Thoughts and quotes concerning the nature of intelligence.
MULTIPLE INTELLIGENCES
Anyone interested in the topic of multiple intelligences may also be interested to look up the comments on the subject offered by R. L. Smith in the December 1996 Mensa Bulletin (P.8). He points out that multiple intelligences is a vehicle by which any virtue or talent can be defined as intelligence. He wrote: "This whole notion trashes the concept of the gifted classes, which were designed for the needs of very intelligent students... It changes the program from one with a purpose to one without."
A few scholars actually believe that there is merit in the multiple intelligences concept, but the majority do not. I previously referenced the Snyderman-Rothman survey, reported in 1988. 67% of the scholars in that survey supported the g-based model of intelligence; 15% preferred a separate abilities model; the remainder were unsure.
It is my belief that the separate intelligences model is the construction of PC liberals who wish to create warm feelings that everyone is "special." I continue to believe Miller's Myelination Hypothesis is likely to hold as a mechanistic explanation of the validity of Spearman's g.
The following comments by Charles Murray appeared in Skeptic vol. 3, no. 2, 1995, pp. 34-41:
"Let me make a couple of other points about intelligence. One, the general mental factor, g, is very robust. You can take all kinds of different ways of creating your factors, and you will always get g. It doesn't matter whether rotate the matrix orthogonally, or obliquely, or whatever else, you always get the same thing. The second major point is that when you try with factor analysis to produce a situation where you do not have a general mental factor g, guess what? All the factors are correlated. Which goes back to Spearman's initial insight, which is why are the different measures of mental ability so consistently correlated with each other? What's going on here? The answer is: there is an underlying general factor."
"Gardner has made a variety of assertions about intelligence which, if true, are falsifiable. He is not only saying there are different talents, which Dick Herrnstein and I would agree with, he is also saying they are independent. With something like kinesthetic talent, which is quite physical, this is easy to say. It gets harder to say when he talks about interpersonal skills, versus verbal skills. If you are going to make that kind of statement, the next logical step is to come up with measures of these different talents and demonstrate that they are, in fact, independent."
"Gardner has consistently been unwilling to subject his own work to that kind of empirical defense. He has stood apart from quantitative attempts to describe what he is doing and to enable other researchers to replicate it. Of all the different types of intelligence that Gardner wants to treat as co-equals, there is only one kind that will put you in the retarded class--namely the plain old fashion general mental ability. If you are kinesthetically challenged, teachers and guidance counselors do not get real worried about you. If you are kinesthetically challenged you may be the last person chosen for the baseball team, but you can go out and make a success of yourself in any number of ways. If you are intellectually challenged, however, you have a general disability that is pervasive over all kinds of ways."
Concerning the low intelligence of Muhammad Ali:
"If you are five standard deviations out on the edge of the curve in kinesthetic ability to the right hand side, then certain possibilities open up to you. But if you are low in kinesthetic ability, it doesn't make much difference to you in life. If you are a Muhammad Ali and you possess extraordinary physical talent, you have other avenues that will open up to you. But this example illustrates another important point, which is that Muhammad Ali is not a blithering idiot. Yet there is nothing in his public utterances, his charm, his presence, his charisma, and all the rest of that, that is inconsistent with a measured I.Q. in the high 70s."
INTELLIGENCE DIFFERENCES BETWEEN THE SEXES
The IQ distribution for men and women is not the same. The bell curves associated with each have the norm at 100, but if you calculate the standard deviation of the female curve, it will be smaller than the standard deviation for males. The result is that there will be more very bright males than females and more very dumb males than females.
A few sources of information to support this observation:
"While both sexes have average scores of 100, the men's scores include more extreme cases. Men are overrepresented among the super smart--above IQ 140 there appear to be at least 20% more men than women." from STRAIGHT TALK by A. Jensen, p. 249. Note that others have estimated a greater spread. Eysnck (THE INTELLIGENCE CONTROVERSY) states that there are 37% more men at IQ levels above 132.
