Our schools had IQ info on all students, obtained through a variety of standardized tests, but the information was never, ever shared with students, or even, I think, parents. I only found out about it as an adult, when a childhood friend went into education and got a job in our old school district.

When you think about it, sharing it with students is much more likely to cause harm than good. Score low and you get discouraged; score high and you think you can coast.