How do we know that the world of the Olinka is very small? What detail on page 151 does Alice Walker give us that communicated this?

The Olinka villagers don't know about African American slavery or do not want to hear about it. They exist in a relative bubble due to their remoteness.Many villagers also assume that Nettie and Corrine are wives of Samuel’s.

The people believe that they have always lived in the same spot, growing cassava, groundnuts, yam, cotton, and millet.