A Saussurean communication system exists when an entire communicating
population uses a single 'language' that maps states unambiguously ont
o symbols and then back into the original states. This paper describes
a number of simulations performed with a genetic algorithm to investi
gate the conditions necessary for such communication systems to evolve
. The first simulation shows that Saussurean communication evolves in
the simple case where direct selective pressure is placed on individua
ls to be both good transmitters and good receivers. The second simulat
ion demonstrates that, in the more realistic case where selective pres
sure is only placed on doing well as a receiver, Saussurean communicat
ion fails to evolve. Two methods, inspired by research on the Prisoner
's Dilemma, are used to attempt to solve this problem. The third simul
ation shows that, even in the absence of selective pressure on transmi
ssion, Saussurean communication can evolve if individuals interact mul
tiple times with the same communication partner and are given the abil
ity to respond differentially based on past interaction. In the fourth
simulation, spatially organized populations are used, and it is shown
that this allows Saussurean communication to evolve through kin selec
tion.