General intelligence, also known as the G factor, indicates the presence of a broad mental capacity that affects performance on measures of cognitive ability. Charles Spearman first described the existence of general intelligence in 1904. According to Spearman, this g factor was responsible for overall performance in mental aptitude tests. Spearman noted that although people in certain areas perform absolutely and often excellently, people who do well in one area tend to do well in other areas as well. For example, someone who passes an oral test is likely to do well in other tests.
 
Those who hold this view believe that intelligence can be measured and expressed with a single number, such as the IQ (intelligence level) score. This foundation is that general intelligence affects performance in all cognitive tasks.
 
General intelligence can be compared to athletics. A person can be a highly skilled runner, but that doesn’t necessarily mean they will be an excellent figure skater. However, since this person is athletic and fit, he will likely perform better on other physical tasks than a person who is less coordinated and more sedentary.
 
 
Spearmen and General Intelligence
 
Charles Spearman was one of the researchers who helped develop a statistical technique known as factor analysis. Factor analysis provides researchers with a variety of test items with which they can measure common abilities. For example, researchers may find that people who score well on questions that measure vocabulary perform better on questions related to reading comprehension.
 
Spearman believed that general intelligence represented an intelligence factor underlying certain mental abilities. All tasks related to intelligence tests, whether related to verbal or mathematical abilities, were affected by this underlying day factor.
 
Many modern intelligence tests, including Stanford-Binet, measure some cognitive factors thought to constitute general intelligence. These include visual-spatial processing, quantitative reasoning, information, reasoning, and working memory.
• Visual-spatial processing includes capabilities such as putting puzzles together and copying complex shapes.
 
Quantitative reasoning involves the capacity to solve problems involving numbers.
 
• Knowledge includes a person’s understanding of a wide range of topics.
 
• Fluid reasoning includes the ability to think flexibly and solve problems.
 
• Jobs include memory, short-term memory usage, such as being able to repeat a list of items.
 
 
The Challenges of General Intelligence Concept
 
The idea that intelligence can be measured and summed up by a single number in an IQ test was controversial during Spearman’s time and has been going on for decades since. L.L. Some psychologists, including Thurstone, rejected the concept of the g factor. Thurstone instead described a series of what he called “primary mental abilities.”
 
More recently, psychologists such as Howard Gardner have opposed the idea that a single general intelligence will correctly possess all human mental abilities. Gardner suggested instead that different multiple intelligences exist. Each intelligence, such as visual-spatial intelligence, verbal-linguistic intelligence, and logical-mathematical intelligence, represents abilities in a particular field.
 
Research conducted today points to an underlying mental ability that contributes to performance in many cognitive tasks. IQ scores designed to measure this general intelligence are also thought to affect an individual’s overall success in life. However, while IQ can play a role in academic and life success, other factors such as childhood experiences, educational experiences, socioeconomic status, motivation, maturity and personality also play an important role in determining overall success.