain size alone is not a strong indicator of IQ test performance.
Why not just go with the obvious explanation. As Michael Hart noted, bigger muscles lift more weight, bigger hearts pump more blood, why wouldn’t bigger brains process more information?
“But that doesn’t explain why even tropical humans have roughly triple the brain size of apes”
My whole claim is that the combination of tropical environment + fur may have favored smaller brains.
“They evolved to function on the hunter-gatherer diet their bodies had millions of years to adapt to, so they were probably better nourished than most humans today”
I doubt it. I believe that hominids before homo erectus had no serious intellectual advantage in competing for resources against fierce animals such as lions, bears, wolves, snakes… On the other hand, gathering plants and insects is a very unstable source of food. A child born in the African dry season probably suffered severe under-nourishment and dehydratation at the most crucial period for brain growth. And considering the energetic costs of the hunter-gatherer’s lifestyle his nutritional needs would probably be similar to that of a professional athlete. By the way, it is also known that early intense physical activity stunts growth.
“That just shows the correlation isn’t perfect”
Indeed…
“Among humans, those races with the largest brains have invented and discovered the most.”
Are you talking about the brilliant Inuit civilization or refering the Chinese colonisation of Europe and the Americas ?
No, pre-modern civilization is well known to have emerged under specific ecologic conditions that favor and sustain high population density that leads to the formation of urban settlements fed by agricultural surpluses. These conditions are:
-Temperate climate: agriculture thrives in climates that are neither too cold or too hot and that provide appropriate rainfall.
-Proximity of drinkable water: Allowing irrigation if rainfall is not sufficient and providing water to sustain human life and activity.
-Fertile soils: to optimize agricultural output
-Low disease load: Humans need to live free of diseases that threaten their lives, devlopment and productivity. Tropical lowlands are the most affected by endemic deseases whereas temperate and cold environments are less.
-Narrow terrains: The fuel of civilization is population, not in terms of quality as HBDers would like to believe but of mere quantity. For that reason, flat continental masses which favored population dispersal (North America, South America out of the Andes, Sub-Saharan Africa, Northern Eurasia and Australia) have had slower human development. In addition to the fact that continentality often makes climatic conditions harsher.
On the contrary, peninsulas, isthmus, small islands, closed valleys and montainous plains favor human concentration. Never wondered why Italy and Greece were civilized before France and Germany and then surpassed by the two latter ? It’s simple, the ancestors of the French and Germans had it more difficult to populate their lands than those of the Greeks and Italians. But once France and Germany have reached population densities that could lead to the emergence of cities, they found themselves totalling larger population, on larger areas and somewhat better ecologic conditions allowing them to become the new centers of Western civilization.
All these factors of civilization are well known and completely independant of race. See the difference between the Aztecs and Canada’s first Nations… I’m not supposed to teach you such things and if you had known before, you would not find yourself so stupid when you wonder why the Nubians built pyramids when the Celts lived in huts…
“The strength of the correlation has nothing to do with whether it’s causal or not. ”
So I am wrong to belive that if something is the sole cause of the something else, the correlation between the two is 1. Anyway, If you applied this argument to yourself, you would be much more cautions with regard to the conclsions you reach from correlations that you are quick to describe as undisputably causal.
“bigger muscles lift more weight, bigger hearts pump more blood, why wouldn’t bigger brains process more information?”
You see, my samsung galaxy S7 processes more information than the payphone at the corner of the street. Neuroscientists tend to think that what matters the most in the brain is the qualitative aspect, not the quantitative one. Brain activity deals more with chemical reactions than physical handeling of material things. If intelligence was a fluid or a mass that the brain had to carry and store, size would probably matter a lot but it is not the case.
“bigger muscles lift more weight, bigger hearts pump more blood, why wouldn’t bigger brains process more information?”
I forgot to mention: bigger eyes are nearsighted. Size doesn’t make things more efficient when it comes to complex nervous system matters…
My whole claim is that the combination of tropical environment + fur may have favored smaller brains.
And yet despite smaller brain size being favored in these tropical furry creatures, brain size tripled in just 4 million years. This shows the intellectual advantage of huge brains was so great, it trumped the fact that smaller brains cool more easily.
On the other hand, gathering plants and insects is a very unstable source of food.
Then show me the studies where chimps raised in captivity with good nutrition have much bigger brains than chimps in the wild
Are you talking about the brilliant Inuit civilization or refering the Chinese colonisation of Europe and the Americas ?
Of the six great civilizations to emerge independently, three were created by Mongoloids & three were created by Caucasoids. The two biggest brained races. Indeed scholar Michael Hart argues that not a single major invention of the last 20,000 years was made in sub-Saharan Africa.
No, pre-modern civilization is well known to have emerged under specific ecologic conditions that favor and sustain high population density that leads to the formation of urban settlements fed by agricultural surpluses.
No one is suggesting that a large brain population was the only condition necessary for civilization to emerge, but it does increase the odds. Do you understand the difference?
you wonder why the Nubians built pyramids when the Celts lived in huts…
I don’t wonder about that because the Nubians did not build the pyramids
So I am wrong to belive that if something is the sole cause of the something else, the correlation between the two is 1.
No one is suggesting that brain size is the “sole” cause of intelligence. It’s one of many causes, thus an imperfect correlation.
You on the other hand are arguing that imperfect correlation is because both brain size & IQ reflect health, which is nonsense because the correlation has been repeatedly found in healthy populations
You see, my samsung galaxy S7 processes more information than the payphone at the corner of the street. Neuroscientists tend to think that what matters the most in the brain is the qualitative
All else being equal, large computers are more powerful than small ones
Brain activity deals more with chemical reactions than physical handeling of material things. If intelligence was a fluid or a mass that the brain had to carry and store, size would probably matter a lot but it is not the case.
