Does brain size matter?

[leopold]

The point is that smart people generally have larger brains.

the point is that i used your own sources to say they don't know what causes bigger brains nature or nurture. but one thing is clear learning is an evironmental process.

 

[francois]

It remains to be determined what the contribution of nature and nurture are to this cerebral size relationship with intelligence, Witelson said.

That's not saying the same thing. It's likely that, as in most things, it's a combination of both nature and nurture. Like anything else, it's not a case of either/or as you seem to think it is. Under normal conditions, I'm guessing genetics play a big role in brain size, similar to how genetics play a role in a person's height, proportions, bone structure, craniometry, whatever. I'll see if I can back any of that up in later posts.

Anyway, the point isn't what causes the differences in brain sizes. The point is that smart people generally have larger brains. Didn't I make that clear in the first post of the thread?

 

[leopold]

first of all i can't imagine why this subject is so interesting to you.
second brain size is not a measure of intelligence, it can't be or some of the animals i listed would totally eclipse humans on the intelligence scale.

 

[Ophiolite]

The point is that smart people generally have larger brains.

Let's hear it for the Neanderthals.

 

[francois]

Of course, they're not people. They're neanderthals.

Similar to how cetaceans are cetaceans. Similar to how false killer whales are false killer whales. Same as how African elephants are African elephants.

They are a different animal with a different brain.

Homo sapiens, however, have very similar brains compared to other homo sapiens. It's common sense, I think. But it's amazing the people who cannot understand this. Baffling really.

 

[francois]

first of all i can't imagine why this subject is so interesting to you.
second brain size is not a measure of intelligence, it can't be or some of the animals i listed would totally eclipse humans on the intelligence scale.

I'll explain why I find it interesting. One reason is because it's controversial. The field of intelligence, if one looks, is like a Jerry Springer set. Idiots in the media and other affiliations--people who don't understand science or know how to make cogent arguments--attack scientists who say things that offend them. It is a highly politicized field because the truth offends most people.

Also other scientists, like Stephen Gould, author of the Mismeasurement of Man, illustrates what happens when a "scientist" says something the average idiot wants to hear. Everybody praises him, except for people who understand his "science" and his methods. It's fascinating. As we all know, universities are highly liberal institutions. In about the month I've been attending my college, I've heard teachers make mention of The Mismeasurement Of Man about three times.

What do people think about his book? It's cut down the center. Nothing but praise and adulation from people from magazines and journals--people don't understand science, aren't interested in science, and are extremely receptive of information they like.

However, all of his colleagues think his book stinks. Everybody in the scientific community thinks it stinks and believe he is slanting his information to serve some political agenda.

In other words, scientists hate his book with a passion, where non-scientists love it. I find this stuff interesting, and that partly explains why I'm so interested in this stuff. The controversy.



Other than that, intelligence is a pretty important thing, isn't it? I've always been interested in the way things work. When I was 12 or so, my uncle bought me the book, "How things work," which I treasure to this day. It told me how hydraulics work, how batteries work, refrigerators, car breaks, internal combustion engines, etc. And it did it with cool illustrations with the aid of a friendly and charming mammoth. He was pretty great in his own right. So yeah, I'm interested in what makes us intelligent. What's so wrong with that?



For your other point. I'd beg to differ. Brain size is an indicator of intelligence. It is crude, however. My point is not that False killer whales have huge brains and are not as intelligent as humans. My only point is that smart people tend to have large brains. If you disagree with this statement, disprove it.

 

[leopold]

i have looked online for factors affecting inelligence and various ways of measuring intelligence, none involve measuring brain size.

brain size alone cannot be a reliable indicator of intelligence, if it were then the neanderthals ohpiolite mentioned and the false blue whale would have far superior intelligence than we do.

i suggest that you look into the real reasons of intelligence such as heredity and environment.

