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What is intelligence?

  1. Jun 4, 2009 #1
    I have two points I'm thinking about here...

    1. What is intelligence? .. If a person is said to be more intelligent than another, does he have more gray matter? Are neurons organized in a different arrangement allowing for more efficient thinking; a more efficient pattern of application of those neurons?

    2. What makes a great physicist? How can one or two individuals think so much more clearly over the unknown than hundreds of others?
  2. jcsd
  3. Jun 4, 2009 #2
    Abstract problem solving ability.
    Money and a good publicist?
  4. Jun 5, 2009 #3
    IMO, intelligence is a generalized "rating" of the 'quality' of many aspects of one's thought process, in different applications.

    In general, one can be more "intelligent" with more experience, better memory of said experience, a well developed sense of associativity (IE both realistic and high-volume), and (probably) curiosity/motivation.

    I expect that the reason for "intelligence" is both biological as well as experiential. Children who are encouraged to explore (as opposed to "sit down, shut up, and listen") generally perform better on intelligence tests, as I recall being evidenced in an inner-city education program starting with babies and toddlers. Also, I know that tests on neural pathway development is highly affected by inputs like video games and television, although how that relates to "intelligence" is unclear.

    However, I expect that many aspects of intelligence are also biological, such as the ability to reference one's own memory, which I expect would likely be unaffected by experience (that's just a guess, though). There's apparently debate about whether or not brain size and brain "layout" encourage things like language and "higher" thought. See the debate with a chimpanzee who was attempted to be raised as a human:

    Ultimately, though, intellect is still a very fuzzy term, since the only means of measuring it come from grading performance on tasks, which can be aided by things like experience or other knowledge. If my job was to design paper models, and you gave me a standard IQ question where an object is "rolled out flat", I'd be more likely to perform well on the question, regardless of whether or not I had seen it before, thanks to my similar experiences.

    As far as physics goes, I suspect some people's experiences and particular talents lend themselves phenomenally well to physics. I recall an interview on This American Life on NPR with someone who was exceptionally BAD at physics, but reasonably smart when it came to things like engineering and mechanics. From the sounds of it, he was good at thinking of things in more-or-less a Cartesian method, which made things like relativistic physics (and certainly quantum physics!) incomprehensible.

  5. Jun 5, 2009 #4
    Intelligent people have a greater number of connections between their trillions neurons.
  6. Jun 5, 2009 #5
    Is that a fact? if so , would you please provide a reference? Moreover, I would be delighted if someone pointed out a reference to whether brain 'size' of humans (not to be compared with other animals, since it is already known that the ratio between body size and brain size seems to be the deciding factor for intellectual capability, and in this context, we -humans- excel) compared to other humans. That is, did Einsteind, Bohr, Newton have 'bigger' brains than most people?
  7. Jun 5, 2009 #6
    Huh-- now that I was unaware of-- Does that mean I'm smarter because I'm skinny? :)

  8. Jun 5, 2009 #7

    Fact? Hmm, i'd say it's a theory but it's very likely to become a fact. I've seen this in various articles on neurobiology:


    http://expertvoices.nsdl.org/cornell-info204/2008/04/14/1278/ [Broken]


    "Mental Activity

    • Education and intelligence. Many epidemiologic studies have associated higher levels of education and intelligence with lower rates of dementia, a general loss of intellectual function and not just memory. This relationship has been explained by brain-reserve capacity, loosely defined as the number of connections between neurons. The theory — and it is just a theory — is that the neurons of the intelligent and educated brain have more connections than a less intelligent, less educated brain. The dementia rates may reflect the fact that people with a larger brain-reserve capacity can perhaps afford to lose more neuronal connections before the loss shows up as a noticeable brain deficit like dementia."

    http://library.pchrd.dost.gov.ph/index.php/news-archive/831 [Broken]
    Last edited by a moderator: May 4, 2017
  9. Jun 5, 2009 #8
    It has to do with the overall size of your body and the corresponding brain size. For example, the blue whale has the biggest brain than any living creature. However, it is not any smarter than a rat. http://www.youramazingbrain.org/Insidebrain/brainevolution.htm" [Broken]
    Last edited by a moderator: May 4, 2017
  10. Jun 5, 2009 #9


