Does brain size matter?

Discussion in 'Biology & Genetics' started by francois, Oct 14, 2006.

  1. valich Registered Senior Member

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    3,501
    Still, irrelevant of brain size, what are you measuring?

    All an IQ test measures is how well you do on an IQ test. It's extremely debateable that an IQ test measures how intelligent, creative and smart you are, as well as how good and how large your memory capacity is. So we're still back in square one: "Does brain size matter?"
     
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  3. francois Schwat? Registered Senior Member

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    Unfortunately, that's not scientists who study intelligence believe. I've been over this many times before with other people. Though there is not yet a comprehensive theory of intelligence, we have reasons to believe IQ tests measure something valuable. It is the single best indicator of a person's ability to perform at a job, his health, level of education, the IQ of his spouse--many other things as well. Please know at least something about what you are talking about before you start saying things.

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

    IQ is not meaningless. Learn something. It's remarkable how many people think as you do. Please. Just read the wiki link. Take about 15 minutes reading it. It might change your mind about a few things.
     
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  5. Oniw17 ascetic, sage, diogenes, bum? Valued Senior Member

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    Regardless of whether brain size affect intelligence or not, environment, and what you learn in it affect intelligence a lot more, right?
     
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  7. francois Schwat? Registered Senior Member

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    Well, environment certainly can affect intelligence more than genetics. For example, if you suffered severe malnutrition during your formative years or if you got slammed in the head with a bat, those would have adverse effects on your cognitive ability most likely. Those are examples of environment having an adverse effect on intelligence.

    Generally, however, these things don't happen very much. Overall, genetics seem to be more important in determining an individual's intelligence. That's what I get from the studies I've read anyway. But that's really out of the scope of this thread. Good point though. However, it's already been talked earlier in the thread. Perhaps you could read thread more thoroughly before you make a contribution?
     
  8. valich Registered Senior Member

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    My IQ was measured to be 140 a few years ago. I consider myself dumb. In school, many younger students far surpass me in memory and do much better than I on the tests. I don't think that I am very creative. Nor am I able to hold a steady job because I yearn for diversity and another way of life.

    These socalled "scientists" that you talk of, are they not psychologists? A psychologist is not a scientist. I have a minor in my undergrad in psychology and from my own experience a lot of psychologists study psychology to better understand there own problems that they have in understanding themselves and society, and many times to try to understand their own psychological problems.

    You tell me to "Learn something," yet you have no idea what I already know. And what I can teach you! Who the hell do you think that YOU are to tell ME to "Learn something"? Peewee francois? You can call me the same, but I won't be offended.
     
  9. francois Schwat? Registered Senior Member

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    How well you personally do on IQ tests and how dumb you consider yourself is irrelevant.
    Yes, the scientists I'm talking about are indeed scientists. The scientists who study intelligence find that IQ is an indicator of something valuable--general intelligence.

    Well, you're right. I don't know what you know. But you already made apparent what you don't know with this statement: "All an IQ test measures is how well you do on an IQ test." If IQ only indicates how well a person does on IQ tests, why do larger brained people score better than smaller brained people? What could be the reason for this?

    Did you in fact read the wiki link? Did you learn anything? Did you change your mind? If you didn't read it, please, for the love of Buddha, educate yourself. Take 15 minutes out of your life to learn something.

    Once again, we're getting off topic. If you want to discuss the value of IQ, why don't you start a new thread?
     
  10. QFT2 Registered Member

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    3
    Though IQ is important, one must realize that IQ is not a panacea, it is a good indicator of job performance, BUT it is not a good indicator of team performance.

    What good is it to have high-IQ people around if the system is faulty, just look at Germany in WW2, plenty of intelligent people yet they committed some of the worst atrocities known to mankind. Look at the former Soviet Union, plenty of intelligent people yet they oppressed their own people, killed dissidents, and committed many atrocities. Look at Maoist China, full of intelligent people yet he oppressed his own people, killed dissidents and committed many atrocities.

    One might say that intelligent people were not allowed to occupy positions that would affect the system; the problem is that one would have to prove that the people in positions of power were not intelligent. We can offer one counterexample, Nazi Germany. The Nazis in typical German fashion chose the appropriate people for the job, the only problem is that their ideology was warped so intelligent people thought it was natural to hate and exterminate Jews.

    The system is greater than its parts, having intelligent people in the right positions does not guarantee a good system. You need a good system to start and then fill in with qualified people. IQ tells you nothing of work habits, someone can be highly intelligent but lazy, personal habits, someone can be highly intelligent but cannot socialize with important people. In addition, IQ tells you nothing of ethical habits, someone may be highly intelligent but crooked. People might say well high IQ people have a lower crime rate, well here is the problem, an intelligent bad guy can easily outsmart police and investigators hence you will rarely see a high IQ person, who committed a crime, being caught by police.
     