 

[Ophiolite]

In another thread, at another time, I believe I may have remarked that I wished to convince you that I was right and the poster I was debating with was wrong. I said my reason for this was a desire to be thought of positively by yourself, as you seemed to be an intelligent and knowledgeable poster.

I wish to wholly withdraw that sentiment. Clearly, I was mistaken.

Of course, they're not people. They're neanderthals.

Really. Not people.
A species so similar to ours that they almost certainly interbred with us. Not people.
A species with an anatomy so similar that were one to walk down the high street of any town in Europe, dressed in typical western clothes, he would not attract a second glance. Not people.
A species so similar that, to their cost, they occupied much the same ecological niche as homo sapiens sapiens. Not people.

The probability is, based upon a reasoned study of their lifestyle, that they were not as mentally sophisticated as us. (Let's call that intelligence.) That likely was not dependent upon their brain size, but upon their brain structure..

Homo sapiens, however, have very similar brains compared to other homo sapiens. It's common sense, I think. But it's amazing the people who cannot understand this. Baffling really.

The important correlation is between brain size and body mass. It takes more brain to control a larger body. The close similarity between homo sapiens and homo neanderthalis makes comparisons wholly valid.
Your reliance on common sense in a scientific discussion brings into serious question your claim to be familiar with science and its techniques. Why would anyone appeal to common sense to support their argument? Baffling really.

 

[francois]

In another thread, at another time, I believe I may have remarked that I wished to convince you that I was right and the poster I was debating with was wrong. I said my reason for this was a desire to be thought of positively by yourself, as you seemed to be an intelligent and knowledgeable poster.

The hidden assumption here is that you think I should care about what you think of me. This is erroneous.

I wish to wholly withdraw that sentiment. Clearly, I was mistaken.Really. Not people.
A species so similar to ours that they almost certainly interbred with us. Not people.
A species with an anatomy so similar that were one to walk down the high street of any town in Europe, dressed in typical western clothes, he would not attract a second glance. Not people.
A species so similar that, to their cost, they occupied much the same ecological niche as homo sapiens sapiens. Not people.

My mistake. They are humans, and thus, they are people.

Human:
1. A member of the genus Homo and especially of the species H. sapiens.
Neanderthal:
Homo neanderthalensis

I was under the conception that humans are Homo sapiens. I made a simple semantic error. Shoot me.

The probability is, based upon a reasoned study of their lifestyle, that they were not as mentally sophisticated as us. (Let's call that intelligence.) That likely was not dependent upon their brain size, but upon their brain structure..The important correlation is between brain size and body mass. It takes more brain to control a larger body. The close similarity between homo sapiens and homo neanderthalis makes comparisons wholly valid.

There's a problem with your reasoning here. You agree that neanderthals were much less intelligent than Homo sapiens. The neanderthal's brains were about the same size as Homo sapiens, but their bodies were smaller, so the neanderthal brain was larger compared to their bodies than Homo sapiens. So obviously, brain structure plays an important role here.

If the brains of Homo sapiens and Homo neanderthalensis are so structually different, how do you figure that making comparisons between the two is wholly valid?

I'm saying the general structural variations among brains of among Homo sapiens are insignificant compared to the structural differences between a given Homo sapien and a given neanderthal. Neanderthals have different brains. That's all I'm saying.

Disprove that smart humans--no, Homo sapiens--generally have larger brains.

 

[Ophiolite]

The hidden assumption here is that you think I should care about what you think of me. This is erroneous.
.

It may be your assumption. It is certainly not mine. I was making the point, rather directly, perhaps to the point of rudeness, that at one time I would have appreciated your appreciation of me. That was based upon a faulty judgement of your character.

I made a simple semantic error.

Contrary to popular belief, a belief to which you appear to subscribe, a semantic error is one of the worst kinds of error. In short, you did not understand what you were saying; and there was no correlation between what you meant (which was wrong) and what you said (which was also, but independently, wrong). This simple semantic error has swept away that particular argument. I say again, let's hear it for the neanderthals. Clearly, from their larger brain size, so much smarter than us.

