be seen whether they can also learn to produce rule-governed messages, but an ability to understand and respond appropriately to messages whose meaning requires comprehension of the rules as well as of the individual elements is certainly an important step in the direction of combinatorial productivity in animal communication.
In the thoughtful discussion of Herman's experiments at the conference, it was pointed out that we scientists whose native language is English tend to assume that grammatical rules providing combinatorial productivity must necessarily involve word order or the temporal sequence of other signals. This type of rule is easy to manipulate experimentally, but it is by no means universal among human languages. Many languages use inflection of key words to convey grammatical relationships, such as which noun is actor or object and who performs a certain action. The fact that this sort of grammatical rule is so widespread might mean that it is in some ways a simpler and perhaps even an easier way to combine words meaningfully. Would apes, parrots, dolphins or other animals learn more readily to communicate with combinatorial productivity if the rules involved modifications of signals rather than their temporal order? This notion was one of many potentially fruitful ideas that took shape during the conference, and readers of the following chapters will find abundant and comparable food for thought.
Donald R. Griffin
The Rockefeller University
Griffin. D. R. ( 1984). Animal thinking. Cambridge, MA: Harvard University Press.
Harré R., & Reynolds. V. (Eds.). ( 1984). The meaning of primate signals. New York: Cambridge University Press.
Herman L. M. ( 1980). "Cognitive capacities of dolphins". In L. M. Herman (Ed.). Cetacean Behavior mechanisms and functions New York: Wiley.
Miller G. A. ( 1967). The psychology of communication. New York: Basic Books.