IQ tests, or intelligence quotient tests, are assessments designed to assess human intelligence, the ability to acquire and apply knowledge. The score is derived from a series of standardized subtests. They can be a useful piece of the puzzle in diagnosing learning disabilities or identifying giftedness. Typically a score of 100 indicates average intelligence, where most people fall with a 15 +/- deviation, and a score of 130 indicates extreme intelligence, whereas intellectually disabled children receive scores of between 55 to 70.

Some research shows that IQ appears to be hereditary with environmental factors (i.e. rearing) also playing a role in intelligence. Income and IQ appear to be only somewhat correlated. Importantly, knowledge and IQ are also not equivalent. Knowledge can be acquired through sustained learning, whereas intelligence is innate. Knowledge is dynamic, changing over time and fixed to memory, whereas people of high intelligence may have a poor memory. One cannot increase intelligence with practice, whereas knowledge can be improved, although it can also be argued that the ability to acquire knowledge depends on intelligence. Applied knowledge helps individuals identify problems. Applied intelligence helps individuals solve problems.

The G score, or general intelligence, is responsible for one’s overall performance on cognitive ability assessments. The idea is that general intelligence underlies and influences performance on all cognitive tasks. For example, an athlete who is skilled at hockey would not necessarily excel at gymnastics, but because this individual is fit and athletic, they would likely perform better on other athletic tasks than individuals who are more sedentary and uncoordinated.

Two of the most widely used IQ tests include Wechsler Intelligence Scales (WISC for children and WAIS for adults) and Stanford-Binet. IQ tests measure verbal comprehension, perceptual reasoning, working memory and processing speed. They do not measure knowledge, creativity, curiosity, or emotional intelligence. These are standardised and normed tests, approved by professional psychologists’ associations. They are administered by licensed psychologists.

But why do we test intelligence? A score simplifies communication amongst professionals and provides significant information about an individual’s ability to acquire and apply knowledge. But, an individual’s results can tell us much more than this! Looking at a person’s scores on the tests’ subscales can be extremely helpful when wanting to identify a person’s strengths and weaknesses. . For example, identifying one’s strength, let’s say in visual memory, can help a student overcome their difficulties in mathematics. Thus, an intelligence test is not simply about a number but rather about the information it gives us in each area of intelligence, facilitating targeted treatment.