I don't feel greater standardization of tests is the solution - look at England. They're the most tested country in the world, and I don't recall (and this would be a situation where I would ask someone else to cite a study if posible), that they're doing much better than anyone else.
I think a better solution would be to teach to projects. This is the approach that works well in art programs and universities; you give the students real projects to figure out - for instance, instead of telling a student to run through an ever increasing number of math problems every night, give them a three week long project to build and mathematically predict the performance of a small trebuchet or a water cannon or something.
One of the things I keep seeing pop up in the news is all the alarmist people going "oh my god, our students aren't interested in their work! what is going on!?". The reason most kids aren't interested is because the work is mind numbingly boring - it's not about learning, it's about rote memorization. Give students a chance to figure things out. On top of that, encourage group work - you can't possibly teach to every student's needs effectively, so bring the students together so that the ones who pick it up quicker can have an opportunity to help those that are farther behind. Get classrooms to be interactive, instead of just bubbles where students run through as many problems as they can memorize before they go home and forget it all. Encourage them to actually try and design crazy spaceships and hover boots - just because you don't think it's possible doesn't mean that the kids don't learn real things from the research that they do on the subject. I tried to design hover boots in 7th grade for a class project, and through research I learned about the properties of magnetism, the periodic table, and different properties of different elements. It was WAY more interesting than sitting in a classroom for two hours while the teacher repeated the same info over and over, made me do boring labs, and made me straight up memorize the whole table for a quiz which would go into my record and help to shape the rest of my entire life. :\
P.S. IQ numbers are misleading. I don't personally like to subscribe to them as a measure of intelligence.