In his book "Beyond Geography: The Western Spirit Against the Wilderness" (1980), Frederick W. Turner discusses the effect of those accounts in which white captives came to prefer and eventually adopt a Native American way of life; they challenged European-American assumptions about the superiority of their culture. During some occasions of prisoner exchanges, the white captives had to be forced to return to their original cultures. Children who had assimilated to new families found it extremely painful to be torn from them after several years' captivity. Numerous adult and young captives who had assimilated chose to stay with Native Americans and never returned to live in Anglo-American or European communities. The story of Mary Jemison, who was captured as a young girl (1755) and spent the remainder of her 90 years among the Seneca, is such an example.