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    My, my! What a big brain!
    By James Moon | March 30th 2010 12:04 PM | 9 comments | Print | E-mail | Track Comments
    About James

    I am a licensed clinical psychologist in Virginia and Florida. I have been practicing since 1982. I treat a wide variety of disorders. I also write...

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    A very interesting question has been posed by colleague Mark Changizi (see his fascinating blogs at www.science20.com) related to brain size as it relates to body size. He presents good information that shows the rather constant relationship of brain size to body size. He asks the question, essentially, if bigger brains do not make for more intelligent animals, why are there bigger brains?

    One particularly intriguing statement refers to the fact that neuronal tissue is a rather expensive form of tissue, so if the neuronal tissue is not really needed, why is it there? This is a good question, and perhaps the most parsimonious answer is that the neuronal tissue may be needed after all. For example, if we were to remove neuronal tissue from a cow, would the cow be affected? The most precise answer would involve determining exactly how much tissue was removed as well as the particular location(s) of the removal. However, in general, it would probably be the case that if we removed a non-insignificant amount (whatever that might be) of neuronal tissue from Ms. Bessie, Ms. Bessie would experience some non-insignificant change. This suggests to me that all of Ms. Bessie’s neuronal tissue (more-or-less) is needed. To argue further, we could then attempt to remove a proportionately similar amount of neuronal tissue from a rat. In so doing, would the essence of Mr. Rat change proportionately? Again, the most precise answer would involve determining exactly the right proportion as well as the functionally similar location(s) of the removal of neuronal tissue. Nonetheless I think it is plausible that if one were to take a non-significant amount of neuronal tissue from Mr. Rat, Mr. Rat would experience some non-insignificant change, much in the way we reasoned about the demise of poor Ms. Bessie.

    Another particularly intriguing statement made by Mark (and I have seen similar statements made by others) refers to the assertion that a rat is roughly equivalent in intelligence to a cow. I wonder about that. Cows can do things that rats cannot (besides jumping over the Moon). Does that make a cow smarter or dumber? Or is it that we just do not have very good definitions of intelligence even for humans, let alone non-humans? In fact, I would argue that the best we can hope for is to compare humans against humans (or ducks against ducks, etc.) when it comes to intelligence, and as Francis Galton and other students of intelligence (yours truly included) have found, it is not as simple or straightforward a process as it looks. When one tries to determine the intelligence of another species…well, good luck. If one tries to compare the intelligence between species, one is engaged in a very speculative process indeed. To be more species-centric I will assert that I am a reasonably bright human being, at least in my culture at this particular period in time. (However, if you use any kind of language-based assessment tools, they must be in English—I do not want to look bad.) I will also confess freely that am a profoundly lousy and quite dumb duck. Even with my larger human brain, I really do not excel at duck things. However, the mallards outside of my door seem to fairly adept at swimming in the swift river current despite the cold temperature of the water.

    My point is that, at least with mammals, the size of the brain is limited to the size of mom’s birth canal (more-or-less), and the brain tissue involved is probably the more-or-less minimum amount needed to be a reasonably good [insert your favorite mammal here]. I would find it really challenging to stand in a field and chew food all day long, but my bovine brethren seem to have no problem with this. Then again, they cannot type this blog. Who is smarter? I give up.




    Comments

    Gerhard Adam
    Unfortunately, we simply have no idea what intelligence actually is in any meaningful way.  As humans we tend to view it in academic terms, which I suppose is no coincidence since that is what IQ tests were originally intended to assess.  However, it should be equally clear that such a definition is far too narrow in scope and doesn't actually provide much insight into what is meant by intelligence.

    In addition, it should be clear that whatever we're measuring with IQ isn't intelligence, since it seems to be far too variable.  If one considers the Flynn effect of changing IQ's over generations, it becomes clear that this isn't an evolutionary effect, so whatever is being measured isn't subject to natural selection and consequently can't be considered part of whatever innate intelligence evolved in humans.  In humans I would be much more inclined to consider a cultural "intelligence" whereby it is a collective knowledge that shapes our "intelligence" (as you indicated in referencing your culture). 

