Is Intelligence Fixed or Malleable?

As the world pushed through the nineteenth century and entered the twentieth, humankind experienced massive transformations in social, economic, political, cultural, and academic arenas. Although the late 1800’s were a tumultuous time, we did emerge on the other side with amazing advancements in all sorts of areas. One such advancement was the development of the concept of intelligence. Before the late 1850’s, people only maintained a vague idea of what being ‘intelligent’ actually meant. Through the work of intelligence theorists such as Francis Galton, Alred Binet, and Charles Spearman, however, humankind gained a much clearer concept of this abstract phenomenon. The three aforementioned intelligence theorists clarified our definition of intelligence by leaps and bounds, but yet fierce controversy lingers today over the concept. One can understand the nature of this controversy and how the debate over intelligence came into existence by studying the similarities and differences of Galton, Binet, and Spearman.


**Alfred Binet; circa 1904

To understand intelligence, we must first examine a basic scientific and psychological dichotomy: “nature versus nurture.” People toss around this phrase often in debates on intelligence, but what does it actually mean? Francis Galton was allegedly the first to coin the phrase, and it describes the struggle to assign responsibility for particular traits (physical, social, intellectual, etc.) to one’s genetic makeup (nature) or the environment in which one grew up (nurture). Today, there seems to be a bit more of a consensus that nature and nurture interact to produce the people that we become, but back in the early days of intelligence theory, there was no such concession.

I would argue that perhaps the most fundamental divider among intelligence theorists is their view on whether or not humans can change their level of intelligence. This boils down to the nature versus nurture debate. Those who support nature as the stronger influence view intelligence as a fixed, inherited entity. Those who support the nurture side of the argument view intelligence as malleable, or subject to change depending on one’s environment.

Now, let’s take a look at the pioneers of intelligence theory and with which side of the debate their views align. Francis Galton was of the nature camp of the debate. In his book “Hereditary Genius” (1869), Galton “assembled long lists of “eminent” men—judges, poets, scientists, even oarsmen and wrestlers—to show that excellence ran in families” (Holt, Jim). **Read more of the article on Francis Galton’s work here.** The counterargument is that the children of these excellent men could have become excellent because they had grown up in exceptional households. Galton countered this argument with a control group in his experiment of adopted sons of Popes who were still “eminent.”


**Francis Galton; circa 1890

Charles Spearman was in agreement with Galton in that he, too, was a proponent of a fixed view of intelligence. Spearman based his belief off of positive correlations among students’ performances on specific subject tests (such as Latin and Music). He saw that those who did well on one test tended to score higher in general than those who did poorly. This led him to believe that there is a force that underlies all intellectual tasks. Spearman went on to create the concept of “g:” a mental energy that underlies all intellectual tasks. “G” is a fixed mental energy that education, therapy, and training cannot alter. (Howard Gardner, Mindy Kornhaber, and Warren Wake, pg. 58-70)

spearman correlation

**An example of positive correlation for high scores on one test and high scores on another. Read more on the role that correlational research has played in the development in Stephen Jay Gould’s book Mismeasure of Man. For a summary, try looking here.

Alfred Binet, on the other hand, belonged to the nurture side of the argument. In 1904, the French government asked Binet to assist them in organizing their education system to accommodate for the recent switch into mass education. Binet obliged and he and a colleague, Théodore Simon, created mental tests to determine which students were capable of regular schooling and which were not. Binet desired an understanding of how intelligence works so that society could make sound, informed decisions in regards to education. He believed that society could improve the mental capabilities of populations through these decisions. Although Binet’s work eventually led to quantifying people’s intelligence (and what would later turn into Intelligence Quotients, or IQ scores), he did not see this score as fixed. He believed that this number could be changed if a child was placed in the correct environment.

2 thoughts on “Is Intelligence Fixed or Malleable?

  1. Cara Dore Post author

    @kma5477: The different abilities you mentioned (understand concepts of the world, calculate equations) are both examples of crystallized intelligence. Binet’s original test measured this form of knowledge, which boils down to what facts you know. Other forms of intelligence tests do not test crystallized intelligence and instead measure fluid intelligence, which is one’s ability to solve problems using their working memory space. This would be where thinking critically fits into the puzzle. Spearman tested students’ performance on various subjects, but they had all had the same level of schooling. He did this to control for the variable of having a formal education. He found that students who did well on one subject also did well on other subjects, supporting the idea that there is a mental energy (“g”) underlying those with intelligence. I agree with you, though, that some people are just naturally more inclined to do better in certain areas than others. Since the time of Galton, Binet, and Spearman, the concept of intelligence has developed much further. I will delve into “multiple-intelligence theory” in a future post which is sort of what you were describing with people being smart in different ways. Thank you for responding!! 🙂

  2. kma5477

    I would say a significant amount of intelligence is gained through nurture, as a formal education is needed to understand concepts of the world, calculate equations, and learn to think critically. Obviously a person with a proper education would perform better on a mathematics proficiency test than someone who has not been exposed or taught the material, yet I believe intelligence is also largely inherent or determined by “nature.” I have known people who study an incredulous amount and received a lower score on an exam than someone who did not study one bit. People are gifted in different areas, and it isn’t for lack of trying that one person cannot comprehend a concept that another picks up right away. I think all the time about the innovators who invented computers or the internet and how they could possibly come up with these unheard of ideas and actually create them, and no matter how much I think about how they could have accomplished these feats, I cannot fathom it. I perform well in school, but I don’t think I could ever think up anything of this caliber. I think the great inventors of the past and present possess brains that run on different wavelengths due to the genetic makeup that is unique to each person.

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