Thurstone’s theory of the 7 primary mental aptitudes which appeared in the 1920s, is one of the most important psychological models of intelligence that exist.
The differential characteristic of this author in relation to others of the time was his focus on the multiple nature of intellectual aptitudes, thus opposing Spearman’s g factor.
Louis Leon Thurstone (1887-1955) is considered one of the most influential authors in the field of psychometrics. His main contribution is his theory of the 7 primary mental aptitudes who opposed the unitary and hierarchical models of intelligence proposed by other pioneers such as Charles Spearman or PE Vernon.
In a very particular way, Thurstone denied the existence of a general intelligence factor (the famous “g factor”) to which the rest of the cognitive abilities would be subordinated. For this author Intelligence had to be understood as a set of primary mental abilities not reducible to a single higher-level dimension.
Along with authors such as Charles Spearman and Raymond B. Cattell, Thurstone is considered one of the main people responsible for the Establishment of factor analysis methods in psychology These mathematical tests have the objective of identifying the number and structure of the different factors that weigh in some type of psychological measure.
Thurstone’s goal was to find a configuration of intelligence that was faithful to empirical data but remained as simple as possible; that is to say, sought to explain the different abilities that make up intelligence with a few higher order factors. Each of them maintained a strong correlation with a specific type of intellectual tests.
The influence of Thurstone’s work has been very notable in subsequent developments in the psychology of intelligence. Thus, we can find inspiration for the model of primary mental aptitudes in the most recent versions of such important tests as the Wechsler Intelligence Scales and the Stanford-Binet Intelligence Scale.
The 7 primary mental abilities
After his first research, for which he used 56 different intelligence tests, Thurstone identified nine factors or primary mental aptitudes.
Numerous subsequent studies have repeatedly validated 7 of these factors, so we can say that Thurstone’s model has strong measurement ability.
1. Verbal comprehension (factor v)
The verbal comprehension factor is associated with knowledge related to language in all its manifestations; It would therefore include vocabulary, semantics, syntax or pragmatics. The tests that weigh in factor v include tests of reading comprehension, ordering of text segments, spelling, verbal analogies, etc.
2. Verbal fluency (w)
This aptitude can be defined as a person’s ability to emit coherent and structured verbal sequences quickly and naturally. To measure it, various types of tests that involve rapid speech production ; Thus, for example, you could use the classic test of giving names of animals that begin with a certain letter.
3. Numerical aptitude (n)
Numeracy tests consist primarily of basic mathematical calculations: addition, subtraction, multiplication, and division. Although they can be more complex, simple arithmetic calculation tasks are mainly weighted in the n factor; The most relevant aspects are the speed of operations and the precision of responses
4. Spatial aptitude(s)
The s factor is manifested in spatial orientation, in the representation of objects in space or in rotation tasks; Since these are very broad capabilities, they are often spatial aptitude is divided into two or three secondary factors The relevant tests involve predicting movements, comparing figures from different perspectives, etc.
This factor is associated with a specific aspect of memory: the ability to retain associations of pairs of elements Thus, to measure associative memory, tests are used that involve images, words (in visual or auditory format), symbols, etc.; They can be presented in the same form or in combinations of more than one of these materials.
6. Speed of perception (p)
In the p factor, all those cognitive tests that are based on the comparison between different elements or in the identification of structures and sequences. Therefore, the aptitude that Thurstone called “perceptual speed” refers to the speed with which we find similarities and differences between various items.
7. General reasoning (r) or induction (i)
Some of the research that has been carried out on Thurstone’s model partly distinguishes the r factor from the i factor. While the second corresponds to the capacity for inductive thinking (finding general rules with predictive value from a series of elements), “general reasoning” has a more marked mathematical weight.
