Everyone’s heard of IQ, but most people don’t really understand what it means. An IQ score is usually thought to be an objective measure of how smart a person is. Many people don’t know that this number is actually an average of scores on about 10 different tests measuring different skills. These skills are thought to collectively measure a person’s intellectual abilities. When the scores are fairly close together, the average is a meaningful number and can give a reasonable estimate of the person’s intellectual abilities.
However, when these scores are variable, the average is an essentially meaningless number which masks a lot of potentially useful information. For example, an IQ score of 100 could mean that all of a person’s abilities are average. It could also mean that they have very strong verbal abilities and very weak nonverbal abilities. These two options would lead one in very different directions. When the person’s performance on an IQ test is variable, it is much more accurate and helpful to look at the scores as a profile of strengths and weaknesses.
It is also important to know that IQ scores are influenced by many things in addition to the person’s intellectual abilities. For example, difficulty expressing your ideas in words, attention problems, slowed processing speed, anxiety, depression, and fatigue can all have a negative impact on IQ scores.
IQ tests are essentially a collection of different kinds of problems people are asked to solve. A skilled neuropsychologist will look not only at the scores, but also at the process by which the person goes about solving these problems and the types of errors they make along the way. This type of analysis provides a wealth of information about how a person thinks, how they solve problems, and how their mind works.