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Francis Galton's theory of intelligence

Francis Galton's theory of intelligence

March 10, 2024

The study of individual differences, which today occupies one of the most important areas of psychology, has its roots in the theory of the intelligence of Francis Galton .

This researcher, in addition to being a pioneer in several branches of science (including meteorology), designed some of the first tools for measuring intellectual abilities, which allowed him to reach interesting conclusions about human intelligence and its relationship with the inherited characteristics.

Who was Francis Galton?

Galton was born in England in 1822 in a wealthy family, which allowed him to be surrounded by an intellectually active environment. He was a cousin of Charles Darwin, who decades later would lay the foundations of biology by refuting creationism and Lamarck's theory of the evolution of species.


Darwin was a great influence for Francis Galton , and partly because of that, he was interested in responding to one of the great questions of psychology: are we who we are because of what we have learned or because of what we have inherited in an innate way through our parents? Galton's theory of intelligence was intended to give an answer to a part of this question: that which refers to our mental abilities when it comes to solving problems.

The basics of Galton's theory of intelligence

In the era in which Francis Galton lived, it was only beginning to be understood that life forms contain a series of genes that shape them, since Gregor Mendel, the researcher who initiated studies in genetics, was also born in 1822. However, it was already intuited that, in some way, the characteristics of the parents, or at least a part of them, pass to their offspring, forming the basic features of their biology.


On the other hand, it was understood that education and the influence of the environment have an impact on who we are and how we behave, and that this incidence already has an effect in our first weeks of life, being confused with the first forms of expression of our genes.

Francis Galton counted on the fact that both inheritance and learning are mixed when it comes to shaping not only our physical characteristics but also the psychological ones, but I wanted to know which of the two elements explained a greater part of the variance in the human population in general. For that he used tools that began to be widely used in the nineteenth century, partly thanks to him: statistics and tools for measuring psychological characteristics.

Studying the intellect

Galton designed a series of questionnaires to measure the features and characteristics of population groups that he considered relevant, seeing that people with a better social and economic position tended to give greater signs of intelligence than the rest . These studies also allowed him to see that intelligence, like physical characteristics, is expressed statistically by a normal distribution: the vast majority of people had an intelligence level very close to the average, while people with extreme values ​​( because of their very low or very high intelligence) there are always clear minorities.


Seeing that statistics could be very useful to know the mental characteristics of our species and the way in which individual differences are expressed in it, he decided to use it to verify the validity of his hypotheses about intelligence. I had come to the conclusion that the smartest people were a minority and that this coincided with the wealthiest minority, but ... was this a sign that expensive education favored the development of great intellects, or is the biological heritage of rich families tends to generate intelligent individuals?

Nature versus learning: twins studies

To answer the previous question, Francis Galton decided to look for cases in which the influence of innate inheritance could be ruled out , which would allow to see the effects of learning. That is, he resorted to the study of monozygotic twins. Studying the differences in mental characteristics of these twins over several years, he observed something curious: they could be very different or very similar, but this pattern rarely changed over time. That is to say, the twins who were very similar at birth continued to look a lot years later, and those who were very different from their early years continued to be so in later stages.

This discovery made Francis Galton, even recognizing the influence of learning and environment on the individual, end up giving more importance to the innate and the inheritance received by fathers and mothers: in the end, the effects of a constantly changing environment did not seem to be very significant in the psychological traits of the twins , that stayed more or less the same with the passage of time.

Galton and eugenics

This idea was also reflected in the theory of intelligence of Francis Galton, who understood the intellect as a tool more created by evolution and the selection of the best adapted individuals. As the most intelligent people had a greater capacity to adapt to novel situations, this was a great evolutionary advantage that needed to be enhanced. Unfortunately, as Francis Galton adopted an innate position, this meant that for this researcher the eugenics, or the selection of individuals with better innate traits It was a politically and socially useful measure.

Of course, unlike the plans of "racial cleansing" embraced by the Nazis decades later, Galton advocated positive eugenics: giving benefits to the population with better biological legacy, instead of putting barriers to the rest of the population. In practice, however, positive eugenics continued to be a clearly discriminatory proposal, which meant support for the supremacist movements that were already brewing.

Bibliographic references:

  • Pueyo, Andrés. (2013). Psychology of individual differences (in Catalan). Barcelona: University bookstore of Barcelona.
  • Sternberg, R. J .; Salter, W. (1982). Handbook of human intelligence. Cambridge, UK: Cambridge University Press. ISBN 0-521-29687-0OCLC11226466.
  • Triglia, Adrián; Regader, Bertrand; García-Allen, Jonathan. (2018). What is intelligence? From IQ to multiple intelligences. EMSE Publishing.

Francis Galton: Intelligence & Eugenics (March 2024).


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