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Re: [evol-psych] Re: Re: IQ tests

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  • O'Dea
    Charles Murray: I don t know anything specifically about this case, but two quick points: (1) the relationship of brain size to IQ has to be adjusted for body
    Message 1 of 10 , Sep 1, 2005
      Charles Murray:

      I don't know anything specifically about this case, but two quick points: (1) the relationship of brain size to IQ has to be adjusted for body size in all cases, whether comparing men and women or Homo sapiens with Homo floresiensis. (2) The relationship is a gradient, not binary. Dr. Gee was refuting a "whole idea" that no one holds (to my knowledge).
       
       
       
      Julian O'Dea: Why must there always be an adjustment for body size?  I have never understood the force of this argument. Larger is larger, isn't it?  That seems to be the argument being put by Prof. Lynn here:
       
       
      “Men have larger brains than women by about 10 per cent and larger brains confer greater brain power, so men must necessarily be on average more intelligent than women.”
       
      No-one comparing male and female muscular strength would think it necessary to "adjust" for body size.
       
      As for the intelligence of Homo floresiensis, as I pointed out at the annual meeting of the Australasian Society for Human Biology last year, parrots and other birds are proving to be surprisingly intelligent despite their small brain size.  Presumably it is a matter of efficient packaging.
       
    • Charles Murray
      You ll have to ask the neuroscientists, but the principle as I understand it is that brain capacity gets taken up just by administrative tasks, as it
      Message 2 of 10 , Sep 1, 2005
        You'll have to ask the neuroscientists, but the principle as I understand it is that brain capacity gets taken up just by administrative tasks, as it were--sending signals to muscles, etc-- so that the larger the body, the larger the brain has to be to maintain the same level of  cognitive abilities. Hence my African Gray parrot can be really smart with a brain the size of an acorn, whereas I seriously doubt that I could. 

        Charles Murray

        On Sep 1, 2005, at 7:48 AM, O'Dea wrote:

        Charles Murray:

        I don't know anything specifically about this case, but two quick points: (1) the relationship of brain size to IQ has to be adjusted for body size in all cases, whether comparing men and women or Homo sapiens with Homo floresiensis. (2) The relationship is a gradient, not binary. Dr. Gee was refuting a "whole idea" that no one holds (to my knowledge).
         
         
         
        Julian O'Dea: Why must there always be an adjustment for body size?  I have never understood the force of this argument. Larger is larger, isn't it?  That seems to be the argument being put by Prof. Lynn here:
         
         
        “Men have larger brains than women by about 10 per cent and larger brains confer greater brain power, so men must necessarily be on average more intelligent than women.”
         
        No-one comparing male and female muscular strength would think it necessary to "adjust" for body size.
         
        As for the intelligence of Homo floresiensis, as I pointed out at the annual meeting of the Australasian Society for Human Biology last year, parrots and other birds are proving to be surprisingly intelligent despite their small brain size.  Presumably it is a matter of efficient packaging.
         


      • Jason Malloy
        ... The distinction has proved meaningful in the evolutionary study of intelligence between absolute brain size and EQ (encephalization quotient) which is a
        Message 3 of 10 , Sep 1, 2005
          > Julian O'Dea: Why must there always be an adjustment for
          >body size? I have never understood the force of this argument.
          >Larger is larger, isn't it?

          The distinction has proved meaningful in the evolutionary study
          of intelligence between absolute brain size and EQ
          (encephalization quotient) which is a measure of brain size over
          and above what is predicted from body size (or what is
          considered needed for basic "house-keeping"). The
          assumptions pan out rather well. Harry Jerison's 'Evolution of the
          Brain and Intelligence' is still a classic:

          http://www.amazon.com/exec/obidos/tg/detail/-/0123852501/

          That's for between-species comparisons. Now within-species,
          or at least within the human species this doesn't appear to be
          the case (but again the IQ/brainsize correlation in humans may
          be spurious). Here are statements from the 'Handbook of
          Human Intelligence':

          "Brain size is not related to body size in humans"

          pg 241 chapter 11. H. Jerison

          "contrary to what is sometimes claimed, no study of brain
          volume (or head size) has shown a substantial decrement in
          correlation after partialling out either height or weight (or both)"

          pg 246 chapter 12. P. Vernon et al

          http://www.amazon.com/exec/obidos/tg/detail/-/0521296870/


          > As for the intelligence of Homo floresiensis, as I pointed out
          >at the annual meeting of the Australasian Society for Human
          >Biology last year, parrots and other birds are proving to be
          >surprisingly intelligent despite their small brain size.
          >Presumably it is a matter of efficient packaging.

