If you ask, including in the Royal Society, ‘what proportion of kids with an IQ of X could master integration given a great teacher?’, you will get only blank looks and ‘I don’t think anyone has researched that’.
I think a better question is to ask: "How do you teach integration in a way that a lot of children can understand it for a reasonable time investment.
One of the most interesting parts of Science and Sanity (Alfred Korzybski, Map is Not the Territory originator) was the analysis of mathematics and physics, and in particular "On the Semantics of the Differential Calculus".
A better and more intuitive way to talk about Calculus, IMO.
The soon-to-be-resigning Dominic Cummings, advisor to the Education Secretary of the Coalition government, has released a 250-page manifesto describing the problems of the British educational establishment ("the blob" in Whitehall parlance) and offering solutions. I post this here because both his analysis and recommendations are likely to be interesting to LW, in particular an increased emphasis on STEM, broader knowledge of the limits of human reasoning and how they relate to managing complex systems, an appreciation for "agenty"-ness in organizational leadership, whole-brain emulation, intelligence enhancement, recursive self-improving AGI, analysis of human interactions on a firm evolutionary-psychological basis, and a rejection of fashionable pseudoscientific theories of psychology and society. Relevant extracts: