Is intelligence only a single aspect or are there many facets to it? Throughout the years, there is an ongoing and lively discussion about this particular topic within the scientific community. Charles Spearman, a British scientist, proposed that there is a dominant general intelligence factor known as the G factor governing all the different cognitive abilities.
What is General Intelligence?
General intelligence is considered to be an existence of mental capacity influencing the performance on a cognitive level. As mentioned earlier, Charles Spearman was the one who postulated general intelligence in 1904. General intelligence is sometimes referred to as g factor although it can also be simply called intelligence.
According to Spearman, while each person excels in specific areas, it is still possible for them to do well in other areas. The truth is that it is actually more common for a person specializing in particular areas to excel in other relevant areas. For example, a person who excels in verbal tests will likely be able to ace other tests as well.
The same thing applies for athletes. There is no assurance that an outstanding football player will equally excel in snowboarding. But, a good football player is athletic and fit and this increases his chances to perform physical tasks better than those who don’t have the same physical coordination.
The fundamental concept here is that general intelligence or g factor has an influence on performance on different cognitive tasks. Psychometric tests are used to measure the g factor. IQ tests are the most commonly used and considered to be the most accurate measure of intelligence.
Improvements in the different analytical techniques and accumulation of data on cognitive testing were able to preserve the central role of g intelligence and paved the way to its modern conception.

Aside from introducing the concept of general intelligence, Spearman also played a role in the development of factor analysis, a form of statistical technique. This method involves the use of different test items for measuring common abilities. For example, a person who performs well during reading comprehension tests can also have exemplary performance during verbal tests.
This means that a person’s general intelligence influences all the tasks included in intelligent tests. Modern tests for intelligence such as Stanford-Binet are believed to measure different cognitive factors making up general intelligence. These tests include the following:
- Test involving the ability to solve numerical problems
- Quantitative reasoning
- Flexible thinking for solving problems
- Fluid reasoning
- Knowledge
- Ability to copy complex shapes and put puzzles together
- Visual-spatial processing
- Working memory
- Knowledge of a person about various topics
- Short term memory capacity like list repetition
Critical Evaluation of the G Factor
The idea of intelligence measurement with one number based on an IQ test remains controversial to this day. This is the reason why a lot of psychologists ridicule the g factor concept.
A renowned psychologist, Howard Gardner, suggested a multiple intelligence theory as opposed to the General Intelligence theory of Spearman. The intelligences of Gardner are composed of abilities in different domains like spatial intelligence, logical mathematical intelligence, and others.