Sunday, July 1, 2007

Further objections!!!

Objections range from the simplistic nature of 'g', through to the relative stability of the correlations and factor analysis to determine it. Another argument was that as it ignored group factors in test scores (corresponding to broad abilities such as spatial visualization, memory and verbal ability) that may also be found through factor analysis.

Some consider Gardner's theory of "multiple intelligences" to be a weak counter argument:

Stephan Jay Gould, a paleontologist, published The Mismeasure of Man (1981) that was a highly controversial book, that looked like this:

He wrote a history that analyzed the methods and reasons to take a biologically determined approach, such as that proposed by Spearman and Jensen with their g-factor theories. He argued that the fallacy of psychometric testing is that is ranks people in an ascending order, which is in stark contrast to evolutionary theory for complex variation.

According to Gould these methods suffer from "two deep fallacies." The first fallacy is of reification, that is, "our tendency to convert abstract concepts into entities." These entities include IQ (the intelligence quotient) and g (the general intelligence factor), which have been the cornerstone of much intelligence research. The second fallacy is one of ranking, or our "propensity for ordering complex variation as a gradual ascending scale."

Philip Kitcher wrote in 1985:

Many scientists are now convinced that there is no single measure of intellectual ability - no unitary intelligence. Their suspicion of the concept of general intelligence is based on the view that various intellectual capacities are not well correlated. is useful to continue to expose the myth of "general intelligence".

However, views that dismiss "g" as entirely fictional or irrelevant are controversial. Most psychometricians still recognize and employ "g" as a valid and coherent evaluation of human mental ability.

Recently, researchers in the area of AI (aritificial intelligence) claim that the study of mental ability is like "computationalism" and thus of no real purpose, as cognitive ability tests only measure individual differences that are/will one day, be undertaken by computational mediums, such as personal computers and robots. As such, mental abilities have nought to do with intelligence.


More support...however...

But we do know that, wherever freedom and technology advance, life is an uphill battle for people who are below average in proficiency at learning, solving problems and mastering complexity. We also know that the trajectories of mental development are not easily deflected. Individual IQ levels tend to remain unchanged from adolescence onward, and despite strenuous efforts over the past half a century, attempts to raise g permanently through adoption or educational means have failed. If there is a reliable, ethical way to raise or equalize levels of g, no one has found it (Gottfredson, 2006).

However, such a view ignores the capitalist philosophy that industrialized societies function by; information is withheld from those who "don't know" so as to maintain power imbalances (1); circumstances such as poverty, experiences of prejudice and stereotyping denying equality of outcomes, let alone equality of access to opportunities and resources (2), are ignored as to their influence on affecting a person's IQ.

The view also ignores that those of us "living in freedom" experience the highest rates of depression (3), suicide (4), are amongst the nations with the highest poverty levels (outranking even those of some developing nations) (5), have populations that are slaves to consumption unable to save (6), most citizens live in debt (7), and are obligated to work in order to survive in our commercial culture (8). The view also assumes that technological "advances" are a positive, neglecting to contemplate the near extinction of our species due to pollution, destabilization of eco-systems, and salient examples of inhumanity for social power and profit (9).


Gottfredson, L.S. (1998). The General Intelligence Factor. Scientific America, Retrieved June 29, 2006, from










Galton a foundation stone

Galton (1869) provides an agreeable foundation to Jensen and Spearman's views:

"People lay too much stress on apparent specialties, thinking over rashly that because a man is devoted to some pursuit he could not possibly have succeeded in anything else. They might just as well say that because a youth had fallen desperately in love with a brunette, he could not possibly have fallen in love with a blonde. He may or may not have more natural liking for the former type of beauty than the latter, but it is as probable as not that the affair was mainly or wholly due to a general amourousness of disposition. It is just the same with special pursuits. A gifted man is often capricious and fickle before he selects his occupation, but when it has been chosen he devotes himself to it with a truly passionate ardour. After a man of genius has selected his hobby, and so adapted himself to it as to seem unfitted for any other occupation in life and to be possessed of but one special aptitude, I often notice, with admiration, how well he bears himself when circumstances suddenly thrust him into a strange position. He will display an insight into new conditions, and a power of dealing with them, with which even his most intimate friends were unprepared to accredit him. Many a presumptuous fool has mistaken indifference and neglect for incapacity; and in trying to throw a man of genius on ground where he was unprepared for attack, has himself received a most severe and unexpected fall. I am sure that no one who has had the privilege of mixing in the society of the abler men of any great capital, or who is acquainted with the biographies of the heroes of history, can doubt the existence of grand human animals, of natures pre-eminently noble, of individuals born to be kings of men".



Arthur Jensen (1923- )

"Any explanation of the secular change in IQ test raw scores must take account of the fact that, unlike the population means, there are certain properties of the IQ that have remained virtually constant across the past sixty or seventy years. These include its reliability, its correlations with measures of other psychometric abilities, its G loading, and its external validity…" Also Jensen, using Spearman's rho (a powerful statistical tool), showed that the increases in test scores have nothing to do with the G-loadings of the tests (in other words, more G does not mean more Flynn effect). The Flynn effect is probably due to a group factor that cuts across the traditional structure of abilities: most G-loaded tests would "carry" the Flynn factor to a significant degree (like a parasite). This group factor has not been identified precisely but a decrease in field dependence is probably involved. To be stressed here is the established fact that superior performance in cognitive tasks that require field independence carries no implication about competence in other classes of cognitive tasks" (p. 322).

Jensen, A. R. (1998). The g factor: The science of mental ability. Westport, CN: Praeger.

Jensen wrote extensively that IQ is genetic in origin and can explain the "Black-White" IQ gap. He highlighted the neglected issue of the part genetics could play in the formation of intelligence.

Jensen published his book The g-factor: The science of mental ability (1998), supported the initial investigations of Spearman. Some consider the book the pinnacle of research fundamentals for future endeavors on the topic of g.



The point made by Spearman was that the tests that loaded onto the g-factor (correlated highly with the factor in a Factor Analysis) did so relative to the degree of mental complexity involved to solve them.

Hence... the most ideal measures of the g-factor appear to be those that require a person to compare, choose, analyze and synthesize, or to infer correctly. Judgment and invention have been touted as synonyms for g-factor.


Tests that tap g-factor

Do some tests tap into g-factor more so than others ....

Raven's Progressive Matrices
information about the tests:

similar test:

Elementary Cognitive Tasks

memory search paradigm:

mental rotation task:

posner paradigm:

happy reading and gaming :-)

The two factors of intelligence

Spearman concluded that two factors of intelligence existed:

1. A single general factor, the g factor (correlations)


2. Numerous specific factors, s1, s2, ... (differences across test scores).

The blue ovals represent individual mental tests,
areas shaded blue are due to variance of s,
and the areas shaded purple are due to the variance of g.

The IQ score was determined to be an accurate measure of mental development and of general cognitive functioning.

As such, IQ would indicate the average of the specific factors canceling each other out~ highlighting the g-factor.