My only point is that smart people tend to have large brains. If you disagree with this statement, disprove it.

Again you demonstrate your ignorance of scientific method. There is nothing wrong with that unless you try to use that ignorance to justify your thesis. You are the one making the unconventional claim. It is up to you to demonstrate the validity of that claim.

 

[cole grey]

Homo sapiens, however, have very similar brains compared to other homo sapiens. It's common sense, I think. But it's amazing the people who cannot understand this. Baffling really.

I have explained this to you.
That you fail to understand is "baffling".

Human brains ARE very similar, compared to a mouse's for example, and yet, the differences can be striking, yet produce no measurable difference in "intelligence". The huge differences between men and women, in MRI scans, and the negligible differences in their IQ scores, should explain what this means.

Very different brains are capable of similar intelligence scores. Proven fact.
Smaller, bigger, structurally different, the guy with a hemispherectomy, et. al.

you didn't do your homework yet,
Homework for you- design a study which would provide some evidence for your idea that large brains are a causal factor.

 

[francois]

http://www.ctv.ca/servlet/ArticleNe...ze_intelligence_20051223/20051223?hub=SciTech

Study in Toronto, Canada measures the weight and other metrics of 100 brains of people who have done extensive IQ tests.

"What is very clear is that there is a correlation between brain size and intelligence, particularly verbal ability," said Witelson,

http://lib.stat.cmu.edu/DASL/Stories/BrainSizeandIntelligence.html
University students find smarter people have larger brains.

http://www.futurepundit.com/archives/003188.html

These results are consistent with lots of other studies which found a positive correlation between brain size and intelligence. Bigger is better.

http://en.wikipedia.org/wiki/Neuroscience_and_intelligence

Brain size is a rudimentary indicator of the intelligence of a brain, and many other factors affect the intelligence of a brain. Higher ratios of brain to body mass may increase the amount of brain mass available for more complex cognitive tasks.

http://health.dailynewscentral.com/content/view/1102/0

For all age and sex groups, it is now very clear that brain volume and intelligence are related, McDaniel said.

http://www.news-medical.net/?id=11121

People with bigger brains are smarter than their smaller-brained counterparts, according to a study conducted by a Virginia Commonwealth University researcher published in the journal "Intelligence."

Now. I'm not saying large brain size is what causes large brained people to be smarter. But it's likely that larger brains facilitate other things to happen. Smarter people--no, Homo sapiens--generally have larger brains.

Who can dispute this?

Cole gray, you made mention that men are the same intelligence as women. Well. Not quite.

The Ankney-Rushton anomaly presents a major problem for the accepted view that there is no sex difference in general intelligence. Three conclusions are proposed for the resolution of the anomaly. (1) It cannot be solved by opaque analogies with body-brain ratios in fish and birds, according to which human males are like birds, with large brains relative to bodies, while human females are like fish, with small brains relative to bodies (Mackintosh). Nor can it be solved by the contention that the female brain is more efficient than the male, providing a compensation for its smaller size (Jensen). (2) An important key to the resolution of the Ankney-Rushton anomaly lies in the recognition that the faster maturation of girls up to the age of approximately 16-years-old accelerates their cognitive development and compensates for their smaller brain size. It follows that the sex differences in abilities appear most clearly among adults in whom the maturational processes are complete. When this starting point is adopted, the resolution of the anomaly becomes clear. It is that males do have higher mean IQs than females by approximately 4 IQ points, commensurate with their larger average brain size. This conclusion holds whether general intelligence is defined as the sum of the verbal comprehension, reasoning and spatial group factors (Lynn), as fluid intelligence or reasoning ability (Mackintosh, Jensen), or as Spearman's g measured from the first principal component or as the global IQ obtained from standard intelligence and aptitude tests (Jensen), so long as these fulfil the conditions stipulated by Jensen. (3) The resolution of the Ankney-Rushton anomaly among children and young adolescents up to the age of 16 is a more difficult problem and requires further attention. What is needed is the breakdown of sex differences on each major ability for each year of age. A model for the required method of analysis is provided by Alexopoulos (1996) in his study of sex differences in reasoning ability among 13-18-year-olds in Greece. Aggregation of the results showed no sex difference, but analysis of the differences for each year showed that females obtained significantly higher IQs at age 13, there were no sex differences at ages 14-15, and that males had higher IQs at ages 16-18. These intelligence differences parallel the increasing male advantage in brain size over these years. Further analyses of this kind will show how far the developmental theory can explain sex differences in intelligence in childhood and early adolescence.