  11. madanthonywayne Morning in America Registered Senior Member

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    Sounds to me like you didn't do so well on the IQ test.

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    In college I volunteered to take part in a psychology experiment for extra credit. It was supposed to test the relationship between how well you score on a test and your perception of how accurate the test was. So they gave me some bogus test, gave me a good score, then asked how I rated the test.

    What they were actually testing was immediately obvious to me [after all, I have a very big head

    Please Register or Log in to view the hidden image!

    ], so I rated the test as poorly as possible. Then the tester says,"Well, I must admit that we were not testing what we originally told you...." I said, "I know, you were testing the relationship between test performance and one's assessment of a tests accuracy." He gave me a funny look, and complained that now he'd have to throw out my data. I still got the extra credit, though. I never did hear how the test came out.
     
  12. francois Schwat? Registered Senior Member

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    Thanks for your response, but it doesn't really have anything to do with the thread. Maybe you could start another thread that discusses whether or not intelligent people are good for the world.
     
  13. leopold Valued Senior Member

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    brain size, in and of itself, is not a reliable indicator of intelligence.

    edit
    francois you have so far failed to produce the studies themselves. all you have provided is conclusions based on those studies.
     
  14. francois Schwat? Registered Senior Member

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    The studies themselves are actually really difficult to find on the net. You have to subscribe to medical and science journals to get them. But I have found several abstracts that indicate what the studies have found, which all agree that brain size does correlate with intelligence. If the studies themselves found no correlation between brain size and intelligence, I have difficulty believing the written abstracts would indicate something entirely different. Wouldn't you find something like that very peculiar? Don't you think doing something like that would be considered a bad career move?

    Furthermore, in many of the news articles I've provided have quoted the researchers directly. If Witelson found no correlation between brain size and intelligence, wouldn't it be an odd thing for her to say, "What is very clear is that there is a correlation between brain size and intelligence, particularly verbal ability."? Isn't that weird?

    Furthermore, I've found no evidence whatsoever or any studies that show the opposite of my argument, to wit, your argument, leopold99--that brain size has no correlation with intelligence. The consensus in the scientific community is that brain size matters.

    You have shown me nothing whatsoever that shows that smarter people do not have larger brains.
     
  15. leopold Valued Senior Member

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    and i can conclude based on studies that churches are the cause of murder.

    until you produce the studies themselves all you have provided is someones opinion.
     
  16. valich Registered Senior Member

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    3,501
    No one has yet to post any credible studies to support this statement. Refer to James' reply about measuring brain capacity.
     
  17. valich Registered Senior Member

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    3,501
    From what you are telling us here, you were involved in a psychologocial test that was trying to determine the accuracy of the test: not in what the test determines. This implies, as I stated, that there are questions as to whether or not an IQ test measures intelligence, or what, if anything, it does measure.

    Thanks for supporting my view.
     
  18. valich Registered Senior Member

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    3,501
    Yes. As Leopald99 stated above, you are making reference to "abstracts" of studies but not even providing us with any references to these studies for us to further examine. Please post what you are finding in these abstracts, and then of course you must provide the source (article title, journal name, authors, issue, date and pages) or a weblink so that we can also review the literature. Thanks.
     
  19. francois Schwat? Registered Senior Member

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    http://lib.stat.cmu.edu/DASL/Stories/BrainSizeandIntelligence.html

    Abstract:
    Are the size and weight of your brain indicators of your mental capacity? In this study by Willerman et al. (1991) the researchers use Magnetic Resonance Imaging (MRI) to determine the brain size of the subjects. The researchers take into account gender and body size to draw conclusions about the connection between brain size and intelligence.

    Willerman et al. (1991) conducted their study at a large southwestern university. They selected a sample of 40 right-handed Anglo introductory psychology students who had indicated no history of alcoholism, unconsciousness, brain damage, epilepsy, or heart disease. These subjects were drawn from a larger pool of introductory psychology students with total Scholastic Aptitude Test Scores higher than 1350 or lower than 940 who had agreed to satisfy a course requirement by allowing the administration of four subtests (Vocabulary, Similarities, Block Design, and Picture Completion) of the Wechsler (1981) Adult Intelligence Scale-Revised. With prior approval of the University's research review board, students selected for MRI were required to obtain prorated full-scale IQs of greater than 130 or less than 103, and were equally divided by sex and IQ classification.

    The MRI Scans were performed at the same facility for all 40 subjects. The scans consisted of 18 horizontal MR images. The computer counted all pixels with non-zero gray scale in each of the 18 images and the total count served as an index for brain size.