          No birds have small bodies, and homo floresiensis has a very
          low EQ. Here's Richard Dawkins:

          "Biologists expect small animals to have small brains anyway
          and they have developed ways of calculating this. The EQ or
          Encephalisation Quotient is a measure of how much bigger (or
          smaller) a brain is than it "ought to be" for its body size, given that
          it is, say, a mammal.

          Calculated in this way, modern humans have an EQ of about 6,
          meaning that our brain is six times as big as it "ought to be" for a
          mammal of our size. Homo erectus is believed to have an EQ of
          about 4, and Australopithecus (our probable ancestors of about
          3m years ago) about 2.5 or 3 (similar to a modern chimpanzee).
          Flores woman comes into the same range as Australopithecus
          or modern chimpanzees. "

          http://www.timesonline.co.uk/article/0,,2092-1336836_1,00.html

          So Flores has tools like an erectus but is encephalized like a
          chimp or Lucy. As for birds, EQ matters, as a big study that just
          came out this year shows:

          "They gathered data on brain mass for 1,967 species.

          In more than 600 introductions of nearly 200 bird species into
          new habitat they found that species with brains large relative to
          their body size tended to survive better in new environments than
          smaller-brained birds.

          Examples include the introduction in the 19th century of the
          European starling to North America.

          "Overall, our results provide strong evidence for the hypothesis
          that enlarged brains function, and hence may have evolved, to
          deal with changes in the environment," they wrote in this week's
          issue of the Proceedings of the National Academy of Sciences.

          The researchers last month published an IQ index guide to birds
          that show corvids — birds from the crow family including ravens
          and jays — are by far the cleverest birds.

          Next on the list are hawks, woodpeckers and herons, while
          partridges, new world quails, emus and ostriches are the dolts
          of the bird world."

          www.hindustantimes.com/news/181_1281672,00040010.htm

          This study is interesting because it added external validity to
          animal intelligence tests (similar in content to human
          intelligence tests) which also showed a connection between bird
          species performance and EQ (same for primates).
        • Ralph L Holloway
          ... Brain size and body size have no signifant correlation from any of the autopsy data I ve seen, so why, within species, would it have to corrected for?
          Message 4 of 10 , Sep 1, 2005
            On Thu, 1 Sep 2005, O'Dea wrote:

            > Charles Murray:
            >
            >
            > I don't know anything specifically about this case, but two quick points: (1) the relationship of brain size to IQ has to be adjusted for body size in all cases, whether comparing men and women or Homo sapiens with Homo floresiensis. (2) The relationship is a gradient, not binary. Dr. Gee was refuting a "whole idea" that no one holds (to my knowledge).
            >
            >

            Brain size and body size have no signifant correlation from any of the
            autopsy data I've seen, so why, within species, would it have to corrected
            for?


            Ralph L. Holloway
            Dept. Anthropology
            Columbia University
            NY, NY 10027
            212-854-4570
            Fax= 212-854-7347
            Web Page www.columbia.edu/~rlh2
          • Fred Weizmann
            As you indicate, Jerison specifically stated that his formula was not applicable to humans. However, that has not stopped people from using it in that way,
            Message 5 of 10 , Sep 1, 2005
              As you indicate, Jerison specifically stated that his formula was not applicable to humans. However, that has not stopped people from using it in that way, often with misleading results. In a 1991 study Phil Rushton used a correction formula in a comparative study of Asian and non-Asian military recruits. Using this correction, Rushton found that the average cranial capacity of a sample of 24 large male samples of East Asian military recruits was 1460 ccs, compared with 1446 ccs for 20 comparable European military samples. However, as Reed and Jenson pointed out, the actual unweighted mean cranial capacity (unweighted because Rushton treated each sample as a single observation) for the Caucasian samples, prior to applying the corrected version of Jerison's formula, was actually larger than that of the East Asian samples.

              Rushton, J. P (1991) Mongoloid-Caucasian differences in brain race from military samples. Intelligence, 351-359.

              Reed, T. E., & Jenson, A. R. (1993). Cranial capacity. New Caucasian data and comments on Rushton's claimed Mongoloid-Caucasoid brain size differences. Intelligence, 407-422.

              Fredric Weizmann


              Jason Malloy wrote:
                Julian O'Dea: Why must there always be an adjustment for 
              body size?  I have never understood the force of this argument. 
              Larger is larger, isn't it?  
                  
