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 various branches of science (including meteorology), designed some of the first tools for measuring intellectual capacity, which allowed him to draw interesting conclusions about human intelligence. and its relation to inherited characteristics.
Who was Francis Galton?
Galton was born in England in 1822 to 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 had a great influence on Francis Galton, And in part why he was interested in answering one of the great questions of psychology: are we who we are by what we have learned or by what we inherently inherited from our parents? Galton’s theory of intelligence was intended to provide an answer to part of this question: what does this have to do with our mental problem-solving abilities?
The foundations of Galton’s theory of intelligence
By the time Francis Galton lived, it was only just beginning to be understood that life forms contain a number of genes that shape them, as Gregor Mendel, the researcher who began his studies in genetics, was also born. have already had the intuition that in some way the characteristics of the parents, or at least part of them, are passed on to their offspring, forming the basic characteristics of their biology.
On another side, 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 relied on the fact that inheritance and learning intermingle when it comes to shaping not only our physical but psychological characteristics as well, but he wanted to know which of the two most explained the variance of the human population in general. That is why he used tools that began to be widely used in the 19th century, in part thanks to him: statistics and tools for measuring psychological characteristics.
Studying the intellect
Galton designed a series of questionnaires to measure the traits and characteristics of the population groups he deemed relevant, because people in better social and economic position tended to show more signs of intelligence than others. These studies also allowed him to see that intelligence, like physical characteristics, is expressed statistically through a normal distribution: the vast majority of people had a level of intelligence very close to the average, while people with extreme values (for their very low or very high intelligence) are always clear minorities.
Seeing that statistics could be very useful in understanding the mental characteristics of our species and how individual differences are expressed in them, he decided to use them to test the validity of his hypotheses about intelligence. He had come to the conclusion that the smartest people were a minority and that it coincided with the wealthier minority, but … it was a sign that an expensive education promoted the development of great intellectuals, or does the biological inheritance of rich families tend to generate intelligent individuals .
Nature versus learning: twin studies
To answer the above question, Francis Galton decide to look for cases in which the influence of innate inheritance could be excluded, Which would allow you to see the effects of learning. In other words, he resorted to the study of monozygotic twins. While studying the differences in the mental characteristics of these twins over several years, he observed a curious thing: They could be very different or very similar, but this pattern rarely changed over time. That is, twins who were very similar at birth were still similar – many years later, and those who were very different in their early years remained so in later stages.
This discovery made that Francis Galton, while recognizing the influence of learning and the environment on the individual, ended up giving more importance to the innate and the inheritance received by the parents: in the end, The effects of a constantly changing environment did not seem very significant in the psychological traits of the twins., Which has 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 the intellect as a tool created more by evolution and the selection of better suited individuals. As smarter people had a greater ability to adapt to new situations, this was a great evolutionary advantage that needed to be improved. Unfortunately, while Francis Galton has taken an innate positionThis meant that for this researcher eugenics, or the selection of individuals with better innate traitsIt was a politically and socially useful measure.
That said, unlike the “racial cleansing” plans adopted by the Nazis decades later, Galton advocated positive eugenics: giving benefits to the people with the best biological heritage, rather than putting up barriers for the rest of the world. population. In practice, however, positive eugenics remained a clearly discriminatory proposition, which supported the already emerging supremacist movements.
- Pueyo, Andreu. (2013). Psychology of individual differences (in Catalan). Barcelona: University Library of Barcelona.
- Sternberg, RJ; Salter, W. (1982). Manual of human intelligence. Cambridge, UK: Cambridge University Press. ISBN 0-521-29687-0OCLC11226466.
- Triglia, Adrián; Regader, Bertrand; Garcia-Allen, Jonathan. (2018). What is intelligence? From CI to multiple intelligences. EMSE publication.