IQ, or intelligence quotient, is supposed to indicate how much potential you have to be...intelligent I guess. The odd thing about IQ is that it can't really be disproved nor, realistically, does it actually indicate any real information. See, if someone has a high IQ and doesn't do well in school, we can say they either are not motivated enough or they are "just not good at taking tests." In light of the problems and restrictions associated with IQ rankings, I am going to discuss several reasons why IQ tests are less than beneficial.
First, IQ tests have a certain amount of inaccuracy built into them by their very nature. The were created by humans, and humans can only accurately evaluate subjects that fall within their scope of expertise and intelligence. For example, if you are in school and a teacher introduces a new concept, how are you to know if that concept is true or not? Simply put, there's no way you can possibly know the validity of the claim unless you can devise some method to do so. Even then, the method of evaluation you use must fall within your arena of knowledge. I have said all that to say that in the same way, intelligence can only to accurately determined for people with IQs below that of the test creator. If this is true, how can we make statements as to the IQ of Einstein? All that we could accurately determine is that he is more intelligent than a given test creator.
The second reason that IQ tests are not useful is that they only measure a specific type of intelligence. As stated above, a given evaluator will stick to subjects and ideas within their own knowledge bubble. This creates a very one-dimensional test. Even "good" IQ tests can never fully encompass the full scope of intelligence. In fact, the idea had come out recently that there are different types of intelligence. I support this theory and believe that a single test can never fully evaluate a individual's intelligence in all sectors, nor are typical IQ tests equipped to do so.
The third and most important reason that IQ tests are not incredibly useful is that they only measure potential. At the end of the day, it doesn't matter how much potential you have if you don't use it. By the same token, it doesn't matter how much potential you don't have, if you use it effectively, you can be much more than an unmotivated person with a lot of potential. This can be seen often in school. Many times the person who got straight As without studying in high school will not do as well at college as a person who struggled to get Bs in high school. See, college, believe it or not, is harder than high school and it is more important to have a good work ethic than to be incredibly gifted. Both help but work ethic is much more valuable than IQ.
To quote Will Smith in the movie Hitch, "You can't use what you don't have." He goes on to say that you have to use what you have. In the same way, it doesn't matter what IQ you have but how you use it. You can be the smartest person in the world, but if you so nothing but sit in front of the tv, it is of no benefit. After all, genius is 1% inspiration and 99% perspiration.
So what exactly do IQ tests do? For any person taking an IQ test, there are three likely results. One, they may score exactly what they suspected they would. In this event, nothing is likely to change in the individual's outlook and the test is a waste. Two, the subject might score lower than expected. This could result in either depression and less production or a desire to work harder to make up for lost ground. Third, the subject might do better than expected and be called a "genius." He will then either continue as before and the test will be a waste, or they will develop a large ego and consequently not try as hard as they should. Ironically, the only likely solution where an IQ test will do good is if the result is bad.
In the end, an IQ test is just like any other test. It is biased, far from perfect, unfair, and certainly not the end all of intelligence measures. I've said it before and I will say it again: it doesn't matter how smart or dumb you are, what you do with your intelligence is what defines you.