The document summarizes an experiment that explored the emergence of simple communication systems through an iterative game. In each round, participants were given geometric shapes to represent and had to develop message codes to coordinate their assignments. Larger symbol and letter sets facilitated more common codes emerging over time. Compositional grammars that organized features into messages proved more persistent than non-compositional ones, especially in changing environments. The experiment provided insights into how linguistic coordination and grammatical structures can develop through iterative interactions under economic pressures.

1. The Emergence of Simple Languages in an Experimental Communication Game - Reinhard Selten and Massimo Warglien (2007) (Plus – Iteration Experiments) * Complete with the obligatory unnecessary primate pictures *

5. Player 1 Player 2 Subjects then assign each symbol a message constructed from a string of permissible letters S Z SR ZSR SR ZS SRS RZS SS RR R SZS RZR ZSR RS SR ZR RS ZSR SRZ ZS SS RZZ SS R R SS RRS Z RSR

6. Player 1 Player 2 One subject and one figure are randomly chosen

7. Player 1 Player 2 RS The message specified by the sender’s code is then transmitted to the other player

8. Player 1 Player 2 RS RS Currency +10 Currency +10 Payoffs: Players receive a payoff of 10 units of currency each if the communication is ‘successful’ i.e. if the two codes match

9. Player 1 Player 2 RS RZ Zero Zero No payoff is received if the codes do not match X

11. Player 1 Player 2 After each period both players find out whether the communication was successful RS RS Success!

12. Player 1 Player 2 If the communication was not successful… RS Subjects receive feedback on the hidden aspects of the game Sender – the receiver's code Receiver – the symbol that was chosen

13. Player 1 Player 2 Subjects then have a chance to change their codes before the next period S Z SR ZSR SR ZS SRS RZS SS RR R SZS RZR ZSR RS SR ZR RS ZSR SRZ ZS SS RZ SS R R SS RRS Z RSR

14. Player 1 Player 2 S Z SR ZSR S ZS RS RZ SS RR R SZS RZR ZR RR SSS SR RZ ZR SZ ZRS SS RZZ SS RZZ R SS RS Z RSR

22. A Noncompositional Grammar Graphemes ‘R’ and ‘S’ represent Circle and Triangle respectively The number of letters indicates the presence or lack of inserts The type of insert is determined by the presence or lack of matching final letters

23. A Compositional Grammar Graphemes ‘R’ and ‘S’ represent Circle and Triangle respectively The type of insert is determined by the final letters