    A straightforward method for evaluating the relationship between brain size and IQ scores is the correllation coefficient. For the 20 men in the study, the researchers report correlations between IQ scores and brain sizes before and after controlling for body size of r = 0.51 (p-value less than 0.05) and r = 0.65 (p-value less than 0.01) respectively. For the 20 women in the study, the researchers report the corresponding correlations to be r = 0.33 (p-value not significant) and r = 0.35 (p-value not significant). With both genders pooled the correlation between IQ and adjusted brain size was r = 0.51 (p-value less than 0.05).

    Note created Oct 28, 2006
    Brain Size and Intelligence Story - lib.stat.cmu.edu/...


    As an aside... Google notebook kicks ass.
     
  20. francois Schwat? Registered Senior Member

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    EditDelete

    Title: Find More Like ThisStudy Finds Genetic Link Between Intelligence and Size of Some Regions of the Brain.
    Authors: Wade, Nicholas
    Source: New York Times; 11/5/2001, Vol. 151 Issue 51928, pA15, 0p
    Document Type: Article
    Subject Terms: BRAIN
    INTELLECT
    Abstract: Reports on the study that finds genetic link between intelligence and the size of some regions of the brain in humans.
    ISSN: 0362-4331
    Accession Number: 5555402
    Persistent link to this record: http://search.ebscohost.com/login.aspx?direct=true&db=nfh&AN=5555402&site=ehost-live
    Database Newspaper Source
    View Links: Check Article Linker for more options

    Note created Oct 28, 2006
    EBSCOhost - web.ebscohost.com.ezproxy.snhu.edu/...
     
  21. francois Schwat? Registered Senior Member

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    Title: Sex differences in intelligence and brain size: A developmental theory.
    Author(s): Lynn, Richard, U Ulster, Psychology Dept, Coleraine, Northern Ireland
    Source: Intelligence, Vol 27(1), 1999. pp. 1-12.
    Publisher: Netherlands: Elsevier Science
    ISSN: 0160-2896 (Print)
    Digital Object Identifier: 10.1016/S0160-2896(99)00009-4
    Language: English
    Keywords: sex differences; intelligence; IQ; brain size; developmental theory
    Abstract: Presents new evidence on the developmental theory of sex differences in intelligence and discusses alternative attempts to deal with the anomaly by C.D. Ankney (1995), A.R. Jensen (1998), and N.J. Mackintosh (1996). The author discusses a developmental theory of sex differences in intelligence consisting of 5 propositions: (1) the need to begin by defining intelligence; (2) the need to fit data to the model; (3) the adult male advantage of around 4 IQ points obtained by averaging the verbal comprehension, reasoning and spatial abilities is not generally found in the full scale IQ of the Wechsler tests or in the overall IQ of similar tests because the spatial abilities are typically under-represented in these tests; (4) the male advantage of around 4 IQ points among adults can be predicted from the larger average male brain size; and (5) male advantage in both brain size and intelligence is less in children and young adolescents because girls mature more rapidly than boys in general and in brain size in particular. (PsycINFO Database Record (c) 2006 APA, all rights reserved)
    Subjects: *Brain Size; *Human Development; *Human Sex Differences; *Intelligence Quotient; *Theories
    Classification: Cognitive & Perceptual Development (2820)
    Population: Human (10)
    Male (30)
    Female (40)
    Publication Type: Journal, Peer Reviewed Journal; Print
    Format(s) Available: Electronic; Print
    Document Type: Editorial
    Release Date: 20011107
    Accession Number: 2001-03214-001
    Number of Citations in Source: 40
    Persistent link to this record: http://search.ebscohost.com/login.aspx?direct=true&db=psyh&AN=2001-03214-001&site=ehost-live
    Database PsycINFO
     
  22. francois Schwat? Registered Senior Member

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    Title: Brain size and intelligence in man: A correction to Peters.
    Author(s): Lynn, Richard, U Ulster, Coleraine, Northern Ireland
    Source: Canadian Journal of Experimental Psychology, Vol 47(4), Dec 1993. pp. 748-750.
    Publisher: Canada: Canadian Psychological Assn
    ISSN: 1196-1961 (Print)
    Language: English
    Keywords: sex, body weight & size parameters & brain size & IQ, commentary
    Abstract: Comments on M. Peters's (see record 1992-18876-001) claim that there is no association between brain size and IQ. It is argued that this claim is incorrect. Studies showing that there is a statistically significant correlation between brain size and IQ are cited. (French abstract) (PsycINFO Database Record (c) 2006 APA, all rights reserved)
    Subjects: *Body Size; *Body Weight; *Brain Size; *Human Sex Differences; *Intelligence Quotient; Neuroanatomy
    Classification: Neuropsychology & Neurology (2520)
    Population: Human (10)
    Publication Type: Journal, Peer Reviewed Journal
    Document Type: Comment/Reply
    Release Date: 19940701
    Accession Number: 1994-24539-001
    Persistent link to this record: http://search.ebscohost.com/login.aspx?direct=true&db=psyh&AN=1994-24539-001&site=ehost-live
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  23. francois Schwat? Registered Senior Member

