To address Trevors Point:
Did you ever hear, "you have the potential to be doing much better. if you'd apply yourself, you would be doing much better." ? I heard it. Didn't do much good. I've said it A LOT. I've heard other teachers say it to other students. I've also said almost exactly what you claim you think you needed to hear. Things along the lines of, "You are getting a C (or D, F, B, A-) You should be getting an A. You are smarter than the work you produce. If you keep doing this, you end up getting punished with more boring courses. The excitement comes in application of principles. Keep this up and your most advaced class will deal with how to balance a check-book. Boring. Do the work and our physics classes build boats, rockets, take apart cameras, etc..." This conversation has been had at varying levels of brutality and care. It is a common conversation. We try to find new ways to say it. It doesn't work as often as we'd like. In fact it is pretty rare to get any change*.
We have actually said to heck with it (really did) and put a few of these kids in higher level classes because the family and a doctor claimed the kids were of higher aptitude and simply need a challenge. These kids failed miserably. The teachers were told to make special care and make sure the kid was treated fairly by their classmates. We are a small school. The teachers know the student body. To have no conversation on the topic with staff would be a bit silly. The kids failed the additional challenge. So oddly enough, putting a kid earning average to below average grades in entry or average classes into advanced classes doesn't necessarily work.
To Bob's Point:
<<<"Everyone on this list lauds evolutionary theory over creationism. Yet somehow many have become convinced that all these kids have lost the intelligence we had at their age in just a few generations. ">>>
Come on. What percentage of the adult population has the talent-level of those on this list? This gift has not been lost in a couple of generations. It has remained, but likely in nearly the same percentage of people. I would argue that is what tracking is for. Test kids, separate them into math classes by their ability. For the BCs, a kid isn't locked into 'dummy math' throughout high school simply due to their original placement. The following year's options (with course electives etc...) are always based on pre-req's. Pass a class, then choose your next course.
*One exceptional exception did figure it out after his sophomore year. He finished h.s. with calc 2 (taking Calc 1 as a class and on his own figuring out how to pass the calc 2 test), 1 physics class & an intro to engineering class became math major & just received an award for excelling as an instructor in recitation sessions. His freshman year he asked about mercury switches. I asked why he was curious. WIth a bit of digging, I found the kid had both The Anarchists Cookbook and The Amateur James Bond. Scary as a freshman. HE figured it out. I tried to push him. His math teachers tried to push him. For whatever reason, the switch went on.