Hauser, Chomsky and Fitch (2002) The Faculty of Language

Vanya Kapitonov

University of Melbourne

April 2, 2015

The goal

discuss the perspectives for research in the evolution of the faculty oflanguage

• broad: FLB, i.e., the communicative system

• narrow: FLN, i.e., the computational system underlying FLB

FLB ≈ FLN + SM + CI

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Central ideas

• recursion is the core of the computational system (FLN), and FLNis the distinguishing feature of human language

• this hypothesis is empirically testable

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Recursion: Computer Scientists

PHP Hypertext ProcessorGNU: [GNU’s Not Unix]’s Not Unix

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Renaissance Recursion

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Russian Recursion

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More precisely

N := 0|s(N)

L := Lex|F(L)

(after Ed Stabler)

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Three big puzzles

evolutionary How did humans get a system qualitatively differentfrom animals?

graduality Did the system evolve continuously or with saltations?

functional Was the system always used for communication, or wasit exapted?

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Assumptions

• defining for any language is a systematic correspondence betweensound (SM) and meaning (CI)

• the correspondence is mediated through the so called narrowsyntax (‘internal representations’)

• crucially, any language is discretly infinite and exhibits recursion

• animal communication systems lack recursion

Thereforerecursion is the domain which is the ‘deepest challenge for acomparative evolutionary approach to language’

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Assumptions

• defining for any language is a systematic correspondence betweensound (SM) and meaning (CI)

• the correspondence is mediated through the so called narrowsyntax (‘internal representations’)

• crucially, any language is discretly infinite and exhibits recursion

• animal communication systems lack recursion

Thereforerecursion is the domain which is the ‘deepest challenge for acomparative evolutionary approach to language’

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Assumptions

• defining for any language is a systematic correspondence betweensound (SM) and meaning (CI)

• the correspondence is mediated through the so called narrowsyntax (‘internal representations’)

• crucially, any language is discretly infinite and exhibits recursion

• animal communication systems lack recursion

Thereforerecursion is the domain which is the ‘deepest challenge for acomparative evolutionary approach to language’

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Assumptions

• defining for any language is a systematic correspondence betweensound (SM) and meaning (CI)

• the correspondence is mediated through the so called narrowsyntax (‘internal representations’)

• crucially, any language is discretly infinite and exhibits recursion

• animal communication systems lack recursion

Thereforerecursion is the domain which is the ‘deepest challenge for acomparative evolutionary approach to language’

9 of 17

Assumptions

• defining for any language is a systematic correspondence betweensound (SM) and meaning (CI)

• the correspondence is mediated through the so called narrowsyntax (‘internal representations’)

• crucially, any language is discretly infinite and exhibits recursion

• animal communication systems lack recursion

Thereforerecursion is the domain which is the ‘deepest challenge for acomparative evolutionary approach to language’

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Three Hypotheses

1 FLB is strictly homologous to animal communication

2 FLB is a derived, uniquely human adaptation for language

3 only FLN is uniquely human

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Three Hypotheses

1 FLB is strictly homologous to animal communication

2 FLB is a derived, uniquely human adaptation for language

3 only FLN is uniquely human

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Three Hypotheses

1 FLB is strictly homologous to animal communication

2 FLB is a derived, uniquely human adaptation for language

3 only FLN is uniquely human

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Three Hypotheses

1 FLB is strictly homologous to animal communication

2 FLB is a derived, uniquely human adaptation for language

3 only FLN is uniquely human F

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Sensory-Motor systems of animals

Contrary to initial expectations, animals have many features incommon with humans:

• categorical perception and discrimination of phonemes

• descended larynx for non-speech reasons (preadaptation?)

• imitation: vocal in birds and multimodal in cetaceans

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Conceptual-Intentional systems of animals

Evidence here is weaker:

• contradictory findings on the theory of mind in apes

• inconclusive data from vervet (and other) monkey calls◦ however, see work by Schlenker et al. (2014) on Campbell’s monkey

alarm calls

• calls are innate rather than learned, and contextually fixed

• the repertoire is incomparable with human vocabulary

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Discrete infinity and constraints on learning

The acquisition puzzle:

• from a finite input

• from positive only input

• the child correctly acquires the target system for infinite generation

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Discrete infinity and constraints on learning

Likewise with numbers: the kid “grasps the idea that the integer listis constructed on the basis of the successor function”.The apes, by contrast, do not (but rather learn each symbolindependently).Tamarins can learn finite-state, but not phrase-structure grammars.

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Discrete infinity and constraints on learning

Likewise with numbers: the kid “grasps the idea that the integer listis constructed on the basis of the successor function”.The apes, by contrast, do not (but rather learn each symbolindependently).Tamarins can learn finite-state, but not phrase-structure grammars.

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Discrete infinity and constraints on learning

Likewise with numbers: the kid “grasps the idea that the integer listis constructed on the basis of the successor function”.The apes, by contrast, do not (but rather learn each symbolindependently).Tamarins can learn finite-state, but not phrase-structure grammars.

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The ultimate goal includes answering questions like

• what are the general principles of the faculty of language

• why there are exactly these principles, and not others

• and therefore, why we observe a certain class of languages and notother imaginable ones

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Conclusion

• collaboration between linguists and biologists is desirable

• the hypothesis that FLB is shared and FLN is unique is testableand needs empirical investigation

• the comparative approach as the primary tool of that investigation

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Thank you!

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