Biological Evolution of the Saussurean Sign as a Component of the Language Acquisition Device

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Biological Evolution of the Saussurean Sign as a
Component of the Language Acquisition Device

• James R. Hurford
• University of Edinburgh, Scotland
• Presented by Laurel Preston
• May 17, 2006
• Linguistics 580, Professor Lewis

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Overview

• Purpose
• Assumptions
• Machinery
• Simulations
• Results
• Discussion

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Purpose

• To propose an explanatory model of early stage
  language.
• Nativist component innate strategy for
  acquiring a communication system
• Functional component evolutionary mechanism
  whereby communicative success confers a selective
  advantage

Summary of model Communicative success confers
a selective advantage Innate Saussurean strategy
is the most advantageous for communicative
success Saussurean individuals invade population,
displacing rivals
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Simulation Summary

• Initial populations with defined communicative
  behavior
• Individuals with different strategies for
  language acquisition
• Assume communicative success confers selective
  advantage
• Discover which individuals come to dominate the
  population?

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Assumptions
Saussurean bi-directional sign the fundamental
formal structure underlying human language
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Assumptions, continued

• Language evolved for the purpose of communication
• Early stage language existed no syntax
• Acquisition strategy can be transmitted
  genetically
• Darwinian natural selection
• Mendelian genetics
• Transmission and reception are logically distinct

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(No Transcript)
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Machinery definitions

• Successful communication
• any encounter between individuals where one (the
  transmitter), while mentally attending to a
  particular concept, carries out some observable
  act (which may be a gesture, a vocalization, or
  whatever), and another individual (the receiver),
  as a result of observing this act comes to attend
  to the same concept. p.191

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Machinery definitions (2)

• Communicative potential, interpretive potential

For individuals s, h and objects o
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Machinery definitions (3)

• Matrix of transmission probabilities
• Matrix of reception probabilities

objects
signals
signals
objects
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Machinery definitions (3a)

• Matrix of transmission probabilities

objects
signals
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Machinery definitions (3b)

• Matrix of reception probabilities

signals
objects
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Machinery definitions (4)

• Strategy
• Component of the Language Acquisition Device
• Individuals with different strategies will
  observe the same data but construct different
  internal representations
• strategy does not imply conscious intention or
  control

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Strategies Imitator
Transmission Reception
Transmission Reception

• transmission and interpretation are not
  necessarily coordinated
• happy to imitate correct or incorrect behavior

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Strategies Calculator
Reception Transmission
Transmission Reception

• optimal response to the observed sampling
• transmission and interpretation are not
  necessarily coordinated

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Strategies Saussurean
Transmission
Reception Transmission

• acquisition of transmission is the same as for
  Imitator
• transmission and interpretation are necessarily
  coordinated
• never observes/samples transmission

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Simulations

• Given starting populations with different CPs
• Random, Emergent, Perfect
• 30 individuals, 5 objects, 7 signals
• 20 simulations of each scenario 100 generations
• 3-way competitive simulations 10 individuals
  from each strategy population
• 2-way competitive simulations 15 individuals
  from two of the strategy populations at a time I
  vs C, C vs S, I vs S
• 1-way non-competitive simluations

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Results competitive
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Results Calculators only
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Results Imitators only
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Results Saussureans only
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Discussion

• How is ambiguity modeled?
• Homonomy, synonomy
• Calculators cant say I dont know they have
  to guess
• I do not believe that I have loaded the dice by
  idealizing any of these strategies in such a way
  as to render it less (or more) successful
  (p.221)
• Do we agree?

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Calculator deriving reception behavior from
observed transmission behavior
signals
objects
signals
objects