Well, I have my PhD in psychometrics; I am (relatively speaking) a defender of IQ tests. And, by and large, I agree with the statements John Kulig makes here. But, when a serious person can seriously say
"we can measure it better than we can define it" then we know that there is some problem. (I am NOT saying the statement is incorrect, only that it is indicative of a general confusion in the field) When we go further and try to correlate this murky thing called intelligence with ANOTHER murky thing called 'real world success' then we are really on a slippery slope. When we insist on imposing linearity on this relationship, and we do this ACROSS fields, and then meta-analyze the results.....then.....welll.....GIGO. One measure of 'success' is income. Here, I have seen studies that show a curvilinear relationship between IQ and income, largely because the highest paying jobs (CEO and the like) are usually taken by people with modestly high IQs (in the 130 - 140 range, IIRC). And the highest IQ people often enter professions that are NOT that high paying (e.g. academia and research), but which offer other rewards But, of course, income is only one measure of success. Success WITHIN a field may be related to IQ (probably is) but the relationship probably varies from field to field, and is unlikely to be linear in ANY field; and, in most fields, may not even be monotonic. Peter Peter L. Flom, PhD Assistant Director, Statistics and Data Analysis Core Center for Drug Use and HIV Research National Development and Research Institutes 71 W. 23rd St www.peterflom.com New York, NY 10010 (212) 845-4485 (voice) (917) 438-0894 (fax) >>> [EMAIL PROTECTED] 4/26/2004 3:18:22 PM >>> There is a tremendous amount of scientific literature on the measurement of intelligence, much of it unknown outside the discipline, even amongst psychologists from other specialties. Gardner's multiple intelligences is not held in the highest esteem in the field. You don't see well developed operational definitions with high reliabilities and validities for his various intelligences (which might be better described as talents or abilities). On the g issue, correlations between real-world success and "intelligence" is highest when the test is heavily loaded on g (e.g. Raven test). Contrary to what a previous person said about the Raven test, one does not memorize the answers (there is nothing to memorize). Some "g" items look like they might involve memorized material, actually do not. This is an arithmetic reasoning item (not a Raven item) that would contribute to g: "Bob is twice as old as his sister, who is now 7. How old will Bob be when his sister is 40?" The "math" is not the issue - it's the ability to represent the elements symbolically and co-ordinate the different parts of the problem. People more "heavily load" with g can do these faster and more efficiently. Though in fairness to critics, we can measure intelligence better than we can define it (i.e. we can show it "by site if not by nature").Tests that utilize more rote memory are lower and g, and, show worse psychometric properties, such as validity coefficients. The fact that factor analysis was involved in demonstrating g lead many people to view it as a statistical abstraction only, but the collective evidence suggests this is not so. For years people used to claim g did not correlate that well with "real world" success, but studies with large N show a remarkable effect of g. Ree & Earles (1990) "Differential validity of a differential aptitude test" AFHRL-TR-89-59 (Brooks AF Base, TX) reports % of "training success" in different military specialties explainable by g (I round to nearest %). Nuclear weapons specialist 77% (i.e. rocket scientist!) Weather specialist 70% Fireman 60% Vehicle maintenance 49% Maintenance 28% [to mention a few] Hunter and Hunter's meta-analysis (1984 Psych Bulletin) across a wide variety of professional occupations finds cognitive test score (i.e. IQ) the best overall predictor (r = .53); second is biographical data r = .37, and college grades is a feeble .11! Interestingly, twin studies find that of all the major components of intelligence, g is the most heritable. Psychometrics is an interesting aspect of psychology. The "controversies" regarding these tests _outside_ the field belies the consensus within the discipline regarding the definition and measurement of intelligence. ============================================ John W. Kulig Professor of Psychology Plymouth State College Plymouth NH 03264 ============================================ . . ================================================================= Instructions for joining and leaving this list, remarks about the problem of INAPPROPRIATE MESSAGES, and archives are available at: . http://jse.stat.ncsu.edu/ . =================================================================