    It has always struck me as unusual that humans talk about human achievements despite the fact that no one possesses the intelligence or knowledge to actually know how it all works. Modern society could not be replicated by a single individual or even a small group.  So, once again, it seems clear that whatever we mean by human intelligence, it isn't applicable to individuals in the same way as it is to large social groups.
    Mundus vult decipi
    crazymodem
    Gerhard, there is a saying that IQ is what intelligence tests measure and intelligence tests measure IQ. I think some do not see this as a cynical statement of fact. I also appreciate the distinction you imply between an individualistic worldview and a collectivistic worldview. We too often forget that in North America, an individualistic worldview is considered to be so "normal" that we tend to forget that other cultural groupings of humans interact with the world in an entirely different manner. It takes a different kind of intelligence (whatever that is) to do well in an individualistic culture as opposed to a collectivistic culture.
    You also mention the Flynn Effect, which addresses the overall rise observed in IQ scores over time. As you imply, one cannot infer that as IQ scores increase generally, intelligence increases generally. I think even the more cogent ideas put forth to explain the Flynn Effect seem to miss the point that we still do not quite know what intelligence tests are really measuring. So trying to account for the Flynn Effect seems to be rather pointless. If we substitute the word "intelligence" with a nonsense word such as "bloog," maybe we can see why trying to explain the Flynn Effect does not make much sense. We can assert, "a BQ is what bloog tests measure and bloog tests measure BQ. The Flynn Effect has noticed an overall rise in bloog over the course of several generations." Well, ok, I feel smarter now. Thank goodness we are studying the Flynn Effect. (The Flynn Effect, in effect, is studying a tautology.)

    One final point about IQ tests. IQ tests were originally developed to sort out and categorize human beings at the far lower end of the cognitive ability spectrum. Although Francis Galton first proposed the idea of IQ-type testing to sort the elite from those of lesser culture (because he did not want those of lesser culture to breed--and yes, Galton coined the term "eugenics'), it was not until Binet (and Simon) began to develop an age-based testing scheme that the IQ test as we know it today began to take shape. The Binet test allowed the French to categorize children into more-or-less homogenous groupings to help the French educational system comply with their (then) new law that mandated schooling for all children, with the focus being upon categorizing those children at the lowest end of the cognitive spectrum. Back in those days, the proper terms for low cognitive abilities were idiot, imbecile, and moron (moron was a term coined by an American psychologist--it means dull). Of course we have progressed to the point where we are much kinder in our terminology. Now we commonly use the word retarded (or the more sanitized cognitively-impaired) modified by words such as mild, moderate, severe, or profound. But the damage done to these human beings and their families is still the same. We are attempting to classify fellow human beings using concepts of dubious utility and validity. In so doing, we can lose sight of the fact that our fellow human beings, so-classified, are some of the best electronics assembly line workers in the business. I suppose you can tell I am not a big fan of IQ testing, huh?
    Gerhard Adam
    With good reason ....

    My interest lies in the fact that once we remove human achievement (as an overall cultural phenomenon), then what do we actually have left to describe human intellect?  The specific point is that it changes the entire question with respect to animal intelligence, since that is so often compared on the basis of such human achievements and most animal's lack thereof.

    In addition, I'm quite put off by some of the transhumanist agenda which proposes using computer technology to advance human "intelligence" without even knowing what that means.  In particular, the obvious question is on what basis do we assume that more of "it" is desirable?

