Some behaviorists, beginning with Charles Spearman (1863 – 1945), posit each person has a certain degree of intellectual ability called a g factor, or just g, standing for general intelligence or general mental ability. They observe that people who have higher achievement in one academic subject (such as language or math), tend to have higher achievement in multiple academic subjects, and people who have lower achievement in one academic subject, tend to have lower achievement in multiple academic subjects. Many believe the g factor accounts for this high correlation, that each person is born with a certain amount of g, and that this amount does not change throughout a person’s life. Even if this theory is true, attempts to measure a person's g as a single number have been less than perfect.

 

Alfred Binet (1857 – 1911) developed the first test designed to measure intelligence in children. Later, Henry Goddard (1866 – 1957) introduced the concept of an Intelligence Quotient, or IQ. He took the mental age of a child and divided it by that child's physical age and then multiplied by 100 to establish an IQ. A child whose mental age and physical age are identical has an IQ of 100. An IQ above 100 supposedly indicates a child's mental age is above that child's physical age, or the child has above average intelligence, and an IQ below 100 supposedly indicates a child's mental age is below that child's physical age, or the child has below average intelligence.

 

Modern IQ tests have a mean of 100 and a standard deviation of 15. About 95 percent of the population should score between 70 and 130 with scores above 130 indicating exceptional intellectual ability and scores below 70 indicating intellectual challenges.

 

When used as they were originally intended, tests designed to measure intelligence identify children who might benefit from special programs specifically structured to their abilities with a goal of increasing their success. Unfortunately, IQ tests, and, later, aptitude tests (such as the ACT, the SAT, and the GRE) have been used in inappropriate ways to disparage groups of people and to exclude individuals from school programs and other potentially advantageous opportunities. Although research suggests it is better to use multiple measures to determine placement, many institutions of higher learning find it more expedient to use a single test score to determine, for example, which math class a potential student should take.

 

Research demonstrates most IQ tests and aptitude tests are biased in favor of middle-class test-takers and biased against people of color and women. Additionally, as Christopher Shea reported in the October 29, 2012 issue of the Chronicle of Higher Education, James R. Flynn identifies a few problems with current IQ tests. For one thing, the tests indicate people are getting significantly smarter over time, which other measures do not confirm.

 

While we now know most of the tests are biased against people of color, Robert Yerkes (1876 – 1956) used differences in performances on an army intelligence test to justify racist policies. Some people have tried to use similar differences to justify eugenics.

 

Other people present alternatives to the idea of a single g factor, such as Howard Gardner's theory of Multiple Intelligences. The theory of Multiple Intelligences posits there are several ways for people to be smart. Children who excel at one of these intelligences often excel at others as well, but sometimes a child who is typically average is outstanding at one particular type of intelligence. This idea is appealing to many teachers, but, according to a Youtube video called “Theories of Intelligence” posted by Khan Academy, as yet has little or no data to support it.

 

You can view the video here:

 

Of the original seven of the Multiple Intelligences suggested by Howard Gardner, most are correlated with g, meaning that people who test for a high g factor also test high for, say, Intrapersonal Intelligence. Bodily-Kinesthetic Intelligence is the least correlated with g. Visual-Spatial Intelligence is the second least correlated with g.

 

 

Other Resources:

 

https://www.verywellmind.com/what-is-general-intelligence-2795210

 

https://en.wikipedia.org/wiki/G_factor_(psychometrics)

 

https://www.verywellmind.com/gardners-theory-of-multiple-intelligences-2795161

 

 

References:

 

Bartlett, T. (2011, December 21). Is intelligence in the genes? Chronicle of Higher Education

 

Carter, P. J. (2007). IQ and psychometric tests: Assess your personality, aptitude, and intelligence, 2nd edition.

 

Shea, C. (2012, October 29). IQ wars continue with battles over new puzzles. Chronicle of Higher Education.

 

Visser, Beth A., Ashton, Michael C., and Vernon, Philip A. (2006). “g” and the Measure of Multiple Intelligences: A Response to Gardner. Intelligence, 34(5) 507-510.