Theoretical Models of Intelligence
Implications of Intelligence
The implications and potential for rebarbative social policies based around a faulty theory of intelligence make it a weighty subject and one of true consequence. Pseudo-scientific theorist have used bad constructs, measured in culturally biased ways to justify the suppression of basic human rights in the 20th century. It has been used to, "prove ," the inferiority of minority ethnic groups, to ostracize and marginalize the already disenfranchised, and to justify the forced sterilization of U.S. citizens.
For these reasons the theories surrounding such a construct can be variegated and hotly contested. These are a few of the main such theories that you will encounter still being taught to psychology students across the western world.
Synapses of Major Theories
Thurstone thought that intelligence could be broken down into mental abilities. He derived these using statistical multifactor analysis. The seven cognitive abilities he recognized were memory, reasoning, verbal meaning, number ability, spatial ability, perceptual speed, and word fluency. He was unable to conclusively show in his research if a general intelligence (g) could be derived from this but did not dismiss the possibility.
Spearman's model was based on two linked factors. He conceptualized that the level of a general intelligence factor (g) was contingent on the specific (s) domain of knowledge being considered. Depending on the subject matter these two factors existed in varying ratio's. For instance knowledge of classic English literature might exist in a 10:1 ratio of (g) general knowledge to specific content matter (s). This denoted a greater weight or significance for the function of general (g) intelligence to that specific (s) area of knowledge. On the other hand certain specific talents were weighted more heavily than general knowledge. For example the ration he ascribed to general knowledge in relation to musical talent was 1:4. This indicates a belief that music talent should be viewed with four times the significance than general knowledge when considering intelligence. It further implies that such prodigal abilities where a mark of truly elevated intelligence.
Vernon's writings about intelligence in the 60's maintained that there was a measurable, over all (g) general intelligence factor but it could only be assessed through a break down of other specific factors which collectively constituted minor factor groups which in turn comprised major factor groups which then composed the general intelligence score. General intelligence broke down in Verbal-Educational and Practical. Verbal-Educational broke down into Verbal ability and Numerical ability. Verbal ability was finally broken down into Vocabulary, Reading Comprehension, and Spelling. Numerical Ability broke down into Logical Reasoning, Arithmetic, and Matrix Reasoning. Measuring these specific factors allowed quantitative understand of the Verbal or Numerical minor group factors which collectively Comprised one of the two major group factors. In the Practical major group factor skills abilities were broken down into Mechanical ability, Spatial ability, and Practical ability. Mechanical ability was assessed by measuring the specific factors Mechanical knowledge, Manipulation and Dexterity, and Object assembly. Spatial ability was measured by assessing Picture arrangement, Block Design, and Symbol search abilities. And Practical ability was divided into tasks that measured the specific factors of Perceptual ability, Memory, and Clerical skills. By measuring these specific factors the minor groups of Mechanical, Spatial, and Practical could be assessed. These in turn constituted the major group of Practical, one of the two major factors which constituted the General Intelligence level. So, by starting with the bottom of the hierarchy each higher level could be assessed until the general intelligence was approximated.
Guildford expanded this model that originally had 120 factors into a 180 factor multi-dimensional model. This model consists of three dimensions or aspects of cognition; operations, content, and products. The operations dimension is composed of those things that Guildford theorized we use to understand phenomena, called operations. These operations included Evaluation, Convergent production, Divergent production, Memory retention, Memory recording, and Cognition. The content dimension, or the ways in which we understand information, is composed of Visual, Auditory, Symbiotic, Semantic, and Behavioral factors. The third dimension, products, are the result of our thought processes and includes the factors Units, Classes, Relations, Systems, Transformations, and Implications. All mental abilities involve some combination of these three dimensions of thought and understanding. Since there are 6 factors in operations, 5 in content, and 6 in products this leaves us with 180 possible combinations of ways in which we take in, process, and assimilate information into our mental schema. This theory though broad and inclusive is somewhat difficult to manage in psycho metric intelligence testing.
Fluid and Crystal Intelligence Model
Cattell, in an attempt to remove cultural bias from intelligence testing found that as he removed those items most associated with what is learned within culture, individual scores of intelligence began to change dramatically. He thus realized that there was a, "raw," intelligence which was not measured by those things that one learns and thus is often quite quantitatively different from the intelligence associated with what is learned. He concluded there were two types of intelligence. One was inborn and culturally neutral and he called this fluid intelligence. The other was a product of our experience, what we had learned, what had been indoctrinated into us by culture, and what motivated us. This he called crystal intelligence. Of the two it is fluid intelligence that is directly genetic. Though fluid intelligence begins to diminish in late middle age, crystal intelligence ever increases with age. So with this inverse growth of fluid and crystal intelligence overall general intelligence remains approximately static over the lifetime.
This list is far from exhaustive. Theories such as Piaget's Cognitive Development and Gardner's Theory of Multiple Intelligences were not even covered, among many others. Intelligence remains one of the most consequential and yet tenuous Psychological constructs that we attempt to measure. Some consider this a fool's errand philosophically yet one cannot deny the reliability and validity found in the statistical analysis of the tests that these theories spawn. Those who score high on tests derived from one theory tend to score high on tests derived from other theories and high score do strongly correlate with intellectual and vocational achievement.