1. Complementary approaches: i) functional/behavioural studies; ii) (comparative) anatomical and physiological studies; iii) evolutionary studies, ethology.

2. Design features (Hockett 1960, Hockett and Altmann 1968, Coleman 2005).

a) Characteristics found in human and non-human communication:

• Vocal-auditory channel: but NB sign languages.
• Broadcast transmission and directional reception
• Rapid fading (transitoriness): carries a requirement for short-term memory of a signal
• Interchangeability: individuals can be both senders and receivers
• Total feedback: but NB sign languages
• Specialization: the communications do not serve any additional physiological function (cf. a dog panting)
• Semanticity
• Arbitrariness: but NB iconicity in sign languages
• Discreteness: the signal can be divided into repeatable parts. True of all kinds of signals.
• Traditional transmission: the communication system is learned

• Displacement: the referent may be removed in time or space. But apes may use communication in this way (e.g. Premack and Premack's "Sarah" learned to use symbols to ask for her desired fruit when it was not present) and bee dancing indicates the direction and distance of food sources or new hive location.
• Productivity: novel messages may be sent (i.e. not just a fixed repertoire of calls)
• Duality of patterning: 1) arrangements of minimal meaningless units into larger, meaningful units; 2) arrangements of meaningful units into more complex signals (e.g. Premack and Premack's "Sarah insert apple pail banana dish")
• Prevarication: speakers can - intentionally - make utterances that are false or meaningless. But it is now well-known that many animals use behaviour explicitly designed to deceive or mislead. Signing apes have been observed to use their sign language to send food-competitors away
• Reflexiveness: speakers can use a language to talk about language
• Learnability: a speaker of a language can learn any of a wide variety of languages
• Recursiveness (claim by Hauser, Chomsky and Fitch 2002)
  

a) Vervet monkeys (above): distinct calls to signal the presence of different predators: snakes (surround and watch) vs. terrestrial predators (e.g. leopard: run up a tree) vs. avian predators (hide in the bushes).	b) Cotton-top tamarin: sounds (chirps and whistles) combined into calls, which may be further combined according rules of "lexical syntax".

c) Bird songs: structurally complex, and having at least two levels of constituent structure (phrases and notes). But variations in songs appear not to be significant.
d) Dolphins: a variety of signals, but no evidence (yet) of structural complexity.
e) Humpback whale: more complex, structured songs. Changes from year to year are culturally transmitted. Unknown function.

Thus, it is clear that some degree of hierarchical structure (up to three structural levels), exhibiting duality of patterning, is far from unique to human language. However, recursive syntactic structures are not attested outside human language. More on this in lecture 4.

4. Comparative physiology

The larynx is lower in apes than monkeys, and lower in humans than apes. Bipedal locomotion → upright position → longer neck? The lowering of the larynx, together with shortening of the jaw, facilitates greater tongue mobility. Great apes have very mobile tongues, however. The human vocal apparatus is in several respects simpler than that of the great apes. Gelada monkeys have a very rich inventory of sounds (Richman 1976), combined into many rhythmic/melodic phrasal patterns (Richman 1987).

References

Coleman, J. S. (2005) Design features of language. In K. Brown, ed. Encyclopedia of Language and Linguistics, 2nd edition. Oxford: Elsevier. 471-5.

Hauser, M. D., N. Chomsky and W. Tecumseh Fitch (2002) The Faculty of Language: What Is It, Who Has It, and How Did It Evolve? Science 298 no. 5598, 1569-1579. http://dx.doi.org/10.1126/science.298.5598.1569

Hockett, C. F. and Altmann, S. (1969): see Demers, R. A. (1988) Linguistics and animal communication. In Newmeyer (1988), 314-335.
Dingwall, W. O. (1988) The evolution of human communicative behavior. In  Newmeyer (1988), 274-313.

Hockett, C. F. (1960) The origin of speech. Scientific American 293: 88 (Jan or Sept?) Reprinted in Human communication: language and its psychobiological bases: readings from Scientific American. San Francisco: W. H. Freeman and Co. 5-12.

Pepperberg, I. M. (1998) Talking with Alex: logic and speech in parrots. Scientific American presents: Exploring Intelligence. Vol. 9 (4). 60-65.

Richman, Bruce (1976) Some vocal distinctive features used by gelada monkeys. Journal of the Acoustical Society of America 60 (3), 718-724.

Richman, Bruce (1987) Rhythm and melody in gelada vocal exchanges. Primates 28 (2), 199-223.

Yu, A. C. and D. Margoliash (1996) Temporal hierarchical control of singing in birds. Science 273, 1871-1875.