Sorry I don't have a source available. It's through my school's proxy.

http://news.bbc.co.uk/1/hi/education/4183166.stm

Academics in the UK claim their research shows that men are more intelligent than women.

http://www.livescience.com/humanbiology/060908_brainy_men.html

Controversial stuff. Exciting!

 

[spuriousmonkey]

A real study and not a news story.
Neurosci. 2006 Oct 4;26(40):10235-42.

Genetic contributions to human brain morphology and intelligence.

Hulshoff Pol HE, Schnack HG, Posthuma D, Mandl RC, Baare WF, van Oel C, van Haren NE, Collins DL, Evans AC, Amunts K, Burgel U, Zilles K, de Geus E, Boomsma DI, Kahn RS.

To explore the common genetic origin of focal GM and WM areas with intelligence, we obtained cross-trait/cross-twin correlations in which the focal GM and WM densities of each twin are correlated with the psychometric intelligence quotient of his/her cotwin. Genes influenced individual differences in left and right superior occipitofrontal fascicle (heritability up to 0.79 and 0.77), corpus callosum (0.82, 0.80), optic radiation (0.69, 0.79), corticospinal tract (0.78, 0.79), medial frontal cortex (0.78, 0.83), superior frontal cortex (0.76, 0.80), superior temporal cortex (0.80, 0.77), left occipital cortex (0.85), left postcentral cortex (0.83), left posterior cingulate cortex (0.83), right parahippocampal cortex (0.69), and amygdala (0.80, 0.55). Intelligence shared a common genetic origin with superior occipitofrontal, callosal, and left optical radiation WM and frontal, occipital, and parahippocampal GM (phenotypic correlations up to 0.35). These findings point to a neural network that shares a common genetic origin with human intelligence.

 

[leopold]

Smarter people--no, Homo sapiens--generally have larger brains.

Who can dispute this?

http://www.physorg.com/news10312.html

 

[spuriousmonkey]

That is indeed an interesting link Leopold.

It reminds me of the Einstein data. The areas involved in mathematical thinking were enlarged. That of course raises the question if they always had been enlarged or that merely his interest in the area exaggerated the enlargment!

If one would measure the brains of people who had differences in education one would find different sizes merely due to stimulation differences.

If one would measure similar intellectual surroundings one would find similar sizes?

This notion of growth of a stimulated brain shows that the size of the brain is not a good marker for studying differences within a population.

It also reminds me of the weird phenomenon that siblings often have a rather comparable IQ, till they leave the house and venture out on their own.

This also reminds me of an earlier thread:

http://sciforums.com/showthread.php?t=57416

http://dev.biologists.org/cgi/content/full/133/18/3671

Human brain tissue was extracted from living individuals undergoing surgery connected to epilepsy. Tissue slices were obtained from different areas of the brain and studied in a tissue culture system.