"20% more men than women score above IQ 140 and below IQ 60."
[Daniel Seligman, 1992. A Question of Intelligence, Carol Publishing Group.]
The subject is discussed at length in WOMEN AND GENDER: A FEMINIST PSYCHOLOGY, by Unger and Crawford, 1992, McGraw-Hill.
Women can do math and physics, but the numbers of them who have top level abilities in these areas are fewer than for men. This subject has been dealt with in lots of scientific papers. For example, David Lubinski and Camilla Persson Benbow wrote [Current Directions in Psychological Science, Vol 1, No. 2, April 1992]: "Males tend to excel in physics, political science, European history, computer science, and chemistry, among other areas, whereas females are superior to males in English and the foreign languages." They reported the following ratios of males to females at various cut points on the SAT-M:
above 500 ratio 2/1
above 600 ratio 4/1
above 700 ratio 13/1
This paper includes volumes of data to support each observation and notes: "A large body of data suggests that mechanical and spatial abilities have special importance for satisfactoriness in engineering and the physical sciences; investigative-theoretical interests and values are important for personal satisfaction int these disciplines. ... males tend to have ability and preference profiles more congruent with optimal adjustment in math and science careers."
INTELLIGENCE AND RACE
I don't know how many hypotheses have been developed to explain the observed differences in intelligence between the races, but I am familiar with two:
Richard Lynn -- Suggested that Mongoloid intelligence evolved from the stresses of the Ice Age. He has discussed the geographical isolation of the Mongoloids and the heightened demands for hunting success under Ice Age conditions and suggested that these combined to produce the high spatial abilities that remain among Mongoloids. He argued that the present low verbal abilities of this group were the consequence of a trade-off that occurred within the brain (basically that spatial abilities had such importance for survival that they displaced verbal real estate, especially in the male Mongoloids).
One source of his ideas: The Intelligence of the Mongoloids: A Psychometric, Evolutionary and Neurological Theory; Personality and Individual Differences, 1987, 8, 813-844.
J. Phillippe Rushton -- Developed the theory of reproductive strategy as the basis for racial differences has been the subject of a lot of criticism, mostly by ignorant nonscientific pontificators. His work is serious (whether right or wrong) and not motivated by bigotry. Some of his papers:
1985 - Differential K theory and race differences in E and N. Personality and Individual Differences 6, 769-770.
1987 - Rushton and Bogaert, Race differences in sexual behavior: Testing an evolutionary hypothesis. Journal of Research in Personality 21.
1994 - Race, Evolution, and Behavior: A life History Perspective. Transaction Publishers, New Brunswick, NJ
Is either explanation correct?
THE BELL CURVE
The book contains three categories of material:
1. A good summary of scientific findings on the subject of intelligence. It took 57 pages to list the source materials. People who had been reading peer reviewed journals on the subject of intelligence were not surprised by any of this material. It was all well known prior to the publication of BC and most of it was assembled and published in Seligman's book, A Question of Intelligence.
2. An analysis of the National Longitudinal Study of Youth was done by the BC authors. Their analysis was of high professional quality.
3. Issues were discussed as suggestions and opinions of the authors (in the last part of the book). These were not presented as facts, but as opinions.
APTITUDE TEST OR INTELLIGENCE TEST?
The Bell Curve: "The SAT was originally designed to be an intelligence test targeted for the college-going population and was originally validated against existing intelligence tests. For a modern source showing how carefully the College Board avoids saying the SAT measures intelligence while presenting the evidence that it does, see Donlon 1984."
Donlon, T.E. 1984. THE COLLEGE BOARD TECHNICAL HANDBOOK FOR THE SCHOLASTIC APTITUDE TEST AND ACHIEVEMENT TESTS. New York: College Entrance Examination Board.
In Seligman's A QUESTION OF INTELLIGENCE, he wrote: "Many tests not formally labeled IQ tests nevertheless give a pretty good measure of IQ" The first example he gave was the SAT. I have to assume that the admission officers of the high IQ societies agree, or else they would not have agreed to accept pre-1994 SAT scores.