              The distinction has proved meaningful in the evolutionary study 
              of intelligence between absolute brain size and EQ 
              (encephalization quotient) which is a measure of brain size over 
              and above what is predicted from body size (or what is 
              considered needed for basic "house-keeping"). The 
              assumptions pan out rather well. Harry Jerison's 'Evolution of the 
              Brain and Intelligence' is still a classic:
              
              http://www.amazon.com/exec/obidos/tg/detail/-/0123852501/
              
              That's for between-species comparisons. Now within-species, 
              or at least within the human species this doesn't appear to be 
              the case (but again the IQ/brainsize correlation in humans may 
              be spurious). Here are statements from the 'Handbook of 
              Human Intelligence':
              
              "Brain size is not related to body size in humans"
              
              pg 241 chapter 11. H. Jerison
              
              "contrary to what is sometimes claimed, no study of brain 
              volume (or head size) has shown a substantial decrement in 
              correlation after partialling out either height or weight (or both)"
              
              pg 246 chapter 12. P. Vernon et al
              
              http://www.amazon.com/exec/obidos/tg/detail/-/0521296870/
              
              
                
                As for the intelligence of Homo floresiensis, as I pointed out 
              at the annual meeting of the Australasian Society for Human 
              Biology last year, parrots and other birds are proving to be 
              surprisingly intelligent despite their small brain size.  
              Presumably it is a matter of efficient packaging.
                  
              No birds have small bodies, and homo floresiensis has a very 
              low EQ. Here's Richard Dawkins:
              
              "Biologists expect small animals to have small brains anyway 
              and they have developed ways of calculating this. The EQ or 
              Encephalisation Quotient is a measure of how much bigger (or 
              smaller) a brain is than it "ought to be" for its body size, given that 
              it is, say, a mammal. 
              
              Calculated in this way, modern humans have an EQ of about 6, 
              meaning that our brain is six times as big as it "ought to be" for a 
              mammal of our size. Homo erectus is believed to have an EQ of 
              about 4, and Australopithecus (our probable ancestors of about 
              3m years ago) about 2.5 or 3 (similar to a modern chimpanzee). 
              Flores woman comes into the same range as Australopithecus 
              or modern chimpanzees. "
              
              http://www.timesonline.co.uk/article/0,,2092-1336836_1,00.html
              
              So Flores has tools like an erectus but is encephalized like a 
              chimp or Lucy. As for birds, EQ matters, as a big study that just 
              came out this year shows:
              
              "They gathered data on brain mass for 1,967 species.
              
              In more than 600 introductions of nearly 200 bird species into
              new habitat they found that species with brains large relative to
              their body size tended to survive better in new environments than
              smaller-brained birds.
              
              Examples include the introduction in the 19th century of the
              European starling to North America.
              
              "Overall, our results provide strong evidence for the hypothesis
              that enlarged brains function, and hence may have evolved, to
              deal with changes in the environment," they wrote in this week's
              issue of the Proceedings of the National Academy of Sciences.
              
              The researchers last month published an IQ index guide to birds
              that show corvids — birds from the crow family including ravens
              and jays — are by far the cleverest birds.
              
              Next on the list are hawks, woodpeckers and herons, while
              partridges, new world quails, emus and ostriches are the dolts
              of the bird world."
              
              www.hindustantimes.com/news/181_1281672,00040010.htm
              
              This study is interesting because it added external validity to 
              animal intelligence tests (similar in content to human 
              intelligence tests) which also showed a connection between bird 
              species performance and EQ (same for primates). 
              
              
              
              
              
              
              
               
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            • Ralph L Holloway
              ... We are talking about within-species correlations are we not, or have I missed something? As for Jerison s magnum opus, I reviewed it for Science in 1974,
              Message 6 of 10 , Sep 1, 2005
                On Thu, 1 Sep 2005, Jason Malloy wrote:

                >> Julian O'Dea: Why must there always be an adjustment for
                >> body size? I have never understood the force of this argument.
                >> Larger is larger, isn't it?
                >
                > The distinction has proved meaningful in the evolutionary study
                > of intelligence between absolute brain size and EQ
                > (encephalization quotient) which is a measure of brain size over
                > and above what is predicted from body size (or what is
                > considered needed for basic "house-keeping"). The
                > assumptions pan out rather well. Harry Jerison's 'Evolution of the
                > Brain and Intelligence' is still a classic:

                We are talking about within-species correlations are we not, or have I
                missed something? As for Jerison's magnum opus, I reviewed it for Science
                in 1974, and can send you a pdf of the review if you want it.
              • Ralph L Holloway
                ... In 1980, I published a re-analysis of the danish brain weight data in Am. J. Phys. Anthro., specifically to show the range of variation in one very large
                Message 7 of 10 , Sep 1, 2005
                  On Thu, 1 Sep 2005, Fred Weizmann wrote:

