The British and American higher education systems are different, in Britain a person is offered a place at universty to study a certain subject such as law or psychology whilst still at 6th form at high school or a 6th form college. It is normally expected that a student will continue to study this subject until they graduate.
In American, as I understand it, a person will be offered a place at a university but is then able to choose to study a number of courses from those that are offered by that university. They may study some English Literature, Math, Physics and so on.This will then become their major.Subjects such as law and psychology are studied after graduation in graduate or Proffesional school.
So a British student goes to university to study a particular subject and so it appears more often in British English.