Various Theories of Intelligence
There are three theories of intelligence which explain the nature of intelligence:
1. Spearman's Two-Factor Theory
The English Charles Spearman (1904), who was the inventor and first user of factor analytic methods, developed a two-factor theory of intelligence from his own experimental work.
The theory was expounded in his book "The Abilities of Man ". This book was published in 1927.
The essence of his theory in his own words was, "That all branches of intellectual activity have in common on fundamental- function (or group of functions), whereas remaining or specific elements of the activity seem in every case to be wholly different from that in all the others."
We can say that on the basis of this intelligence is composed of two factors-one 'g' factor and the other's' factor. This 'g' factor is involved in all walks of life end's' is a special factor which is exclusive and is shared by none. The Examples of' factor is: Artistic ability, 'Musical ability'. These 'special abilities' are independent of 'g' factor. There are 9's' factors.
Spearman wisely refused to identify 'g' with intelligence or any other quality whose definition was controversial; he suggested that it depends upon the general mental energy with which each individual is endowed.
They factors he compared to a large number of mechanisms or Engines which could be activated by this energy. "S" are largely affected by education and training whereas 'g' is innate as well as in educable.
The chief criticism that can be raised against Spearman's work is that he failed to allow sufficiently for types of abilities, which while less general that 'g', are certainly not specific.
The reason was that he was unable to get at 'group factors' and his samples were small. Towards the end of his life, Spearman had begun to realize the existence of 'group factors' but could not formulate his views.
2. Thomdike's Multi-Factor Theory
E.L. Thomdike's multi- factor theory stands in sharp contradiction of Spearman's two-factor theory. According to this, intelligence is a name conveniently given to infinite number of specific abilities combined together.
It can be stated that intelligence is the sum total of all the specific capacities with regard to every separate act. It also means that E.L. Thorndike denies the existence of a general factor. Intelligence is a host of highly independent factors. This theory was given to us in the beginning of the present century.
Types/Kinds of Intelligence
Thorndike concluded that there were three types of Intelligence:
(i) Social Intelligence of ability to understand and deal with persons.
(ii) Concrete Intelligence referring to dealing with things, as in skilled trades and specific appliances.
(iii) Abstract Intelligence or ability to understand and deal with verbal and mathematical symbols
Abstract intelligence is the one that receives the greatest weight.
3. Thurstone's Group-Factor Theory
Intermediate between the theories of Spearman and Thorndike is the Group-Factor Theory or the P.M.A. (Primary Mental Abilities). Theory given to us by Thurstone
It was in the year 1938, that Thurstone gave us this theory after giving 56 types of tests to students of Chicago University. All these results were subject to factor analysis. He concluded that in all these tests, seven types of factors were working, i.e., Intelligence is composed of those seven primary mental abilities which are working in all tests.
Thurstone does not believe in 'G' and 'S' theories. Thurstone concludes that certain mental operations have a common primary factor that gives them psychological and functional unity and also differentiates them from other mental operations. These mental operations constitute a group.
A second group of mental operations has its own unifying primary factor, and so on. In all, there are seven such groups which cover the entire range of mental abilities. Each of these primary factors is independent of others.
(1) V-Verbal (2) N-Number (3) S-Spatial (4) W-Word F-frequency (5) R-Reasoning (6) M-Memory (7) P-Perceptual.
Latest Views on the Nature of Intelligence
Thurstone's Theory has been a subject of lot of research. Two types of research have been made in this connection:
1st: Have these seven primary mental abilities no connection with one another? Is there no 'G' amongst them?
2nd: Are these primary mental abilities absolute? Are they not further reducible?
As far as the first question is concerned, answer has already been given that these are independent of each other. But recently some positive correlations have been found to exist between these abilities.
It means that there is a general factor also. Thurstone admits this in a very clever way by saying there is a second order general factor. These positive correlations were more glaring as far as children were concerned.
Regarding the second question, lot of research has been done to determine their absoluteness. Even Thurstone and his associates now agree that these are not absolute. These abilities can be further split.
The splitting of erstwhile absolute abilities has led to another theory called the Hierarchy Theory, and P.F. Version is connected with it. It was, however, Guilford who first of all split these abilities.
The products are:
The concepts are: