The ancient Greeks believed that the soul resided in the brain while the seat of the intellect was found in the chest, near to the lungs. Nowadays we know that the brain is in fact responsible for thought and intellect. Brain scanning technology has found that a part of the brain called the lateral pre-frontal cortex has an increase in blood flow when people perform problem solving tasks. The concept of tests to measure intelligence was first proposed about 100 years ago.
History of Intelligence TestingTests of mental ability were first used as part of an effort to identify children of low intelligence who were likely to have difficulties in school. Psychologists designed tests to check practical knowledge, memory, reasoning, vocabulary and problem solving. They were similar to today's tests in their general principles, involving performance of simple commands, repetition of spoken numbers, naming of objects in pictures, definitions of common words and abstract terms and telling how two objects are different.
Nowadays, IQ tests are actually used more commonly for adults than for children.
Modern IQ TestsModern tests aim to measure verbal, mathematical and spatial ability, memory and reasoning. They are pre-tested on a group representative of the larger population, then graded so most people get 90-110.
- Under 70: mentally retarded (2.2%)
- 70-80: borderline retarded (6.7%)
- 80-90: low average (16.1%)
- 90-110: average (50%)
- 110-120: high average (16.1%)
- 120-130: superior (6.7%)
- Over 130: very superior (2.2)
Indeed the question of defining intelligence is contentious, even within Western society and amongst psychologists. Between different societies, the differences in world view are even more pronounced. In the West, we associate verbal and mathematical skills with intelligence, but other cultures disagree. Seafarers of the South Pacific view spatial memory and navigational skills as markers of intelligence.
What's the Use of IQ Tests?Some researchers think IQ tests assess problem solving ability rather than general intelligence. Others argue that they assess only analytical and verbal aptitude and miss out creativity, practical knowledge and skills needed to solve real world problems. Maybe they only show how good someone is at doing IQ tests!
Whether or not they really test intelligence, IQ test results certainly have some unarguable implications. Social statistics related to IQ show definite trends. As a group, people with lower IQs are far more likely to be unemployed, live in poverty, go to prison, drop out of school and get divorced than are people with high IQs. Individuals with high IQs tend to succeed academically, get better jobs and earn more money.
Yet starting life with an enormous IQ is no guarantee of future success. Lewis Terman, one of the founders of IQ testing followed children with "genius" IQs of over 140, expecting that they would become leaders of their generation. While many of these children, ( who jokingly called themselves "termites") did go on to excel, many seemed to flounder on reaching adulthood, not managing to hold down jobs, or merely performing to mediocre standards at their jobs. Several became alcoholics and some committed suicide. Other factors than IQ alone are clearly critical in determining the course of individual success or failure.
Who Uses IQ TestsDespite the controversy and lack of clarity about exactly what IQ tests mean, they are widely used nowadays. Many countries use forms of testing known as "psychometric" to determine university admissions, for example the American SAT tests. This hasn't caught on yet in the UK, but many companies use similar testing to check the ability of potential employees, as does the government, the civil service and the armed forces.
Testament to the popularity of IQ tests and their ilk are the plethora of websites offering free IQ tests. (Though you usually have to pay for analysis and explanation of your results.) On a more frivolous note, there are even "PhD certified" online tests which you can use (at a price) to assess every conceivable aspect of your life, relationships, career, mind and body. Apparently IQ testing is somehow used to determine everything from whether you are a natural leader, to which hairstyle is right for you, what your past life was and which celebrity reality show suits you. There's even a "sex IQ" test. The mind boggles!