Francis Galton’s theory of intelligence

One of the first thinkers who tried to explain the human intellect.

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

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 inherited characteristics.

Who was Francis Galton?

Galton was born in England in 1822 into a wealthy family, which allowed him to be surrounded by a very 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 on Francis Galtonpartly because of his interest in answering 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 innately from our parents? Galton's theory of intelligence sought to provide an answer to one part of this question: that which refers to our mental abilities when it comes to solving problems.

The foundations of Galton's theory of intelligence

At the time when Francis Galton lived, it was just 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, somehow, the characteristics of fathers and mothers, or at least a part of them, are passed on to their offspring, forming the basic features of their biology.

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

Francis Galton was counting on the fact that both heredity and learning are intertwined in shaping not only our physical but also our psychological characteristics, but he wanted to know which of the two elements accounted for more of the variance in the general human population. For this 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 intellect

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

Seeing that statistics could be very useful to learn about the mental characteristics of our species and the way in which individual differences are expressed in it, he decided to use it to test the validity of his hypotheses about intelligence. He had come to the conclusion that the most intelligent people were a minority and that this coincided with the better-off minority, but... was this a sign that expensive education favored the development of high intellects, or is it that the Biological inheritance of wealthy families tends to generate intelligent individuals?

Nature versus learning: the twin studies

In order to answer the above question, Francis Galton decided to look for cases in which the influence of innate inheritance could be ruled out.which would make it possible 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, twins who were very similar at birth continued to resemble each other many years later, and those who were very different from their earliest years remained so in later years.

This discovery led Francis Galton, while recognizing the influence of learning and the environment on the individual, to give more importance to the innate and to the inheritance received from fathers and mothers: after all, the effects of an environment that changes the individual's personality are not always the same.the effects of a constantly changing environment did not seem to be very significant in the psychological traits of twins, who remained more or less the same.The effects of a constantly changing environment did not seem to be very significant on the psychological traits of twins, which remained more or less the same over time.

Galton and eugenics

This idea was also embodied in Francis Galton's theory of intelligence, which understood intellect as one more tool created by evolution and the selection of the best adapted individuals. Since more intelligent people had a greater ability to adapt to novel situations, this was a great evolutionary advantage that should be enhanced. Unfortunately, since Francis Galton adopted an innatist stanceThis meant that for this researcher eugenics, or the selection of individuals with better innate traits, was a useful political and social measure.was a politically and socially useful measure.

Unlike the "racial cleansing" plans embraced by the Nazis decades later, however, Galton advocated positive eugenics: giving advantages to the population with the best biological heritage, rather than putting up barriers to the rest of the population. In practice, however, positive eugenics remained a clearly discriminatory proposal, which gave support to the supremacist movements that were already taking shape.

Bibliographical references:

• Pueyo, Andrés. (2013). Psicología de les diferencies individuals (in Catalan). Barcelona: Librería universitaria de Barcelona.
• Sternberg, R. J.; Salter, W. (1982). Handbook of human intelligence. Cambridge, UK: Cambridge University Press. ISBN 0-521-29687-0OCLC11226466.
• Triglia, Adrian; Regader, Bertrand; Garcia-Allen, Jonathan. (2018). what is intelligence? From IQ to multiple intelligences. EMSE Publishing.