How does a study examining a narrow band of learning bear on gross volume of learning? It doesn't at all follow in an obvious way that opportunity cost genera

How does a study examining a narrow band of learning bear on gross volume of learning? It doesn't at all follow in an obvious way that opportunity cost generalizes like you seem to suggest. It's been observed that as people age, they trade fluid intelligence for crystallized intelligence. One slows down and goes deeper. Regarding my point about utility functions: no, it doesn't matter which you use, because none of them are adequate to the task at hand, which is really just figuring out how to live one's life in the absence of adequate utility functions.