Once Darwin and the early ethologists made it clear that nonhuman animals
also have elaborate communication, the focus has narrowed to the properties
of language that distinguish humans. Each such proposal has spurred students
of animal behavior to probe deeper for parallels among nonhuman animals. Some
organization in this process came when Charles Hockett (1960) presented a set
of 16 "design features," or distinctive properties, of human languages . . .
Cultural Transmission . . . The transmission and innovation of culture depend
on communication. Unless completely arbitrary, without advantages or
disadvantages for signalers or receivers, this communication evolves by the
same process of mutual optimization that applies to the evolution of all
communication . . .
Semanticity, Displacement, Arbitrariness, and Discreteness . . . contribute
to a continuum between emotive and cognitive behavior. All are widespread in
communication. All are disrupted by noise. Yet their use in noise sometimes
reveals a degree of cognition . . .
Prevarication . . . Because responding to signals should evolve to increase a
receiver's advantage in reproduction or survival, deceptive signals, which
have the opposite effect, must in general occur infrequently. Consequently,
deception often reveals evidence of a cognitive ability by signalers to
adjust the frequency of attempted deceptions by itself and others . . .
Hierarchical Organization . . . Chomsky (2005) recognized the importance of
categories when he proposed that merging is the crucial cognitive operation
of language. Merging, in the usual sense of simple combining, is nevertheless
too simple for his examples . . .
Yet it is not clear whether the relevant categories are recognized by
definition or by family resemblance. Furthermore, both in language and
social interaction, associations might sometimes be recognized as units,
without any parsing, in other words, without any analysis and merging of
parts, at all.
Consequently it seems unlikely that either language or social interaction is
organized entirely hierarchically. Nevertheless, this particular form
of organization has received special attention as a possibly fundamental
feature of language.
Language as Criteria for Responses . . . Classification of sensations is the
preliminary stage in the eventual classification of perceptions into the
components of language . . .
This perspective of language does not preclude human cognitive criteria that
quantitatively exceed those of nonhumans. Yet it has not identified a
qualitative cognitive capability that nonhumans entirely lack . . .
From Nonhuman to Human Language . . . Despite some animals' language-like
abilities, there is no clear evidence that these abilities are used for
communication in natural situations . . .
Perhaps, so far, neither the frequency of gestures nor responses have reached
the necessary threshold. . . .
Conclusion . . . The ultimate form of cooperation, language, would then just
need the impetus to get past the impasse of signalers without receivers and
receivers without signalers . . . After crossing the initial hurdle, natural
selection on the predispositions for language could take hold. Perhaps
than so far imagined, the use of language would flourish.