On 23 Apr 2004 09:23:26 -0500, [EMAIL PROTECTED] (Herman Rubin) wrote: > In article <[EMAIL PROTECTED]>, > Richard Ulrich <[EMAIL PROTECTED]> wrote: [ snip, previous topic] RU> > > >IQ, merely for the parts important for living and school, > >incorporates at least 6 dimensions which have been rather > >well demonstrated as independent 'talents' that use different > >parts of the brain. HR> > Yes and no; it has even recently been shown in articles in > strong science journals (NOT psychology or education) that > some aspects require the use of both sides simultaneously. > MRI was used to find out what is happening. > The MRI evidence is statistical and still in its infancy. An accident can selectively kill off one ability. A gene defect can do the same.
> But this does not change the point; I still question whether > there is any remotely fair reason to adjust scores on anything > to resemble a normal distribution. RU> > > >Well-measured IQs below about 80, I once was told by specialists, > >demonstrate trauma or genetic defect. So there is (approximately) > >a normal zero for humans, if you want to think of it that way. HR> > "Genetic defect" is genetic variation, not the absence of a > key gene, or the presence of a bad one. On the usual normal > IQ scale, about 9% are below 80. It goes much lower. Please offer your guess as a guess; which in this case has a tendency towards the racist (sorry): That was my citation of my experts, who (I wanted to be sure) were speaking of named- defects such as trisomies; and defective structures that may be associated with congenital holes in the heart, etc. We were also speaking of careful, appropriate IQ tests, administered one-on-one, by experts, for diagnostic purposes. I know that there are tests that offer a wider range of scores, for other purposes, but I *think* the various psychologists have in mind that same anchor at the bottom. > > BTW, if there are individual genes which can make substantial > differences, the entire basis for normality, the assumption > that enough factors are added for the central limit theorem > to be an excellent (not just good) approximation is destroyed. > As you should see now, I was pointing to 'substantial differences' that do fall off the curve, at the bottom. [snip rest for later] -- Rich Ulrich, [EMAIL PROTECTED] http://www.pitt.edu/~wpilib/index.html . . ================================================================= Instructions for joining and leaving this list, remarks about the problem of INAPPROPRIATE MESSAGES, and archives are available at: . http://jse.stat.ncsu.edu/ . =================================================================
