Online tests tend to give inflated scores, because if you score higher, you feel better about it, and are more likely to purchase the product the test was intended to sell. (A complete profile indicating your strengths for $15, for example).

On the other hand, Standardized IQ tests are just that: standard for the population. Careful research on thousands of people validates the results. There is also something called the Flynn effect, meaning that the population gains .3 IQ points every year. This means that test writers have to continually make the tests more difficult, in order to keep the population average at 100.

Getting an IQ of 100 makes you totally NORMAL, not “dumber”. Most people, as you know, score between 80 and 120, with the majority of scores clustered at the 95-105 range. So most of the people you know have “average” IQs.

Now, regarding the IQ score of 130: Only 2.5 % of the population have an IQ score that high. It is highly unlikely that you suddenly lost 30 points in a couple of years. Chances are your IQ is closer to 100 and the 130 score was inflated. However, if the 130 score was from a legit professionally administered test and you are now horrified that you only scored 100, take a REAL test again in a year. Make sure that you’ve spent the year reading, learning, and stimulating your brain, eating right and getting rest. Chances are, if you’re indeed a clever person, you’ll get a better score under those circumstances.

To get a reliable IQ, the testing must be done under test conditions. The biggie is the testing is done individually.

The following website has great info:

http://www.wilderdom.com/intelligence/IQWhatScoresMean.html