Nursing, on the other hand, is in itself a vocation. One studies nursing, presumably, to become a nurse, and not usually as a means to some other end.

Therefore, a lack of boys' interest in math would be potentially different from a lack of boys' interest in nursing, in that innumeracy (just like illiteracy) tends to limit individual outcomes much more severely than lack of interest in a particular vocational path such as nursing.

What no one will admit is that these differences in preference may be matters of nature as well as nurture. Even if they aren't, these things change very slowly. I don't expect to see men equally represented in nursing, social work, or primary education at any point in the future except through a quota system.