Pope Paul VI
Populorum Progressio §68
Populorum Progressio: On the Development of Peoples
68 We are deeply distressed by what happens to many of these young people. They come to wealthier nations to acquire scientific knowledge, professional training, and a high-quality education that will enable them to serve their own land with greater effectiveness. They do get a fine education, but very often they lose their respect for the priceless cultural heritage of their native land.
Source: Populorum Progressio (Vatican.va)