MIT Encyclopedia of the Cognitive Sciences - Cryptome

22 Animal Cognition
Papers from the Tenth Regional Meeting of the Chicago Linguistic
Society. Chicago: Chicago Linguistic Society.
Langacker, R. (1966). On pronominalization and the chain of command.
In W. Reibel and S. Schane, Eds., Modern Studies in
English. Englewood Cliffs, NJ: Prentice Hall.
Lasnik, H. (1976). Remarks on coreference. Linguistic Analysis
2(1).
Levinson, S. C. (1987). Pragmatics and the grammar of anaphora.
Journal of Linguistics 23: 379–434.
McCawley, J. (1979). Presuppositions and discourse structure. In
C. K. Oh and D. A. Dinneen, Eds., Presuppositions. Syntax and
Semantics, vol. 11. New York: Academic Press.
Prince, E. (1981). Towards a taxonomy of given-new information.
In P. Cole, Ed., Radical Pragmatics. New York: Academic
Press, pp. 233–255.
Reinhart, T. (1976). The Syntactic Domain of Anaphora. Ph.D.
diss., MIT.
Reinhart, T. (1983). Anaphora and Semantic Interpretation.
Croom-Helm and Chicago University Press.
Wexler, K., and Y. C. Chien. (1991). Children’s knowledge of
locality conditions on binding as evidence for the modularity of
syntax and pragmatics. Language Acquisition 1: 225–295.
Animal Cognition
See ANIMAL NAVIGATION; COMPARATIVE PSYCHOLOGY; PRI-
MATE COGNITION; SOCIAL PLAY BEHAVIOR
Animal Communication
Fireflies flash, moths spray pheromones, bees dance, fish
emit electric pulses, lizards drop dewlaps, frogs croak, birds
sing, bats chirp, lions roar, monkeys grunt, apes grimace,
and humans speak. These systems of communication, irrespective
of sensory modality, are designed to mediate a flow
of information between sender and receiver (Hauser 1996).
Early ethologists argued that signals are designed to
proffer information to receptive companions, usually of
their own species (Tinbergen 1951; Hinde 1981; Smith
1969). When a bird or a monkey gives a “hawk call,” for
example, this conveys information about a kind of danger.
And when a redwing blackbird reveals its red epaulette during
territorial disputes, it is conveying information about
aggressive intent. Analyses of aggressive interactions, however,
revealed only weak correlations between performance
of certain displays and the probability of attack as opposed
to retreat, leaving the outcome relatively unpredictable
(Caryl 1979). Thus, while information transfer is basic to all
communication, it is unclear how best to characterize the
information exchange, particularly because animals do not
always tell the truth.
In contradistinction to the ethologists, a new breed of animal
behaviorist—the behavioral ecologists—proposed an
alternative approach based on an economic cost-benefit analysis.
The general argument was made in two moves: (1)
selection favors behavioral adaptations that maximize gene
propagation; and (2) information exchange cannot be the
entire function of communication because it would be easy
for a mutant strategy to invade by providing dishonest information
about the probability of subsequent actions. This
places a premium on recognizing honest signals. Zahavi
(1975) suggested a mechanism for this, using the following
recipe: signals are honest, if and only if they are costly to produce
relative to the signaler’s current condition and if the
capacity to produce honest signals is heritable. Consider the
anti predator stotting displays of ungulates—an energetically
expensive rigid-legged leap. In Thompson’s gazelle, only
males in good physical condition stot, and stotting males are
more likely to escape cheetah attacks than those who do not.
Departing slightly from Zahavi, behavioral ecologists
Krebs and Dawkins (1984) proposed that signals are
designed not to inform but to manipulate. In response to
such manipulation, selection favors skeptical receivers
determined to discriminate truths from falsehoods. Such
manipulative signaling evolves in situations of resource
competition, including access to mates, parental care, and
limited food supplies. In cases where sender and receiver
must cooperate to achieve a common goal, however, selection
favors signals that facilitate the flow of information
among cooperators. Thus signals designed to manipulate
tend to be loud and costly to produce (yelling, crying with
tears), whereas signals designed for cooperation tend to be
quiet, subtle, and cheap (whispers).
Turning to ecological constraints, early workers suggested
that signal structure was conventional and arbitrary.
More in-depth analyses, however, revealed that the physical
structure of many signals is closely related to the functions
served (Green and Marler 1979; Marler 1955). Thus, several
avian and mammalian species use calls for mobbing predators
that are loud, short, repetitive, and broad band. Such
sounds attract attention and facilitate sound localization. In
contrast, alarm calls used to warn companions of an
approaching hawk are soft, high-pitched whistles, covering
a narrow frequency range, only audible at close range and
hard to locate (Marler 1955; Klump and Shalter 1984). The
species-typical environment places additional constraints on
the detectability of signals and the efficiency of transmission
in long-distance communication, selecting for the optimal
time of day and sound frequency window (Marten,
Quine, and Marler 1977; Morton 1975; Wiley and Richards
1978). To coordinate the movements of groups who are out
of sight, elephants and whales use very low frequency
sounds that circumvent obstacles and carry over long distances.
In contrast, sounds with high frequency and short
wavelengths, such as some alarm calls and the biosonar signals
used by bats and dolphins for obstacle avoidance and
prey capture, attenuate rapidly.
The design of some signals reflects a conflict between natural
and sexual selection pressures (Endler 1993). An elegant
example is the advertisement call of the male Tungara frog
(Ryan and Rand 1993). In its most complete form, one or
more introductory whines are followed by chucks. Because
females are attracted to the chucks, males who produce these
sounds have higher mating success. But because frog-eating
bats can localize chucks more readily than whines, frogs producing
chucks are more likely to be eaten. They compromise
by giving more whines than chucks until a female comes by.
There are many such cases in which signal design is closely
related to function, reflecting a tightly stitched tapestry of factors
that include the sender’s production capabilities, habitat