Different assays were used to determine the presence of progenitors. And they actually managed to isolate and expand astroglial cell lines from these epileptic temporal lobe resections. These cell lines showed characteristics progenitor cells.

summary

The isolation and expansion of human neural cell types has become increasingly relevant in restorative neurobiology. Although embryonic and fetal tissue are frequently envisaged as providing sufficiently primordial cells for such applications, the developmental plasticity of endogenous adult neural cells remains largely unclear. To examine the developmental potential of adult human brain cells, we applied conditions favoring the growth of neural stem cells to multiple cortical regions, resulting in the identification and selection of a population of adult human neural progenitors (AHNPs). These nestin+ progenitors may be derived from multiple forebrain regions, are maintainable in adherent conditions, co-express multiple glial and immature markers, and are highly expandable, allowing a single progenitor to theoretically form sufficient cells for 4x107 adult brains. AHNPs longitudinally maintain the ability to generate both glial and neuronal cell types in vivo and in vitro, and are amenable to genetic modification and transplantation. These findings suggest an unprecedented degree of inducible plasticity is retained by cells of the adult central nervous system.

As in compared to rodent brains.

Neuronizing AHNPs frequently display an `asteron' hybrid phenotype, similar to recent findings in cultured rodent neural cells (Laywell et al., 2005; Okano-Uchida et al., 2004). Whereas those studies report a neuron-to-glia transdifferentiation, the transition reported here represents a glia-to-neuron commitment, suggesting the isolation of conditions (Ronnett et al., 1990) that promote the phenotypic alteration of widely distributed endogenous AHNPs may be possible.

Interesting isn't it!

As such nobody understood it, but I gave the translation a post later:

The basic message is that human brains differ from rodent brains in that they have more regenerative capability.

Ironically most of the research is done on mice of course. And all data is extrapolated to humans.

This is done in all areas of biological research.

Now if we substitute regeneration for adaptive restructuring and growth. The human brain has evolved to be more flexible than a mouse brain. Is this to allow for the growth and restructuring of the brain under environmental influences?

The early humans overcoming their environment by extreme adaptation, starting at the level of adaptive restructuring the brain due to environmental conditioning.

It would be nice to compare the brains of opportunist species with other ones in this respect.

 

[francois]

http://www.physorg.com/news10312.html

That's interesting stuff, Leopold99. Now I wonder. Is increasing brain mass a good thing?

 

[leopold]

That's interesting stuff, Leopold99. Now I wonder. Is increasing brain mass a good thing?

your questions went like this:
does brain size matter?
can you dispute that big brains mean more intelligence?
is brain mass a good thing?

i have already answered the first two questions.
it seems you aren't going to stop unless someone says 'yes, brain size matters'.

 

[francois]

your questions went like this:
does brain size matter?
can you dispute that big brains mean more intelligence?
is brain mass a good thing?

i have already answered the first two questions.
it seems you aren't going to stop unless someone says 'yes, brain size matters'.

That's because you didn't disprove me. All you did was disagree. You never used a cogent argument against mine. So the question remains. Is it not true that smart people generally have larger brains?

 

[leopold]

Is it not true that smart people generally have larger brains?

is it not true that the more churches a community has the more murders are commited in that community?

you are equating big brains with intelligence.
i have shown with my link that 'big brains' can result from meditation.

but let's forget all of that, i am axious to see where you go with this.
yes, big brains mean more intelligence.
now what?

 

[francois]

is it not true that the more churches a community has the more murders are commited in that community?

I have no idea. I really know nothing about that sort of thing.

you are equating big brains with intelligence.

Indeedy doo.

i have shown with my link that 'big brains' can result from meditation.

Not really. The link showed that meditation can have the effect of growing brain mass, similar to how musicians and jugglers can. It doesn't say meditation can result in a 'big brains', as you say.

but let's forget all of that, i am axious to see where you go with this.
yes, big brains mean more intelligence.
now what?

Now what? Now nothing. If people reading this thread now agree that smarter people have larger brains, then the thread has succeeded in its goal. I said earlier that it annoyed me that some people don't think there is a relationship between brain size and IQ. So this is just a thread that addresses that.