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    JoeDawg hit it on the head. Intelligence is a measure of abstract problem-solving ability.
  11. Jun 5, 2009 #10
    No way. The man who dies with the most toys wins the inteliganse game! This should put me somewhere in the vicinity of moron.
    Last edited: Jun 6, 2009
  12. Jun 6, 2009 #11
    I think this is definition is vague and not clear enough to help our understanding of intelligence. There is no 'standard' definition for intelligence but there are plausible suggestions.
  13. Jun 6, 2009 #12
    There is also a matter of regulating bodily functions. Octopi and squid have fairly large brains for their body mass but the majority of the processing power goes into their capacity to independantly control and articulate eight sperate limbs.
    Last edited by a moderator: May 4, 2017
  14. Jun 6, 2009 #13
    Good point. But are you refering to the complexity of the bodily functions or its scale?
  15. Jun 6, 2009 #14
    I believe it would be somewhat both. The addition of each limb adds both to the scale and complexity of the task. I am not aware of specifics or research. I just have a friend who is a cognitive science major with a squid fetish. ;-)
  16. Jun 6, 2009 #15
    Isn't Penrose now working on similar problems, that is intelligence, creativity and consciousness ? AFAIK he is trying to understand how those emerge from neuron network.
  17. Jun 6, 2009 #16

    "I have a bigger processor than you, therefore I am more intelligent"
  18. Jun 6, 2009 #17
    In an old book there were presentations of brain sizes of famous scientists (such things may scare us from being famous...). As I remember, Newton had slightly above average size, Leibnitz far below average and Gauss almost double average size. Einstein is today reputed having had just 85 % of average size. (If that is true?)

    Somewhere I also read, that a small mouse or aquainted had the biggest brain compared to body. So human has not biggest brain either relatively or absolutely.

    At least regarding IQ-tests, they maintain having found a positive but weak correlation between brain size and IQ. But just statistically with many exceptions. Personally I think, that if IQ increased with brain size it should be more of an "exponential" dependance than attenuating dependance, as it appears to be.

    Around 1930 there was a "symposium" regarding IQ related to brain size. The discussion was
    untidy and the conference broken up when a participant said: "I have noticed that most of you maintaining brain size doesn't matter have small heads!" :uhh:
  19. Jun 7, 2009 #18
    http://www.youramazingbrain.org/Insidebrain/brainevolution.htm" [Broken]

    This might be hoax(and I feel it is) but if so, I would like to see something contradictory.
    Maybe considering the brain size is overly simplistic. My hypothesis was that 'bigger' brain = more processing power, greater memory and higher cognitive abilities. However, an important factor that could have been overlooked is how well those individuals that we are measuring their performance against their brain size are they trained to efficiently use and recognize their mental abilities? Some might have more processing power than others but having an unorganized mind might impair their performance in an IQ test for example.

    I still feel that my words are abstract and not on solid foundations. If there is someone who has a higher knowledge on the subject, please identify yourself and elaborate.
    Last edited by a moderator: May 4, 2017
  20. Jun 8, 2009 #19
    Did you mean this showed rats in fact have brains at about human percentual size or did you mean it showed they not actually reach human % size? I may have expressed it fuzzy, but meant a certain species of mouse (or related) they had found. Its % brain was perhaps double up humans or more, but I don't remember exactly. Perhaps 5 times human brain %.

    I agree with your reasoning about brain capacity, but the number of active processing
    cells and how they are organized may not be judged from external size of brain. And small animals, not the least insects, of course must have an extremely higher density of "neurons" in their brains than bigger animals.

    I guess IQ-tests show a very primitive aspect of intelligence. They appear regard intelligence as a matter of just "recognizing patterns". I don't think higher levels
    of thinking has much to do with that.
    Last edited by a moderator: May 4, 2017
  21. Jun 8, 2009 #20
    Could you please find a link to that? -not that I am doubting you but I want to see for myself-

    Again, I would really like to see something that says that insects have greater density of neurons than bigger animals. I mean, which is better, if the more density is better, then why don't the lions for example have that kind of density? or even humans? we are certainly higher thinkers than ants.

