What Your IQ Score Really Means

Ever heard of someone classified as a "genius"? Or how about someone who has a low IQ? What is the average IQ score, anyway? And how do you calculate that score? I had a lot of these questions because I am a psychology grad student. After taking an assessment class, I found the answers to these questions and felt that people would understand themselves a little better if they knew what made up their IQ scores.

First we must understand exactly what IQ measures. IQ stands for "Intelligence Quotient." Intelligence is defined as "the aggregate or global capacity of the individual to act purposefully, to think rationally and to deal effectively with his environment," according to Encyclopedia.com. In other words your intelligence is measured according to how you adapt to your environment or culture. People who have very little formal education or speak little English can still have high IQs, whereas people with high "book smarts" can have average scores based on performance. The definition of IQ came from the psychologist David Weschler, who developed the test most people take to receive an IQ score. This test is called the Weschler Adult Intelligence Scale, or WAIS. The most current version is the WAIS III. What makes the WAIS III so reliable is that it was developed along a wide range of backgrounds, ethnicities and demographics of people in modern society. Although no intelligence test can fully measure someone's capabilities, the WAIS III is regarded as the closest, most valid of all tests.

The score you see (called the Full Scale Intelligence Quotient or FSIQ) comes from testing in two major categories: Verbal IQ and Performance IQ. Your Verbal IQ (VIQ) measures can display how well you have been educated in our society and retained that information. The tests in this category will ask questions centered on your vocabulary, solving word problems, contrasting and comparing two items, etc. A tester, for example, may ask a question like "what is the difference between a cat and a dog?" with your score depending on how you answer the question.

The Performance IQ (PIQ) measures your ability to process new information. The tests involved in calculating your PIQ involve decoding information, matching up symbols, rearranging blocks to make specific patterns, etc. For one subtest, a tester may show you a picture and ask you what is missing it.

In all there are 16 possible tests you could take, depending on your tester and special situation. For example, if you have Parkinson's disease and are shaking, you most likely will not take any tests that require hand-eye coordination. It would not an accurate display of your intelligence in that area.

After your tests are taken, your scores are divided into four different indexes: Verbal Comprehension Index and Working Memory Index for the VIQ; the Perceptual Organization Index and Processing Speed Index for the PIQ. Then, as mentioned earlier, the two scores are combined to make up your Full Scale IQ.

According to the WAIS III scale, 68% of people have FSIQ scores that fall between 80 and 100. 5% of people score below 70 which is categorized as mental retardation. "Genius" is considered when people score 140 and above, which accounts for 1 in 400 people. MENSA, an organization with high IQs, accepts members who are in the top 2% IQ scores of the population.

By understanding how the IQ score is calculated, you can truly measure someone's intelligence because sometimes people are actually lacking in certain areas or may be exceeding in certain areas. You won't be able to tell this from the surface. Let's say you find out that you have an IQ of 100, which is considered the high end of the average score in our society. In school you seemed to really understand books and classes one or two grades ahead of you but for some reason when you had a hard time taking tests with time limits.

If you scored 110 in your VIQ but your PIQ is 90, a tester may dig deeper and find out why there was a 20 point difference between the two areas. By looking into one of the PIQ indexes like the Processing Speed Index, he may see that for some reason your processing speed scored lower than all your other categories with an 80, which is right on the border of average. This could lead to several possibilities of explaining the way your mind works. Maybe you have a slight case of attention deficit disorder. It could also be possible that area in your brain never fully developed. If you were in an accident that may have caused slight head trauma, the part of your brain that was injured may have been the area that processes information as you take it in. There are numerous possibilities that just knowing that you have an FSIQ score of 100 would not be able to tell you.

So whether you believe you are smarter than the average bear or dumber than a box of rocks, I would recommend getting a WAIS III test or similar version done and take into account this information. After all, there may be a budding genius inside your brain!