While keeping basic instruction separated by subject is necessary for teaching basic skills and concepts, there are huge ignored opportunities for interaction across subjects! Why isn't math used to teach music in elementary school? Prototyping concepts from engineering taught in art class? Why are high school students left on their own to connect the dots between chemistry equations and calculus concepts? Between organizing evidence for history papers and biology research? Adding interdisciplinary instruction, reserving space and time for creative exploration, and encouraging guided independent study would help break down these barriers in primary and secondary education.
To follow up on the softening of 'subject silos' in primary and secondary education, college majors should be made far less rigid. Creating an "ad hoc" or "interdisciplinary" course of university study shouldn't require miles of red tape. Graduation and major requirements should not require students to declare a major without having an opportunity to explore their interests and motivavtions. Any required distribution or freshman courses should encourage wide-ranging and creative paths of inquiry.
Many would still end up sticking to a traditional study of hard science or pure liberal arts. But by drastically reducing the implied separation between liberal arts and sciences, and between applied and theoretical math and science, students wouldn't feel pressure to pick a side if their interests don't fall neatly in one box. Not only would this increase the population of science- and math-educated students, but they would also have a background of creative, independent, and interdisciplinary thinking.