This article summarizes developments in evolutionary biology relevant to
communication in general and introduces some implications for the
specific case of language. Another article, Design Features of Language,
develops these implications in detail . . .
Several important insights about communication result from these
calculations. First of all, adaptation by natural selection does not
escape from noise . . .
Second, the variables in these calculations are completely general. They
apply to signalers and receivers in all communication . . .
Third, these calculations confirm the results of all previous
calculations of the evolution of mutual interactions: neither signals nor
responses can spread when both are infrequent . . .
Fourth, optimization of communication in noise opens many questions about
adaptations for communication in different circumstances . . .
Finally, although communication is never expected to reach perfection,
honesty is expected to prevail . . .
Investigation of communication with a hypothetical absence of errors is
thus unrealistic . . .
It is also clear that all communication in noise is "inferential" and
Signals always arrive within a context of noise. A receiver decides to
respond based on its current state (including memory) and the sensations
it receives. These sensations include signals (usually honest but with
some noise) and relevant contexts (usually correct but with some noise).
If "inferential" implies decisions by a receiver and if "intentional"
implies associations for a receiver between a signal and its context, then
all communication is intentional, between animals as well as humans. The
decisions humans make in using language require complex criteria for
The distinctive features of human linguistic communication as opposed to
other forms of communication lie in the specific complexities of these
cognitive criteria, not in the importance of decisions or contexts in