Dialects do belong [...] to very definetely circumscribed social groups, homogeneneous enough to secure the common feeling and purpose needed to create a norm.
- Sapir (1921), a pag.150

[...] dialects arise not because of the mere fact of individual variation but because two or more groups of individuals have become sufficiently disconnected to dirft apart, or independently, instead of together.
- Sapir (1921), a pag.150

[...] no language can be spead over a vast territory [...] without showing dialectic variations , for it is impossible to keep a large population from segregating itself into local groups, the language of each of which tends to drift independently.
- Sapir (1921), a pag.151

Under primitive conditions the political groups are small, the tendency to localism exceedingly strong. It is natural, therefore, that the languages of primitive folks [...] are differentiated into a great number of dialects.
- Sapir (1921), a pag.151