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    2,515
    Title: Intelligence and brain size in 100 postmortem brains: Sex, lateralization and age factors.
    Author(s): Witelson, S. F., Department of Psychiatry and Behavioural Neurosciences, Michael G. DeGroote School of Medicine, Hamilton, ON, Canada, witelson@mcmaster.ca
    Beresh, H., Department of Psychiatry and Behavioural eurosciences, Michael G. DeGroote School of Medicine, McMaster University, Hamilton, ON, Canada
    Kigar, D. L., Department of Psychiatry and Behavioural eurosciences, Michael G. DeGroote School of Medicine, McMaster University, Hamilton, ON, Canada
    Address: Witelson, S. F., Department of Psychiatry and Behavioural Neurosciences, Michael G. DeGroote School of Medicine, McMaster University, 1200 Main Street West, Hamilton, ON, Canada, L8N 3Z5, witelson@mcmaster.ca
    Source: Brain: A Journal of Neurology, Vol 129(2), Feb 2006. pp. 386-398.
    Publisher: United Kingdom: Oxford Univ Press
    ISSN: 0006-8950 (Print)
    1460-2156 (Electronic)
    Digital Object Identifier: 10.1093/brain/awh696
    Language: English
    Keywords: human intelligence; brain size; postmortem brains; sex factors; lateralization; age factors; visuospatial ability
    Abstract: The neural basis of variation in human intelligence is not well delineated. Numerous studies relating measures of brain size such as brain weight, head circumference, CT or MRI brain volume to different intelligence test measures, with variously defined samples of subjects have yielded inconsistent findings with correlations from ~0 to 0.6, with most correlations ~0.3 or 0.4. The study of intelligence in relation to postmortem cerebral volume is not available to date. We report the results of such a study on 100 cases (58 women and 42 men) having prospectively obtained Full Scale Wechsler Adult Intelligence Scale scores. Ability correlated with cerebral volume, but the relationship depended on the realm of intelligence studied, as well as the sex and hemispheric functional lateralization of the subject. General verbal ability was positively correlated with cerebral volume and each hemisphere's volume in women and in right-handed men accounting for 36% of the variation in verbal intelligence. There was no evidence of such a relationship in non-right-handed men, indicating that at least for verbal intelligence, functional asymmetry may be a relevant factor in structure-function relationships in men, but not in women. In women, general visuospatial ability was also positively correlated with cerebral volume, but less strongly, accounting for ~10% of the variance. In men, there was a non-significant trend of a negative correlation between visuospatial ability and cerebral volume, suggesting that the neural substrate of visuospatial ability may differ between the sexes. Analyses of additional research subjects used as test cases provided support for our regression models. In men, visuospatial ability and cerebral volume were strongly linked via the factor of chronological age, suggesting that the well-documented decline in visuospatial intelligence with age is related, at least in right-handed men, to the decrease in cerebral volume with age. We found that cerebral volume decreased only minimally with age in women. This leaves unknown the neural substrate underlying the visuospatial decline with age in women. Body height was found to account for 1-4% of the variation in cerebral volume within each sex, leaving the basis of the well-documented sex difference in cerebral volume unaccounted for. With finer testing instruments of specific cognitive abilities and measures of their associated brain regions, it is likely that stronger structure-function relationships will be observed. Our results point to the need for responsibility in the consideration of the possible use of brain images as intelligence tests. (PsycINFO Database Record (c) 2006 APA, all rights reserved)(from the journal abstract)
    Subjects: *Age Differences; *Brain Size; *Intelligence; *Sex Roles; *Visuospatial Ability; Brain; Lateral Dominance
    Classification: Personality Traits & Processes (3120)
    Population: Human (10)
    Male (30)
    Female (40)
    Age Group: Adulthood (18 yrs & older) (300)
    Tests & Measures: Full Scale Intelligence Quotient
    Performance Scaled Score
    Verbal Scaled Score
    Wechsler Adult Intelligence Scale (WAIS)
    Grant Information: This work was supported by grants from US NIH NS62344 and NS18954, and MA-10610 from MRC (Canada), and the Albert Einstein/Irving Zucker Chair in Neuroscience to SFW
    Conference: Society for Neuroscience Annual Meeting, 2002
    Conference Notes: A preliminary report was presented at the aforementioned conference.
    Methodology: Empirical Study; Quantitative Study
    Publication Type: Journal, Peer Reviewed Journal; Electronic
    Format(s) Available: Electronic; Print
    Document Type: Original Journal Article
    Release Date: 20060428
    Accession Number: 2006-01895-009
    Number of Citations in Source: 53
    Persistent link to this record: http://search.ebscohost.com/login.aspx?direct=true&db=psyh&AN=2006-01895-009&site=ehost-live
    Database PsycINFO
     

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