Neurons take up physical space. The greater the number of neurons, the more connections in the brain, on average
“And yet despite smaller brain size being favored in these tropical furry creatures, brain size tripled in just 4 million years. This shows the intellectual advantage of huge brains was so great, it trumped the fact that smaller brains cool more easily.”
On the other hand, brain size experienced a 20% decrease in the last 20,000 years when most of humanity’s accomplishments occured. So as strong as it may seem, brain size seems not to equal brain efficiency.
“Of the six great civilizations to emerge independently, three were created by Mongoloids & three were created by Caucasoids.”
Civilization emerged faster in environments that favored certain phenotypes. However, you can’t percieve this as the consequence of a collective racial effort to achieve civilization. You can’t credit the Slavs for the accomplishments of the Babylonians or the Choctaws for that of the Mayas.
“Indeed scholar Michael Hart argues that not a single major invention of the last 20,000 years was made in sub-Saharan Africa.”
https://en.wikipedia.org/wiki/Michael_H._Hart .
Do you consider that man as a serious authority when it comes to world history ?
The mainstream consensus is that Sub-Saharan reached the Iron age stage of technological development independently of external contributions.
“No one is suggesting that a large brain population was the only condition necessary for civilization to emerge, but it does increase the odds.”
Nothing shows that different races living in natural environments that are similarly favorable to the development of civilization have demonstrated different abilities for organization and invention. For instance, Brazil and the Congo are two almost identical natural environments inhabited by vastly different races. If we compare the indigenous pre-colonial populations of the two areas, there is a slight civilizational advantage for the indigenous of Central Africa who are sedentary metal-working agriculturalists originally from West Africa whereas the natvie brazilians were semi-nomadic hunter-gatherers, just like the Pygmies and Bushmen who are the true aboriginals of the southern half of Africa.
“I don’t wonder about that because the Nubians did not build the pyramids”
Pardon me ?
https://en.wikipedia.org/wiki/Nubian_pyramids
“You on the other hand are arguing that imperfect correlation is because both brain size & IQ reflect health, which is nonsense because the correlation has been repeatedly found in healthy populations”
Yes, health and lifestyle, and that makes sense. Health is a broad and loose concept, you can be well fed or even overfed and still suffer deficiencies for nutrients that matter a lot for brain fitness.
“Neurons take up physical space. The greater the number of neurons, the more connections in the brain, on average”
Neurotransmission has nothing to do with the number of neurons and neural density is not the same in all parts of the nervous system. I won’t pretend I’m an expert in this field but neither should you.
On the other hand, brain size experienced a 20% decrease in the last 20,000 years when most of humanity’s accomplishments occured.
Actually it’s only about a 3% decrease when you adjust for the reduction in body size.
.
Do you consider that man as a serious authority when it comes to world history ?
Just because you disagree with his politics doesn’t mean he’s not an expert. He’s a best-selling author on World history and has more degrees than a thermometer. Yes, I would consider him an authority
The mainstream consensus is that Sub-Saharan reached the Iron age stage of technological development independently of external contributions.
I don’t see a consensus:
http://johnhawks.net/weblog/reviews/archaeology/neolithic/africa/ironworking-africa-pringle-2009.html
Nothing shows that different races living in natural environments that are similarly favorable to the development of civilization have demonstrated different abilities for organization and invention.
Blacks didn’t independently create civilization anywhere. They created it nowhere in all of sub-Saharan Africa. If we expand the definition of black to include the Australoids, then we see that in addition to failing to create a civilization anywhere in all of sub-Sahara, they failed to create one in Asia or Australia too. There’s even evidence that the Australoids were in the Americas before the Mongoloids were, and they failed to create civilization there too. That’s four out of four continents where blacks failed to create civilization.
To quote Paul Broca:
A prognathous [forward-jutting] face, more or less black color of the skin, woolly hair and intellectual and social inferiority are often associated, while more or less white skin, straight hair and an orthognathous [straight] face are the ordinary equipment of the highest groups in the human series (1866, p. 280)….A group with black skin, woolly hair and a prognathous face has never been able to raise itself spontaneously to civilization
Pardon me ?
I thought you meant THE pyramids.
Yes, health and lifestyle, and that makes sense. Health is a broad and loose concept, you can be well fed or even overfed and still suffer deficiencies for nutrients that matter a lot for brain fitness.
The evidence that brain size has an independent effect on intelligence is so overwhelming that by continuing to deny it, you disqualify yourself as a serious person. You might as well be a creationist or a flat-earther.
I don’t think this is a reasonable way to look at it. High death rate at 85 is directly comparable to high infant mortality rates in any era other than our own. Whether to include demented seniors is the same question as whether to include mentally handicapped/damaged people in any other age group (I disagree on including them).
I don’t think this is a reasonable way to look at it. High death rate at 85 is directly comparable to high infant mortality rates in any era other than our own. Whether to include demented seniors is the same question as whether to include mentally handicapped/damaged people in any other age group (I disagree on including them).
But the problem is, if someone gets an IQ score in the 90 percentile at age 20, and then gets an IQ score in the 90 percentile again at age 85, they are falsely under the impression that they have maintained their cognitive rank relative to others of their birth cohort. But in actual fact, their cognitive rank has gone up because a lot of the people they used to be smarter than are no longer included in the reference group because of death or dementia. If those people were to be included, the IQ might be in the 99 percentile for age.
The analogy I would make is that you take an IQ in the fifth grade, and told you scored at the class average. Then as a PhD student, you take the same test again and are told you are in the bottom 2% of the class. It’s not that your ability relative to your peers has changed, but rather that your peers themselves have changed.
To avoid such confusion, it might be better to keep the reference group constant for the entire life span.