In general, knowing more is better than knowing less. However, if you already believe things that are false, sometimes an additional true information makes you believe more false things. Specifically, if you (falsely) believe that certain values of IQ imply X, Y, Z, then learning your (true) IQ would make you (falsely) believe X, Y, Z about yourself.
IQ is an important trait, but there are also other important traits, and various mental conditions. People who learn about their IQ often make the mistake of trying to explain everything about themselves by their IQ, even if more likely explanations are available. (For example, it is tempting to believe things like “I have a problem connecting with people, but that’s because my IQ is higher than theirs” when it’s actually lack of social skills; or “I feel bad, because my IQ is so high that I can see many bad things in this world” when it’s actually depression.) The life outcomes also depend on environment, and luck.
On the other hand, underestimating IQ also leads to false beliefs about the world. For example, after observing that some (high-IQ) children have great results at school, while other (low-IQ) children have bad results, an IQ denialist would have to invent an alternative explanation; for example, they could believe that the former are hard-working and the latter are lazy, or that the former have some unfair advantage (other than the IQ), depending on their sympathies.
Another problem is that even if you won’t take the test, you probably already have some beliefs about your intelligence. Those may be accurate, or not. Maybe you just got [un]lucky. Maybe the feedback you got reflects the prejudice of your parents and teachers more than your actual traits. I don’t see an advantage of keeping a (potentially wrong) belief, instead of taking the test. There is nothing you can do about your IQ, so maybe it is better to focus your attention on things you can change. But taking one test should not prevent you from doing that.
With regards to rationality, both high-IQ and low-IQ people can be pretty irrational, albeit in different ways. Smart people can invent really complicated excuses for doing the wrong thing.
In general, knowing more is better than knowing less. However, if you already believe things that are false, sometimes an additional true information makes you believe more false things. Specifically, if you (falsely) believe that certain values of IQ imply X, Y, Z, then learning your (true) IQ would make you (falsely) believe X, Y, Z about yourself.
IQ is an important trait, but there are also other important traits, and various mental conditions. People who learn about their IQ often make the mistake of trying to explain everything about themselves by their IQ, even if more likely explanations are available. (For example, it is tempting to believe things like “I have a problem connecting with people, but that’s because my IQ is higher than theirs” when it’s actually lack of social skills; or “I feel bad, because my IQ is so high that I can see many bad things in this world” when it’s actually depression.) The life outcomes also depend on environment, and luck.
On the other hand, underestimating IQ also leads to false beliefs about the world. For example, after observing that some (high-IQ) children have great results at school, while other (low-IQ) children have bad results, an IQ denialist would have to invent an alternative explanation; for example, they could believe that the former are hard-working and the latter are lazy, or that the former have some unfair advantage (other than the IQ), depending on their sympathies.
Another problem is that even if you won’t take the test, you probably already have some beliefs about your intelligence. Those may be accurate, or not. Maybe you just got [un]lucky. Maybe the feedback you got reflects the prejudice of your parents and teachers more than your actual traits. I don’t see an advantage of keeping a (potentially wrong) belief, instead of taking the test. There is nothing you can do about your IQ, so maybe it is better to focus your attention on things you can change. But taking one test should not prevent you from doing that.
With regards to rationality, both high-IQ and low-IQ people can be pretty irrational, albeit in different ways. Smart people can invent really complicated excuses for doing the wrong thing.