                  > As you indicate, Jerison specifically stated that his formula was not
                  > applicable to humans. However, that has not stopped people from using it in
                  > that way, often with misleading results. In a 1991 study Phil Rushton used a
                  > correction formula in a comparative study of Asian and non-Asian military
                  > recruits. Using this correction, Rushton found that the average cranial
                  > capacity of a sample of 24 large male samples of East Asian military recruits
                  > was 1460 ccs, compared with 1446 ccs for 20 comparable European military
                  > samples. However, as Reed and Jenson pointed out, the actual unweighted mean
                  > cranial capacity (unweighted because Rushton treated each sample as a single
                  > observation) for the Caucasian samples, prior to applying the corrected
                  > version of Jerison's formula, was actually larger than that of the East Asian
                  > samples.

                  In 1980, I published a re-analysis of the danish brain weight data in Am.
                  J. Phys. Anthro., specifically to show the range of variation in one very
                  large sample of these derived encephalization coefficients. In our recent
                  2004 book, I show just how variable these EQ's are, not in human, but also
                  ape samples. The human sample had reliable body weights, and I tried
                  partial correlations, made no difference as I recall. I cannot underline
                  enough, that these EQ's are meaningless if used within-species.

                  Ralph L. Holloway
                  Dept. Anthropology
                  Columbia University
                  NY, NY 10027
                  212-854-4570
                  Fax= 212-854-7347
                  Web Page www.columbia.edu/~rlh2
                • Jason Malloy
                  ... No, actually I didn t indicate that, and Jerison specifically stated the opposite: Before reviewing the evidence [for EQ in evolution], let me foreshadow
                  Message 8 of 10 , Sep 1, 2005
                    --- In evolutionary-psychology@yahoogroups.com, Fred
                    Weizmann <weizmann@y...> wrote:
                    > As you indicate, Jerison specifically stated that his formula was
                    >not applicable to humans. However, that has not stopped
                    >people from using it in that way,

                    No, actually I didn't indicate that, and Jerison specifically stated
                    the opposite:

                    "Before reviewing the evidence [for EQ in evolution], let me
                    foreshadow my conclusion that are most relevant for human
                    intelligence. Most of my conclusions are about between-species
                    relationships, but I will report that there is, indeed, a small
                    correlation between brain size and intelligence for psychometric
                    definitions of human intelligence (Willerman, Scultz, Rutledge, &
                    Bigler, 1991). The puzzling decoupling of within from
                    between-species variation that I discussed in the first edition of
                    this chapter is no longer a puzzle. It does not exist. The
                    correlation, though low, is appropriate for our views of the
                    heritability of human intelligence, and its discovery solves a
                    scientific problem."

                    'Handbook of Human Intelligence', p 220.

                    http://www.amazon.com/exec/obidos/tg/detail/-/0521296870/

                    And if we must, Jerison does gingerly allude to the race
                    differences in brain size and cites Rushton's data approvingly:

                    "there are real race differences in brain size (Rushton 1995) . . .
                    but it is difficult to know what to make of them . . . Race
                    differences, which from the brain size data should be much
                    smaller, are simply not discussable in any scientific forum."

                    p. 241

                    His comment that they "should be much smaller", is not an
                    off-hand critique of the data quality, btw, but an abbreviation of
                    the thought "they should be much smaller assuming no
                    intelligence differences and standard EQ data interpretation". He
                    leaves room pending further evidence, and improved academic
                    attitudes, as do I. Never the less, scientists must make choices
                    about the most promising research paths in which to invest time
                    and money. Be it in animals or man, I suggest evo-bio research
                    paths following assumptions of substantial population
                    differences will find more interesting data to build on than those
                    following assumptions of none. As of now I seem to be correct. I
                    would hope any criticism of race research was done in a
                    constructive manner, instead of a nihilisitic one, as is so often
                    the case.
                  • Elaine Morgan
                    ... From: Jason Malloy To: Sent: Thursday, September 01, 2005 4:19 PM Subject: [evol-psych] Re:
                    Message 9 of 10 , Sep 2, 2005
                      ----- Original Message -----
                      From: "Jason Malloy" <jmalloy@...>
                      To: <evolutionary-psychology@yahoogroups.com>
                      Sent: Thursday, September 01, 2005 4:19 PM
                      Subject: [evol-psych] Re: Re: IQ tests



                      "Overall, our results provide strong evidence for the hypothesis
                      that enlarged brains function, and hence may have evolved, to
                      deal with changes in the environment," they wrote in this week's
                      issue of the Proceedings of the National Academy of Sciences.

