1. 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

2. Overview Purpose Assumptions Machinery Simulations Results Discussion

3. 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

4. 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?

5. Assumptions Saussurean bi-directional sign: the “fundamental formal structure” underlying human language

6. 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

8. 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

9. Machinery: definitions (2) Communicative potential, interpretive potential For individuals s, h and objects o:

10. Machinery: definitions (3) Matrix of transmission probabilities Matrix of reception probabilities objects signals objects signals

11. Machinery: definitions (3a) Matrix of transmission probabilities objects signals

12. Machinery: definitions (3b) Matrix of reception probabilities objects signals

13. 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

14. Strategies: Imitator Transmission Reception Transmission^ Reception^ transmission and interpretation are not necessarily coordinated happy to imitate correct or incorrect behavior

15. Strategies: Calculator Transmission Reception Reception^ Transmission^ ‘optimal response’ to the observed sampling transmission and interpretation are not necessarily coordinated

16. Strategies: Saussurean TransmissionReception^ Transmission^ acquisition of transmission is the same as for Imitator transmission and interpretation are necessarily coordinated never observes/samples transmission

17. 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

18. Results: competitive

19. Results: Calculators only

20. Results: Imitators only

21. Results: Saussureans only

22. Discussion How is ambiguity modeled? –Homonomy, synonomy –Calculators can’t say ‘I don’t 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?

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