Does brain size matter?

francois

Schwat?
Registered Senior Member
Well, what do you think, folks?

Is brain size at all important? Studies seem to indicate that it does matter. Let's not make this an argument about opinions. Let's just compare sources and see if we can make any logical and meaningful deductions from them. This can be a thread where we can pool information together and see how it all relates to nature. I'll begin posting sources a bit later.
 
Organization is much more important than size. You can remove all of one-half of a young child's brain* (forget how young, but perhaps 2 year old or less) and no one will notice any deficiency a year later. Also, Anatol France (spelling may not be correct) was quite an intellect but had small head. When he died, his brain weight was measured - 900 grams - very much less than normal. I think, but do not know, that a sperm whale's brain is many times more massive than a humans. Compared to humans, small bats have greater brain to body weight ratio. They can do acoustical processing with it that man cannot match with all the computers in the world. (Where I worked, the was a group, about 60 people, in charge of keeping US subs secure and learning how to pull weak soviet sub sounds out of the much stronger background sea sounds. Most of them would agree that they were "acoustical idiots" compared to a common bat, which can tell what type of moth his echo is returning from 20 or more feet away. - Some must taste better than others as the bat makes his selection from far away and adjust his "chirp" and pulse repetition rate to optimize data return from it!
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*This is sometimes necessary for refractory Status Epileptus.
 
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Thanks for the response, Billy T!

Indeed organization is more important than size. But what about within a species? Surely there are some structural differences in the brains of men and women. But even more surely, those differences are insignificant compared to the structural differences between those of a human and, to use your example, a sperm whale. Within a species, because brain structure is generally very consistent, I think brain size plays an important role in an organisms intelligence.

http://en.wikipedia.org/wiki/Brain_size_and_intelligence
A related study has reported that the correlation between brain size (reported to have a heritability of 0.85) and g is 0.4, and that correlation is mediated entirely by genetic factors (Posthuma et al 2002).

http://lib.stat.cmu.edu/DASL/Stories/BrainSizeandIntelligence.html
Here, the correlation was found among introductory psychology students. There is a correlation of .51.

http://www.futurepundit.com/archives/003188.html
Brain size matters for intellectual ability and bigger is better, McMaster University researchers have found.

http://www.ctv.ca/servlet/ArticleNe...ze_intelligence_20051223/20051223?hub=SciTech
Study in Toronto, Canada finds correlation of IQ and brain size in a sample of 100.
Bigger is better when it comes to brain matter, says a leading neuroscientist.
"What is very clear is that there is a correlation between brain size and intelligence, particularly verbal ability," said Witelson

There is absolutely zero convincing evidence that brain size does not play an important role in intelligence--at least among humans.
 
can remove all of one-half of a young child's brain* (forget how young, but perhaps 2 year old or less) and no one will notice any deficiency a year later. *This is sometimes necessary for refractory Status Epileptus.
Francois - did you even see this?
http://en.wikipedia.org/wiki/Hemispherectomy said:
re- hemispherectomy
Most patients who have undergone this procedure will have neurons from the remaining hemisphere take over the tasks from the lost hemisphere by making new neural connections. One case, demonstrated by Smith & Sugar, 1975; A. Smith 1987, showed that one patient with this procedure had completed college, had attended graduate school, scored above average on intelligence tests. Another study done by Johns Hopkins University medical team, reflecting on 58 child hemispherectomies they performed, all the reports showed that most children continued on with little or no change to their memory, personality, and humor after removal of either brain hemisphere. (Vining & Others, 1997)
Oh my god, this is just beyond reality here. You think a little brain size issue is going to stand in the way of the human body? That is crazy.
The guy mentioned here scored above average on intelligence tests, after a hemispherectomy, meaning he had half of his brain either removed or disconnected. I mean, I was talking about the capacity of the brain to re-create its functionality after a little bit of damage, but this example proves my idea of the brain's adaptability. Your idea that the brain must be structurally similar enough, within all members of a species, to allow brain size to account for any substantial part of an iq score is obviously wrong.
 
Well, what do you think, folks?

Is brain size at all important? Studies seem to indicate that it does matter. Let's not make this an argument about opinions. Let's just compare sources and see if we can make any logical and meaningful deductions from them. This can be a thread where we can pool information together and see how it all relates to nature. I'll begin posting sources a bit later.


The notion that brain size/body size ratio is correlated to intelligence on a phylogenetic level is not disputed. You learn that in high school biology class.

That's right. You failed to make a proper question.

See discussion here:

http://sciforums.com/showthread.php?t=57867

It's all been said already.
 
Francois - did you even see this?
Yes, I read it. And omg, you're so right! This only proves that we don't even need the whole brain! Isn't it weird that we have brains with two hemispheres when it's so obvious when we only need one to function! Ah, mother nature. What a dumb bitch.

Your idea that the brain must be structurally similar enough, within all members of a species, to allow brain size to account for any substantial part of an iq score is obviously wrong.
Quote me saying that.
 