                      This I like. It suggests that our ancestors - compared to those of the
                      chimpanzees -
                      were subjected to a much more radical change in their environment.
                      Not long ago we learned that bipedalism arose
                      before the savannah ecosystem existed, so the radical change to
                      life on the plains cannot have been responsible.

                      Some other radical change must have happened to them, no? Can anybody
                      recommend any
                      peer-reviewed papers suggesting what it may have been?

                      Elaine
                    • Mark Flinn
                      It is possible that the radical change in their environment associated with the three-fold increase in brain size for hominins may have involved different
                      Message 10 of 10 , Sep 2, 2005
                        It is possible that the "radical change in their environment" associated
                        with the three-fold increase in brain size for hominins may have involved
                        different specific factors than that associated with the relatively small
                        differences in brain size in birds. IMO we could be looking at apples and
                        oranges here. Different parts of the brain are used for different cognitive
                        processes. Hominin brains are especially enlarged or changed in those areas
                        associated with social competencies (Adolphs, 2003; Geary 2005). However,
                        brain evolution in some species of birds also may have as much to do with
                        the dynamics of social competition as with physical aspects of the
                        environment (Emery & Clayton 2004; Rothe & Dicke 2005).

                        In regard to the other string on body size and brain size, there are
                        constraints from flying that make such assessments more difficult for birds.
                        An additional factor to consider is the different levels of social
                        competition that are contingent upon ecological dominance (Ward et al 2004).

                        Adolphs, R. (2003). Cognitive neuroscience of human social behavior. Nature
                        Reviews, Neuroscience, 4(3), 165-178.

                        Emery, N.J. & Clayton, N.S. (2004). The mentality of crows: convergent
                        evolution of intelligence in corvids and apes. Science 306, 1903-1907.

                        Flinn, M.V., Geary, D.C., & Ward, C.V. (2005). Ecological dominance, social
                        competition, and coalitionary arms races: Why humans evolved extraordinary
                        intelligence. Evolution and Human Behavior, 26(1), 10-46.

                        Flinn, M.V., Alexander, R.D., & Coe, K. (200x). Runaway social selection:
                        The linked red queens of human cognition, coalitions, and culture. In
                        The evolution of mind, S.W. Gangestad & J.A. Simpson (Eds.), New York:
                        Guilford press.

                        Geary, D. C. (2005). The origin of mind: Evolution of brain, cognition, and
                        general intelligence. Washington: American Psychological Association.

                        Roth, G. & Dicke, U (2005). Evolution of the brain and intelligence. TRENDS
                        in Cognitive Sciences, 9(5), 250-257.

                        Ward, C.V., Flinn, M.V., & Begun, D. (2004). Body size and intelligence in
                        hominoid evolution. In: The evolution of thought: Evolutionary origins of
                        great ape intelligence, A.E. Russon & D.R. Begun (Eds.), pp. 335-349.
                        Cambridge: Cambridge University Press.

                        On 9/2/05 10:06 AM, "Elaine Morgan" <elaine@...> wrote:

                        >
                        > ----- Original Message -----
                        > From: "Jason Malloy" <jmalloy@...>
                        > To: <evolutionary-psychology@yahoogroups.com>
                        > Sent: Thursday, September 01, 2005 4:19 PM
                        > Subject: [evol-psych] Re: Re: IQ tests
                        >
                        >
                        >
                        > "Overall, our results provide strong evidence for the hypothesis
                        > that enlarged brains function, and hence may have evolved, to
                        > deal with changes in the environment," they wrote in this week's
                        > issue of the Proceedings of the National Academy of Sciences.
                        >
                        > This I like. It suggests that our ancestors - compared to those of the
                        > chimpanzees -
                        > were subjected to a much more radical change in their environment.
                        > Not long ago we learned that bipedalism arose
                        > before the savannah ecosystem existed, so the radical change to
                        > life on the plains cannot have been responsible.
                        >
                        > Some other radical change must have happened to them, no? Can anybody
                        > recommend any
                        > peer-reviewed papers suggesting what it may have been?
                        >
                        > Elaine
                        >
                        >
                        >
                        >
                        >
                        >
                        >
                        > Yahoo! Groups Links
                        >
                        >
                        >
                        >
                        >
                        >
                        >

                        Mark Flinn
                        Departments of Anthropology
                        and Psychological Sciences
                        University of Missouri
                        Columbia, MO 65211
                        (573) 882-9404
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