Correlations between standard IQ tests are usually in the 0.7 to 0.8 range. Examples:
WAIS to S-B = 0.77
WAIS to Raven's = 0.72
WAIS to Otis = 0.78
WAIS to SAT = 0.80
The designers of the SAT benchmarked it against the Otis; the similarity of correlations between these and the WAIS was no accident.
If we are to argue that the old SAT is not an IQ test, then the above correlations present a problem. Should the WAIS be tossed out as an inappropriate test instrument? If not, then are the S-B, Raven's, and Otis unreliable (since they correlate at lower levels than the SAT)?
Anyone interested in a massive history of the development of the SAT should consider reading The Great Sorting, September, 1995, The Atlantic Monthly.
DISGENICS
There is an interesting article in the June 2, 1997 issue of Forbes: The educated mom syndrome. It is partly based on the contents of professor Richard Lynn's new book DISGENICS: GENETIC DETERIORATION IN MODERN POPULATIONS (Praeger). Lynn teaches at the University of Ulster and is known for his theory which attempts to explain Mongoloid intelligence in the basis of Ice Age stress and evolution.
The Forbes article shows that the only IQ group that is reproducing with a birthrate above the replacement rate (2.1) is the group from IQ 85 to IQ 100. Women with IQs above 130 have a rate of 1.77; only 13 years ago, this group averaged less than 1.0. Women in the 116 to 130 range had a rate of 1.78.
MYERS-BRIGGS TEST
From the December 1993 Mensa Bulletin:
Category: E/I S/N T/F J/P
Overall population: 75/25 75/25 55/45 50/50
Mensans: 27/73 10/90 75/25 65/35
These data show that Mensans are most likely to be INTJ (me, for example). 32% of Mensans would be INTJ, while only 1.4% of the overall population would be INTJ. That is a HUGE difference. American Mensa
FLYNN EFFECT
IQ test scores have been rising in industrialized countries for the past 50 years. The phenomena was identified by James Flynn and is known by his name. Although psychometricians have theories as to why this has happened, they do not agree on any explanation and it remains to be properly understood. The score shifts due to the Flynn Effect make it necessary to frequently renorm IQ tests.
Note that the scores are increasing. This may or may not mean that intelligence is increasing. There are good reasons to believe that average intelligence is not increasing at the rates IQ scores have been increasing.
"Young adults in 1980 outscored the young adults of 1950 by about18 points on Raven's, 15 points on Wechsler...and 11 points on purely verbal tests. These trends hold for every nation for which we have data..." [James Flynn, IQ TESTS AND CULTURAL DISTANCE; Research Information for Teachers, no. 2 (1990), pp. 2-4.]
From Murray and Herrnstein An Apologia in The New Republic: "The Flynn effect was identified in the 1930s when testers began to notice that IQ scores often rose with every successive year after a test was first standardized. For example, when the Stanford-Binet IQ was restandardized in the mid-1930s, it was observed that individuals earned lower IQs on the new tests than they got on the Stanford-Binet that had been standardized in the mid-1910s; in other words, getting a score of 100 (the population average) was harder to do on the later test. This meant that the average person could answer more items on the old test than on the new test. Most of the change has been concentrated in the nonverbal portions of the tests."
"The tendency for IQ scores to drift upward as a function of years since standardization has now been substantiated in many countries and on many IQ tests besides the Stanford-Binet. In some countries, the upward drift since World War II has been as much as a point per year for some spans of years. The national averages have in fact changed by amounts that are comparable to the fifteen or so IQ points separating whites and blacks in America."
An interesting comment from The Bell Curve:
"No one is suggesting, for example, that the IQ of the average American in 1776 was 30 or that it will be 150 a century from now. If the mean IQ in 1776 had been 30 and the standard deviation was what it is today, then America in the Revolutionary period had only 5 men and women with IQs above 100."