Because they were driven away from their homelands by force
John Dewey, American educator, wrote the very influential book called "Democracy and Education". He was a wise man with strong political and social issues, that's why his ideas are considered to be the most influential in education and social reform throughout the educational history of America. He is often associated with a terms of pragmatism and functional psychology.
At this time in the Neolithic, c. 7000-6,000 B.C.E., people were often buried under the floors of homes, and in some cases their skulls were removed and covered with plaster in order to create very life-like faces, complete with shells inset for eyes and paint to imitate hair and moustaches.
