certain meanings to certain sounds. And since one is stimulated
to expression primarily by the desire and necessity of
communication of ideas a premium is put upon uniformity.
It is of no use to use a language if it conceals one's thoughts.
In consequence, within a group individual variations, unless
for reasons already discussed they happen to lend themselves
to ready assimilation by the group, will be mere slips of the
tongue. They will be discarded and forgotten, or, if the individual
cannot rid himself of them, will like stammering or stuttering or
lisping be set down as imperfections and social
handicaps. The uniformity of language within groups whose
individual members have much communication with each
other is thus to a certain extent guaranteed. A man who is
utterly individualistic in his language might just as well have
no language at all, unless for the satisfaction of expressing to
himself his own emotions.[1] Language is learned from the
group among whom one moves, and those sounds and senses
of words are, on the whole, retained, which are intelligible to
the group. Those sounds and meanings will best be understood
which are already in use. No better illustration could
be found of how custom and social groups preserve and enforce
standards of individual action.

[Footnote 1: There have been a few poets, like Emily Dickinson,
or mystics like Blake, some of whose work exhibits almost complete
unintelligibility to most readers, though doubtless it had a very
specific meaning and vividness to the writers concerned.]

The obverse of the fact that intercommunication promotes
uniformity in language is that lack of communication brings
about language differentiation. The less the intercommunication
between groups, the more will the languages of the
groups differ, however uniform they may be within the groups
themselves. The most important factor in differentiation of
language is local differentiation. In some European countries
every village speaks its own dialect. In passing from one
village to another the dialects may be mutually intelligible,
but by the time one has passed from the first village in the
chain to the last, one may find that the dialect of the first
and last are utterly unintelligible to each other. A real break
in language, as opposed to dialect variations, occurs where
there is a considerable barrier between groups, such as a
mountain range, a river, a tribal or political boundary. The
more