[kragen]

Only if Harvard's admissions don't work very well—for example, because intelligence isn't scalar or is hard to measure, or because they use the wrong measurements, or because they get turned down by a lot of kids they admit, or because a lot of kids they would admit aren't applying. My high school had 2000 students, which I think is typical to large in the US. If we're talking about multiple smart kids at an "average" 1000-person high school, then those are the top 1/500 or top 1/250 of the population. Harvard admits about 2000 students per year and enrolls about 1700 of them, about ⅞ from the US. That's about 1/2000 of the 4-million-or-so US graduates per year.

https://college.harvard.edu/admissions/admissions-statistics

So the average US high school has about 0.5 kids who get admitted to Harvard, about one every 8 years. So if Harvard is admitting exactly the smartest US kids (plus a smaller number of even smarter international students), all of them are probably smarter than any of the smart kids at your high school.

But they probably aren't. I didn't apply to Harvard, myself. If I had, I probably wouldn't have gotten in.