Charles Spearman: biography of this experimental psychologist.

We know the life and work of one of the pioneers in the study of intelligence.

Modern psychology and, especially, its experimental branch, would not be the same if it had not been for the great contributions of Charles Spearman.

This English psychologist is widely known in the field of research for his statistical contributions to the study of psychological processes, in addition to being the author of one of the best-known theories of human intelligence in the field.

Let's take a closer look at the life of Charles Spearmanwhose life, by turns of events, went from being aimed at defending his country to focusing on the intellectual aptitudes of human beings.

• Recommended article: "Intelligence: the G Factor and Charles Spearman's Bifactor Theory".

Biography of Charles Spearman

Charles Edward Spearman was born in London, United Kingdom, on September 10, 1863, and died in the same city on September 17, 1945, aged 82.

A late start

Spearman's beginnings in the field of psychology could be considered late, since he started his studies in 1898, when he was 34 years old, and after having been a member of the scientific community for 15 years. and having served for 15 years as an officer in the 2nd Battalion of the Royal Munster Fusiliers in India (1885-1897).

His decision to begin studies in experimental psychology was possibly influenced by the fact that, while in the Indian subcontinent, he documented himself on this discipline in his spare time.

At that time, British psychology was characterized as a branch of philosophy. That is why Charles Spearman preferred to go abroad, specifically to Leipzig, Germany, in order to study experimental psychology, which had a certain independence with respect to the field of philosophy.

Spearman had the opportunity to receive knowledge from Wundt himself, but he did not share Wundt's taste for focusing on basic psychological processes, both cognitive and perceptual, and the Briton had a predilection for more complex situations that occur in real life, such as, for example, school performance.

After spending two years studying psychology at the University of Leipzig, he was called up to serve Britain in the Second Boer War (1899-1902). He returned from the conflict, finally graduating in psychology in 1907.

Publications and fame

Spearman's popularity is mainly due to the publication of two articles in the American Journal of Psychology in 1904, when he was still studying psychology. To this day, these two articles continue to have an impact, carrying more than 2,000 citations each.

The first, 'The proof and measurement of association between two things', sought to expand on Galton's idea of the correlation coefficient.

Spearman, despite considering the findings made by Galton and other notable researchers such as Pearson and Bravais as important, did not consider them as useful for the field of experimental psychology, believing that they should be reformulated and adapted to the demands of the discipline.

In the same article, Spearman introduces the concept of partial correlationas a way of controlling extraneous variables.

In the other article, 'general intelligence, objectively determined and measured', Charles Spearman criticizes previous experimental research, as well as trying to demonstrate the strength of the correlation coefficient.

He read about previous studies that had failed to find correlations, and pointed to possible methodological flaws, along with lack of motivation of the participants and errors in measuring and analyzing the results.

Influence on psychology

Following the publication of the two papers mentioned above, Spearman was offered a position at University College London to take charge of the experimental psychology program at that university, in addition to working as a lecturer at the institution.

This was the seed for the emergence of what was called 'the London school of individual differences', in which the likes of Raymond Cattell, Hans Eysenck and Cyril Burt, among others, were members for some 30 years. Spearman and his students continued to address human intelligence and its nature, publishing 'The Abilities of Man' in 1927.

Spearman's two major contributions to psychology, particularly in the area of the study of intelligence and the use of statistics in psychological research, are explained in more detail below.

Theory of intelligence

Spearman expounded his bifactor theory of intelligence, according to which the performance of any mental activity depends on two distinct factors.

First, there is the general or 'g' factor, which is the common basis of intelligence. and that, although it varies from individual to individual, it remains stable in the individual for any given situation.

Secondly, there are the specific factors or 's', which are all the specific capacities, which not only show themselves differently between individuals, but also vary between capacities of the same person.

Thus, according to the view of intelligence proposed by Spearman, this construct is understood in such a way that there is a general factor that is stable in the person and a series of specific factors, which are independent of each other.which are independent of each other, and which manifest themselves in the form of varied aptitudinal strengths and weaknesses.

Spearman's proposal left no one indifferent, besides being one of the first investigations in which he applied factor analysis and contributed the correlation coefficient that bears his surname.

In 1938, Thurstone criticized Spearman's observations, since he defended the idea of the existence of multiple intelligences or intellectual aptitudes, which occurred in various forms.

This author initially asserted that there were at least seven: numerical, reasoning, spatial, perceptual, memory, verbal fluency and verbal comprehension.

Later, Thurstone himself agreed with Spearman in relation to the existence of a general factor among the measures of the abilities. Years later, in 1963, Cattell also supported Spearman's ideas, but with changes in defining the factors behind intelligence.

Cattell proposed the existence of two types of factors, which are differentiated according to age: fluid intelligence, more or less similar to Spearman's 'g' factor, and crystallized intelligence, more related to knowledge in a more cultural sense of the word.

Today there is still debate as to whether or not there are different qualities in terms of intelligence, although the majority position is that there are.

Spearman's great contribution, the existence of at least one factor present in all actions in which the use of intelligence is required, is still considered one of the great discoveries in experimental psychology.

Factor analysis and Spearman's correlation coefficient

Factor analysis is a statistical method used to find relationships between multiple measures considered correlated. Spearman contributed significantly to the refinement of this method. It was he who coined the term factor analysis and used it in the measurement of multiple cognitive aspects.

In fact, It was the results obtained through factor analysis that allowed Spearman to postulate the concepts of general factor and specific factor..

Spearman applied mathematical procedures while conducting his research in experimental psychology, trying to describe and explore psychological phenomena from a statistical perspective, something that has come to significantly influence the discipline of the mind and behavior to the present day.

Spearman's correlation coefficient allows correlating two variables by ranks instead of measuring their performance separately.

Bibliographical references:

• Spearman, C. (1904a). "General Intelligence," objectively determined and measured. American Journal of Psychology, 15(2), 201-292.
• Spearman, C. (1904b). The proof and measurement of association between two things. The American Journal of Psychology, 15(1), 72-101.
• Spearman, C. (1927). The abilities of man. Oxford England: Macmillan.