Mind Expanding Techniques

This page deepens into Theory of Intelligence. We will talk about how psychologists approached the meaning of intelligence and developed their theories. We will also see briefly some of the most important theories of intelligence.

Although, psychologists have agreed on that the key to understand intelligence is the ability of the environment adaptation, scholars still don’t agree to a single Theory of Intelligence.

There are groups of researchers that study intelligence using psychometric tests and analyzing the results. Others believe that intelligence draws upon many other abilities that are not measurable from the tests. Recently, psychologists tried to explain intelligence using a biological point of view.

Some of the most important theories of intelligence follows:

General Intelligence

In 1904 Charles Spearman proposed the first theory of intelligence. Spearman said that there is a general mental capability, symbolized with letter g, which represents Intelligence. This factor determines the performance in all intellectual tasks.

His conclusions resulted when he noticed that people who performed well on a mental-ability test, tended to do also well on other tests. In the other hand, people who performed poorly on a test also tended to perform poorly on others.

Numerous researchers based on this theory of intelligence and developed new ones. Some of them follow.

Primary Mental Abilities

In 1938 Louis L. Thurstone proposed the Primary Mental Abilities theory. That was that there are seven independent primary mental abilities which constitute the human intelligence. These are the following:

o Verbal Comprehension

o Verbal Fluency

o Number or Arithmetic Ability

o Memory

o Perceptual Speed

o Inductive Reasoning

o Spatial Visualization

Thurstone identified the above abilities after creating a set of 56 tests. His wife Thelma helped him to create this test set. Then they administered this test set to 240 college students and from the results analysis, Thurstone, developed the Primary Mental Abilities theory.

Fluid and crystallized intelligence

In 1966 Raymond B. Cattell and John Horn developed the Fluid and Crystallized intelligence theory. Intelligence consists of two major abilities, the fluid intelligence and the crystallized intelligence.

The fluid intelligence is the biological aspect of intelligence and it is measured by the speed of reasoning and memory capacity. Also, it is increased into adulthood and decreased with aging process.

The crystallized intelligence is the skill expansion ability through learning and experience. The sources of learning and experiences are unlimited so this type increases during our lifetime.

Multiple Intelligences

This theory proposed from Howard Gardner in 1983. He concluded that there are seven different types of intelligences. These are:

o Linguistic

o Musical

o Logical-Mathematical

o Spatial

o Bodily-Kinesthetic

o Intrapersonal

o Interpersonal

In late 1990s Gardner added one extra type of intelligence, the naturalist, which was the ability in recognizing plants, animals and minerals.

Gardner based his research not so much in analyzing psychometric tests, but studying strange cases, like people who had lost of a mental ability and improved another or people who excelled in a skill but not in others and people who developed their abilities in the absence of others. He concluded that there must be multiple independent intelligences that explain the strange cases that he studied.

He also identified a renowned personality, with high intellectual performance, for each intelligence type.

So in linguistic Intelligence he nominated the poet T.S Eliot, in Musical Intelligence the composer Igor Stravinsky, in Logical -Mathematical the physicist Albert Einstein, in Spatial intelligence the painter Pablo Picasso, in bodily-kinesthetic the dancer and choreographer Martha Graham, in Intrapersonal Intelligence, which is the ability to understand one’s self, the leader Mohandas Gandhi, the Interpersonal, which is the ability to understand other’s personality the psychiatrist Sigmund Freud and finally into his eighth addition, the naturalist, he identified the naturalist Charles Darwin.

Triarchic Theory of Intelligence

In 1985 Robert Sternberg formed the Triarchic Theory of Intelligence. Sternberg said that intelligence is divided to three major skills which follow.

o Analytic intelligence

o Creative intelligence

o Practical intelligence

The main difference of the Triarchic Theory of Intelligence from the previous theory of multiple intelligences, is that in Sternberg’s theory the three parts are related each other and are divisions of a bigger entity.

The analytic skill draws on the basic cognitive processes. It is the ability to reason, to process information and to solve problems. Also it’s the skill that resembles more with the general concept of intelligence.

The Creative Skill is the ability to use past experiences and learn from them in order to deal with new situations in the future.

Sternberg noticed that the psychometric tests were unable to measure the creative intelligence because people who had scored high in such tests, had problems in dealing in real life situations.

The practical skill is the people’s adaptation ability to environment. This is like the recent definition of intelligence.

People, who are able to adapt to and manipulate their environment in order to bring it on their needs, have a tendency to be successful in real world situations. Sternberg also noted that high practical intelligence does not mean high scores on IQ tests.

Biological Research of Intelligence

The Psychometric theories approach intelligence based on hypothetical mental constructs. Biological studies are not based on such hypothesis.

Followers of these theories, also called reductionists, believe that the way to understand intelligence and its nature is by identifying the biological processes which underlie intelligence.

The conclusions of biology should be used together with the psychometric theories in order to construct a unique Theory of Intelligence.

Hemispheric Research

The Psychologist Jerre Levy and others found that the brain hemispheres are related to different processes. The left hemisphere is responsible for analytical thinking and problem solving while the right hemisphere handles visual and spatial tasks.

Brain wave studies

One other topic which Biologists research, is the brain wave activity. There are many studies in this field that examine the brain waves of patients that are mentally active. For example the psychologist Hans Eysenck studied the brain wave patterns in patients who were taking an intelligence test.

Many studies have proven that maybe there is a relation between EEG (Electroencephalogram) waves, ERP (Event-Related-Potential) waves and the results of intelligence tests.

Blood-flow Research

This type of biologic research is more recent and focuses on the measurement of the brain’s blood-flow. Blood-flow is a sign of brain activity. So these measurements take place in patients that are performing cognitive tasks.

Some interesting results of these studies are that patients who performed well on intelligence tests had an overall decreased blood-flow than other patients who performed less well. These conclusions resulted from psychologist Richard Haier using a Positron Emission Tomography (PET).

Also psychologist John Horn found that older adults showed a decreased blood flow in some brain areas such as areas responsible for concentration.

References

intelligence, human. (2009). Encyclopdia Britannica. Encyclopdia Britannica 2009 Student and Home Edition. Chicago: Encyclopdia Britannica.

Detterman, Douglas K. “Intelligence.” Microsoft Student 2009 [DVD]. Redmond, WA: Microsoft Corporation, 2008.

Intelligence, www.Wikipedia.org