    I'm also interested in assessing the intelligence of aboriginal people since it is clear that they are the evolutionary products of human intellectual evolution as much as anyone else, then there is an obvious line of demarcation between the developments of "western civilization" versus those of tribal societies.  I'm not inclined to think these differences are intellectual as much as they are a product of how the various social groups are organized and how they can bring specialized skills to bear on problems.  In other words, modern society with it's supposed "intellectual" achievements is a product of increased individual specialization rather than overall human intellectual development.  So, needless to say, I find this entire topic intriguing.
    Mundus vult decipi
    logicman
    I still think we should be looking at unintelligence.  Unintelligence gets you killed, so you are extracted from the gene pool.  Instead of looking at specific instances of what looks like intelligent behaviour, look at the generalities: what are other members of a species doing on the whole that the dead one didn't do?

    What do most mammals do in a thunderstorm?  What do humans do?  Which has greater survival value?

    For a very primitive life-form in a nutrient pool, moving out of the pool might be unintelligent.  At that level, intelligence is just staying where the food is - or rather, moving either along a food gradient or across it in the direction of increasing food.  The problem there is that if all zoom in on a small pocket of richness they may all die.  However, an element of randomness may lead to some creatures crossing a low to reach a more bounteous high.

    I deduce that intelligence without at least some element of unpredictability of outcome is ultimately fatal to a species.  It follows that if IQ tests show a slavish adherence to communaly shared paradigms then IQ tests are testing unintelligence.  Which is why I like to tell people that my IQ is minus 120.
    crazymodem
    Patrick, without being too crass about the matter, the originators of IQ testing were doing as you suggest, i.e. focusing on those with minimal cognitive prowess. Some suggested that the tests should be called stupidity tests instead of intelligence tests. As noted earlier, Galton coined the term eugenics. He wanted to give financial subsidies to those humans he believed should breed. He wanted to give charity to those he determined should not breed (so long as they did not breed--otherwise he wanted to show them no mercy). He actually had some fairly prominent followers regarding his ideas of eugenics. Even one of my favorite authors, Isaac Asimov, once wrote (in one of his many scientific articles) that people should be allocated votes based on IQ. Dr. Asimov was a brilliant writer on many non-fiction academic topics in addition to being one of the premier science fiction writers. When he put forth his ideas about IQ and voting, I knew this would be a difficult subject for others to grasp. We have reified the construct of intelligence to a very high level.
    logicman
    James: I'm aware of the eugenics aspect.  If I remember rightly the idea of linking intelligence and eugenics has its roots in phrenology and suchlike pseudoscience.

    Isaac Asimov is also one of my favorite authors.  However, he is also one of about seven people  who wrote for public consumption in the 1970s that we were in for some global cooling.  The science at the time was in fact not settled, but leaning strongly towards global warming.

    Dr. Asimov was a brilliant writer on many non-fiction academic topics in addition to being one of the premier science fiction writers.
    That's how I like to remember him. :-)
    crazymodem
    Patrick, the phrenologists went from town to town reading the skulls of customers and pronouncing them with all sorts of abilities and limitations. I suppose it was prudent to leave town before any of their predictions failed to come true. The modern day equivalent was seen when graphologists used to set up old mainframe computers in shopping malls and trade printed Barnum statements for dollar bills.
    logicman
    James: IQ testing and phrenology are just two aspects of anthropometry.  There is scientific dispute over whether or not we can 'profile' people, yet many police forces claim to be able to do just that.  I wonder how many innocents are languishing in prison because of the appiance of bad science.

    Some great resources in this area:
    http://www.crimetheory.com/Reading/further.htm
    Mark Changizi
    Hi James,

    Thanks for the comments at my piece! I agree that all our brain is used and needed, and also agree there's a lot of worry about measuring how intelligent other animals are, and that we have to be wary of anthropomorphizing. But when does try to estimate it, it does correlate well with relative brain size, suggesting we're on to something.  On the birth canal, my guess has always been that that is highly exaggerated.  If even greater head size were selected for sufficiently strongly, then females would be selected for wider pelvises, and potentially for gait modulations dealing effectively with the new morphology. 

    - Mark