Of the current suite of top 20 languages at TIOBE (which for all its faults is as good as any other top-20 list), the ones that I know of that have heavy pedagogical backgrounds (that is, designed to teach students, not merely used to teach students because they were already popular) would be Python, Visual Basic, and Pascal, with Python's background probably being the most recent with its ABC predecessor, which some Googling suggests dates to the late 1980s, at which point the other two were already heading down the "industrial strength" path. Those would be the most interesting to test.

(If you're in a hurry to mention Scheme, that's #27. And on the list of "pedagogical languages" it would still be beaten by Logo at #23, which, frankly, is a sign we probably shouldn't trust the list at all below about #20....)