What geographic feature made early americans consider isolation poloicies

Martin, a 32-year-old human relations administrator at a university, believes that all professors over age 50 are incapable of learning the new educational technologies and are content to keep presenting their same "tired, boring" lectures. he often expresses these views to other administrators and does not encourage any of the "older" faculty members to attend professional development meetings related to new teaching approaches nor does he suggest that the university send them to any of the technology conferences. martin is exhibiting