first current issues essay
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*Complete with the obligatory unnecessary primate pictures
*The Emergence of Simple Languages in an Experimental Communication Game- Reinhard Selten and Massimo Warglien (2007)
(Plus – Iteration Experiments)
The Paper
This bears some similarities to the Galantucci and Garrod et al papers but is more concerned with the emergence of linguistic systems than the emergence of symbols
Uses a economic game to apply pressures to the emergence of a communication system Presents language as the product of the competing forces of
communicative needs and personal expenditure The experiment explores the relationship between communication
costs/benefits and the emergence of language Participants are encouraged to look at communication as an economic
game Design aims to filter out other socio-linguistic reasons for
communication to focus on how economy and self interest act as a selective pressure on emergent codes and grammars
The Experiment
Subjects are on separate computer terminals The rules of the game are explained to them in advance (in most cases) The subjects are playing for money There is no communication except the limited communication allowed
by the experiment Communication is limited and the goal of the game is to
harmonise the two separate individual codes into one shared code
Co-operation to produce the code is the only way of making individual money No specific target or goal but personal accumulation No overt way to lose, but you can fail to accumulate Strategies are required to make the communicative limitations work
•In each round..
Player 1 Player 2
Subjects are presented with a
list of geometrical
shapes with a range of features
Player 1 Player 2
Subjects then assign each
symbol a message
constructed from a string of
permissible letters
RS ZSR RZR SZS R
RR SS RZS SRS ZS
SR ZSR SR Z S
RSR Z RRS SS R
R SS RZZ SS ZS
SRZ ZSR RS ZR SR
Player 1 Player 2
One subject and one figure are randomly chosen
Player 1 Player 2
RS
The message specified by the sender’s code is then transmitted to the other player
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
Player 1 Player 2
RS RZ
Zero Zero
No payoff is received if the codes do not match
X
Player 1
•In addition to the rewards for a successful communication, the sender of the message bears a cost for the message
•The cost is two units per letter used, so longer messages carry a greater cost to the sender
RS
Currency -4
R=2, S=2, Cost = 4
Player 1 Player 2
After each period both players find out whether the communication was successful
RS RS
Success!
Player 1 Player 2
If the communication was not successful…
RS
Subjects receive feedback on the hidden aspects of the gameSender – the receiver's codeReceiver – the symbol that was chosen
Player 1 Player 2
RS ZSR RZR SZS R
RR SS RZS SRS ZS
SR ZSR SR Z S
RSR Z RRS SS R
R SS RZ SS ZS
SRZ ZSR RS ZR SR
Subjects then have a chance to
change their codes before the
next period
Player 1 Player 2
RR ZR RZR SZS R
RR SS RZ RS ZS
S ZSR SR Z S
RSR Z RS SS R
RZZ SS RZZ SS ZRS
SZ ZR RZ SR SSS
Versions of the Experiment
There were four versions of the experiment:
Version I Limited letter set 1 session
Version II Medium letter set 1 session
Version III Medium letter set 2 sessions
Version IV Medium letter set +
Larger letter set (second session)
2 sessions, second session had different symbol set
All of the letter and symbol sets became progressively larger over the course of the game
Results: Impact of the size of the repertoire
• In Experiment I they experienced an unexpectedly low amount of common code correlations
• This was significantly reduced in the subsequent experiments with larger sets of letters
• They concluded that a large repertoire of possible signs/meanings was necessary for the emergence of a common code
The Influence of Differentiation and Efficiency on Payoffs
• Simpler codes result in larger payoffs• A high degree of asymmetry causes low changes and
high agreement– Low changes and high agreement lead to high payoffs– Solving the task requires teaching/leading by one player
• What are the implications if asymmetry is an important factor in the emergence of code systems?
Grammatical Effects
The experiment looked at the effect of grammaticality effects on the efficiency of the game
Levels of grammaticality: Ungrammatical: No grammatical structure, 1-to-1 mapping of
symbols to individual letter sequences Noncompositional Grammar: Features are expressed by
individual graphemes, association or order, but not in a compositional framework.
Compositional Grammar: A grammar formed by the mapping of features to individual graphemes and then arranging them in a fixed order
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
A Noncompositional Grammar
Graphemes ‘R’ and ‘S’ represent Circle and Triangle respectively
The type of insert is determined by the final letters
A Compositional Grammar
Communication and Compositionality
• Under consistent environments, most grammars did not become compositional
• More compositional grammars were formed in the second session Experiment IV than Experiment III
– Novelty forced compositional grammars to emerge
• Compositional grammars were more persistent– 100% persistent, as opposed to uncompositional grammars which were 0%
persistent• In Experiment IV few compositional grammars were formed, but those that
did were highly successful– With grammar, average payout 635 Talers– Without grammar, average payout 211 Talers
Summary of Key Results
1. The size of the linguistic repertoire seems important for linguistic coordination
2. In a repetitive environment, cost efficiency and role asymmetry enhance communicative success
3. In stable environments noncompositional grammars are simpler and easier, but in a changing environment compositional grammars have the advantage
4. Compositional grammars appear to not be an automatic communicative strategy. In stable environments there is little pressure to form a compositional grammar
Issues with the Experiment
Lots of overlapping versions of the experiment and some unclear design
Measurement of ‘common code’ Weights of the experiment and the methods of reward Defining compositional and non-compositional
grammars It does away with sociolinguistic reasons for
communication The expansion of the symbolic repertoire is unnatural
Experimental Tests of Communication: Iteration meets Game Playing
We are seeing a new paradigm in which the experimental techniques of psychology, iteration and evolutionary game theory are used to explore the emergence of communication systems
How does this paradigm build on existing research methods?
• Unconscious and conscious formation of systems
• The line between passive and active cultural transmission
• Use of evolutionary pressures
• Linear and horizontal models
What are the natural limits of this paradigm? How does it relate to evidence from computer
modelling?
Conducting Research in Light of these Experiments
Ecological validity – does it matter that these experiments might not replicate an authentic evolutionary environment?
Exploring alternative explanations for results We need to account for the psychological complexity of
communicative interactions
Integration of the horizontal and vertical dimensions of iteration Experimenting with genuine ontogeny is difficult Defining ‘generations’ in an experiment
Scale and participation
Potential New Designs
Amalgamations of some of the individual designs
Some iteration/communication experiments are essentially a combined sequence of input-output experiments Using information
technology to link individual results
Community based experiments
Combine code experiments and symbol experiments