The notion that brain size/body size ratio is correlated to intelligence on a phylogenetic level is not disputed. You learn that in high school biology class.
If this is such common knowledge and one learns it in high school, why did you resist the very idea so much in the other thread?

Did you realize this is an argument you can't win (because all evidence supports my thesis), and so you're now changing your mind, pretending that this is the stance you had from the beginning? So now you're all like, "Yeah, brain size matters, Duh!" Well it's better than remaining in the intellectual gutter. Congrats.

That's right. You failed to make a proper question.

See discussion here:

http://sciforums.com/showthread.php?t=57867

It's all been said already.

How do you define a proper question? And how was my question not proper?

Just because something has been debated in one place, and a similar question was asked somewhere else does not make it not proper.
 
If this is such common knowledge and one learns it in high school, why did you resist the very idea so much in the other thread?

Because you are a racist.

I explained it to you many times and each time you fall back on your racist views.

Once again you assume I agree with you. You fail once again the real IQ test.

There is no correlation to my statement in this thread and the idea that
1. races exist.
2. races have different intelligence levels.
3. the human brain relies on brain size for intelligence.

Needless to say you avoided all data in the other thread that went against your racist ideas. Also you avoided the important questions.

You still haven't answered the question: what is the difference between a rodent brain and a human brain?

For instance:
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.
 
Spurious... first off, I am not a racist. Second, this thread has nothing to do with racism or your hatred for people who notice things that threaten your PC ideals.

No matter what you'd like it to be, this is a thread that demands people to realize that brain size matters.

what is the difference between a rodent brain and a human brain?
Lots of things, I presume. What's the point?
 
No matter what you'd like it to be, this is a thread that demands people to realize that brain size matters.
It is not unimportant. That is not the same as saying it is important. As has been pointed out previously the organisation of the brain is much more important than its size.
Now I know you are saying you wish to arrive at some consensus on just what the effects may be, but it seems you may already have some ideas in this direction. Could you share those with us now?
 
I used to wonder during exams why the big head kids always scored higher marks than the pin heads in school!!
 
It is not unimportant. That is not the same as saying it is important. As has been pointed out previously the organisation of the brain is much more important than its size.
Now I know you are saying you wish to arrive at some consensus on just what the effects may be, but it seems you may already have some ideas in this direction. Could you share those with us now?

The only purpose is to demonstrate that brain size and body ratio does indeed correlate with intelligence as measured by IQ. The effects of these intelligence differences are for another discussion.

I just wanted to clear it up, because many people, and not stupid people, mind you, have said in other threads "there is no correlation of brain size and intelligence," and "brain size has nothing to do with intelligence!"

I found it amazing, the sheer number of people who are ignorant about the importance of brain size. So I made a thread that deals with it and confronts the ignorance.
 
The only purpose is to demonstrate that brain size and body ratio does indeed correlate with intelligence as measured by IQ.
you evaded this point the first time, let's see if you evade it again.
brain size can be coorelated to muscle mass.
do bigger muscles mean a better athlete? explain your answer.
 
Depends on the athlete. Distance runners tend to have little muscles, especially when compared to sprinters.

Speaking of which! I'm out for a run. Toodles!
 
surface areas of various brains.
yes indeed, size matters.

Total surface area of the cerebral cortex (human) = 2,500 cm2
Total surface area of the cerebral cortex (lesser shrew) = 0.8 cm2
Total surface area of the cerebral cortex (rat) = 6 cm2
Total surface area of the cerebral cortex (cat) = 83 cm2
Total surface area of the cerebral cortex (African elephant) = 6,300 cm2
Total surface area of the cerebral cortex (Bottlenosed dolphin) = 3,745 cm2
Total surface area of the cerebral cortex (pilot whale) = 5,800 cm2
Total surface area of the cerebral cortex (false killer whale) = 7,400 cm2
http://faculty.washington.edu/chudler/compare2.html

you will notice humans aren't even in the top 50%.
 
Depends on the athlete. Distance runners tend to have little muscles, especially when compared to sprinters.

Speaking of which! I'm out for a run. Toodles!
in your opinion what makes a better athlete, big muscles or training?
can a person without big muscles be trained to perform as good as a person with big muscles in say mountain climbing?

i would venture that a trained boxer can whip an untrained musclebound brute.
 
in your opinion what makes a better athlete, big muscles or training?
Training.
can a person without big muscles be trained to perform as good as a person with big muscles in say mountain climbing?
It depends. Is the other mountain climber with the big muscles well-trained? How big are his muscles? Sometimes huge muscles can get in the way. But it's hard to say. I don't know much about mountain climbing.

i would venture that a trained boxer can whip an untrained musclebound brute.
Me too. But isn't that common sense? Does it really say anything at all? Furthermore, does it have anything to do with the topic at hand? I was walking through with your example, hoping you'd have a pertinent insight... if you do, please, by all means, share!
 
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