IQ Tests

What Do My Scores Mean?

When you take any of our tests, you will receive 3 scores:

Raw Score - The number of problems you answered correctly.

Percentile - The estimated percentage of adults in the general U.S. population who would have achieved a score equal to or below the score that you achieved.

IQ - IQ scores are tied directly to your percentile ranking with respect to the general population. The IQ scores we give are based on a 15 point per standard deviation scale (used for the Weschler intelligence tests and the most recent Stanford-Binet test). A nice chart that shows which IQ scores match with percentiles can be found on http://www.iqcomparisonsite.com/IQtable.aspx - this chart also shows IQs on a 16 point standard deviation scale (used for many of the older Stanford-Binet tests).

What Do IQ Scores Mean?

For some time this has been hotly debated. For any test, an IQ score of 100 is average (the 50th percentile, right in the middle of the population, with half of the population scoring above this level, and half below it), so anything below that is at least slightly below average, and anything above it at least slightly above average (IQ 90 has been called "low normal" and IQ 110 "high normal" for some tests). An IQ score of 130 indicates a 98th percentile ranking (the top 2 percent) on the scale we use, which has often been the minimum to be classified as "gifted", and is the minimum to join Mensa and some other organizations (however, most tests on the internet, including ours, cannot be used to join any of these organizations). To learn more about the meaning of actual clinical IQ scores of the type you'll achieve from tests given by psychologists and other professionals, there are many other sites that deal with this issue better than we can. You might try doing searches in the search box below using terms such as "mental age IQ", "cultural bias IQ", "nature vs. nurture IQ", "environment and IQ", "gifted children", "intelligence testing" and others:

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Books and other resources also deal very well with these subjects:

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Our tests are for entertainment purposes only. Having said that, your percentile ranking and corresponding IQ should give you an idea of how you rate compared to others in a number of areas, including logical thinking, mathematical skills, verbal ability, and visual/spatial reasoning. IQ scores and scores on various aptitude tests correlate highly with success in school, work, business, and other areas. Brighter people tend to be more successful.

Can IQ Be Increased?

This is again a debated topic. Some say not at all, others that it can be slightly, and some say that it can be increased significantly. You can to some extent test this yourself by taking several of our tests over time. If you create a free account, you can have your scores recorded for all of our tests that you take. You can easily chart your progress over time, and also see where your strengths and weaknesses might lie.

Sample Sizes, Raw Scores, and Our Norm Tables

The percentile and IQ scores that we give you on our tests are based on all of the people who have taken our tests. If only a few hundred or even a few thousand people have taken a test, the score you receive may not be very accurate, especially if you did extremely well on the test. As more people take the tests, and we have tens of thousands, hundreds of thousands, and eventually millions of submissions on particular tests, the scores that you receive will be more accurate. The Norm Tables that we maintain for the tests are adjusted every 24 hours to reflect the new data that we receive, and if you create a free account and login before taking each test, your percentile and IQ scores will be adjusted as well. While the raw scores that you achieve will not change, the percentile and IQ scores that they correspond to likely will, as more and more data is accumulated.

Test Population vs. General Population

The population of people who take our tests is almost certainly skewed in comparison to the general U.S. population. The people taking our tests are typically much brighter than average compared to the general public. We make some adjustments in our scoring to compensate for this; however, our methods are very conservative compared to most of the sites on the internet, which too often assign exaggerated scores.