The Annual Conference of the Cognitive Science Society is happening next week with quite a but of language evolution stuff going on. On the run up I'll post a few evolutionary linguisticsy papers which will be presented. If you're presenting something please feel free to send me it to be covered here or write a guest post and I'll post it up!
Firstly, Bergmann, Lupyan & Dale are presenting a paper called "The Impact of Communicative Constraints on the Emergence of a Graphical Communication System". The paper can be seen here: http://www.tillbergmann.com/papers/cogsci_squiggle_bergmann_dale_lupyan.pdf
The authors present an experiment in which participants had to communicate using graphical symbols (called squiggles) of faces. The experiment worked as a communication game but also had generational turnover as in iterated learning experiments. They investigated the effect of different features of the input faces and the effect of changing the comprehension condition and how these affected the structure of the symbols that emerged.
The study used Dale & Lupyan's (2010) squiggle framework but used human faces as the input. Participants were to "squiggle" the face in just 5 seconds to prevent them from building representations which were too detailed and prevented participants from writing words etc. In the first experiment they found that participants used strategies such as using hair shape/length, face shape and features to differentiate between faces and different strategies were more common in some gender/age categories, e.g. women were more likely to be defined by their hair.
The second experiment was the same as the first one but differed in the "listening" round, where participants were to choose which original face a squiggle represented. In experiment 1, participants had to choose between any two faces, in experiment 2 they were to choose between an "opposite" face. Faces differed in being male or female and young or old. So in experiment 2 young females were always pitted against old males, and old females pitted against young males. This was to see if the environment in interrupting the squiggles effected how they were represented and interrupted. This experiment found that squiggles in experiment 2 had less detail in order to be successful, and the amount of complexity fell over generations. I suppose this is an effect of the differentiating features between faces being more salient in the second experiment where faces always differ in both age and gender. This shows that the context in which communication occurs can shape the structure and complexity of that communication.