    People can be trained in order to do that, does that mean they became more intelligent or just merely have more developed skill? I think this depends on one's definition of intelligence.
  22. Jun 8, 2009 #21
    Regarding the certain species of "mouse", having very large brain/body %, I cannot for the moment tell where to read about it. But I have seen it mentioned several times. But as you can see here
    http://nationalzoo.si.edu/Animals/ThinkTank/TheBrain/default.cfm [Broken] already
    squirrels are known having bigger brain % than man. So it is not astonishing a mouse can have still bigger brain %.

    Regarding insects, I have seen different opinions about density of nerve cells in their brains.
    Some reason their nerve cell diameters are 1/30 or 1/50 compared to bigger mammals, giving
    27000 or 125000 times the density in mammal brains. An insect nerve cell also has several more tasks than a mammal nerve cell (some mention 6 times as many tasks) giving further
    multiplication. Insects also have much of their nerve system distributed in body. So an insect brain system may (at least theoretically) reach human brain potential. But most enthomologists appear content saying a bumblebee has at least the brain capacity of
    a mouse.

    Regarding your question why bigger mammals don't use a higher neuron density like insects,
    it may depend on the size of their basic building elements. The body comes from a "factory" using a certain standard of building elements. And if for instance their brains at some stage began using insectoid nerve cells, it had developed to an other kind of animal. Perhaps
    an animal cannot survive having too complex brain - at least not as an animal.
    Last edited by a moderator: May 4, 2017
  23. Jun 8, 2009 #22


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    Not picking on you specifically Grandin but, how does any of this help answer the OP's question?

    Undoubtedly there's a relationship between brain-body ratio and intelligence, but it isn't defined by it. The OP asked how we define it. Could we get back on that topic?
  24. Jun 8, 2009 #23
    I believe this was a quest to try and understand where does intelligence originates and what is it related to, which can of course improve our definition of intelligence and hence provide a better answer to what intelligence is.
  25. Jun 8, 2009 #24
    Thanks for well-meant advice, DaveC ! Maybe this is more focusing on OP topic:

    At an employment interview, the manager told me there are two main kinds of intelligences:

    1) From inside and out (i.e from given rules and presumptions reach a certain goal. For instance construct something by using given tools and known engineering facts).

    2) From outside and in (i.e from known circumstances conclude what rules and presumptions
    lie behind these circumstances).

    Of course most intellectual tasks are a mix of these, for instance a chessplayer has to
    both plan himself and conclude what his opponent is planning. Although computer chess programs don't "reason" that way.
    Last edited: Jun 9, 2009
  26. Jun 8, 2009 #25
    I don't know...personally I respect people with higher IQ's as "intellectual quotients" than "intelligence quotients." Truth is, even the developers of the first intelligence tests didn't know exactly what they were measuring. There are different kinds of intelligence, sure. There are very intelligent physicists and mathematicians, but then again, there are also very intelligent orators, writers, musicians--people who can speak 5 languages...what kind of intelligence is this? I'm not talking about the left vs. right brain issue, rather, the different brain areas that are activated when preforming different tasks. For example, in one MIT study, it was found that different brain areas react to even different kinds of math problems; in subjects "asked to compute two numbers to reach an exact answer, the brain was active in the left lateral frontal lobe, an area that has been intimately tied to spoken language" (Talan) On the other hand, subjects "asked to approximate answers -- is 97 plus 57 closer to 100 or 200, or what number is between 5 and 7, for instance -- the parietal lobes, located deeper in the brain, were most active. This brain area is used in spatial tasks" (Talan). Needless to say, different people are endowed with smaller or larger brain areas depending on the individual biological discrepancies. for example, one's "Broca's area", a region used in speech, is often located in slightly different positions and can vary in size between the person. No to people are alike.

    This leads us to a simple truth--some people are more well rounded than others. some people are math and physics geniuses, but they can't write a term paper for the life of them, let alone give a speech or lead a group project. then we have those who are great communicators and linguists, but are not logical at all. We also have people in between, on the outisde--all over the place. To want to be successful, one does not necessarily need just brains, but a mind. And to be successful, one needs not only brains and a mind, but guts.
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