...I still believe that these same kids could learn tensor calculus if taught correctly earlier in life.)
I wish this was true. I really do. But I don't think it is. I don't think that most people can even learn differential/introductory calculus (and this is okay. People have different talents). I wish they could. But I just don't think so.
Here's why:
Some people will never be able to be starters on the college varsity basketball team. Some people will never run a mile in under four and a half minutes or 100m in under 11 seconds or do a triple axel, no matter how hard they train. Not everyone can make the cut for a pro baseball team (which is why starting salaries are over $300,000 a year). They might not have the right kinds of muscles or the right body shape or enough strength (or all of the above).
Why should cognitive achievement be any different?
I understand the desire to include everyone (or not exclude them because of the circumstances of their births). It feel elitist. But being honest isn't elitist. Doing calculus requires that you know your geometry and algebra (I&II)
really well. Plus it requires a lot of reasonably difficult arithmetic and an understanding of functions. You need You need to be able to work with these things without thinking too much so that your mind is able to focus on the bigger picture (the calculus) instead of its component parts (the lower math that you use to make the calculus work).
People who can't retain all of that stuff and keep it running in memory at the same time will have a serious problem with just the computational aspects of calculus (never mind applying concepts to word problems or real-life problems). And that's okay.
The problem, I think, is our society's ruthlessness and its attitude toward academic pursuits (get a degree and you'll earn more money!) rather than on being honest about identifying people's talents and steering them toward them.
