Frog Leaps and Human Noises: An Optimality Theory Approach to Cultural Change Andreas P. Giannakoulopoulos Abstract: Optimality Theory came into being during the last decade of the 20th century as a linguistic theory seeking to explain language phenomena in a rather revolutionary way: grammars would no more consist of inviolable strict rules to be learnt by heart, but rather are to be thought of as sets of violable constraints which determine optimal output types among competing ones. In this paper an attempt is made to extract this explanatory mechanism from the linguistic field and implement it in decision-making areas involving cost and efficiency. This attempt is substantiated by the construction of a model which evaluates sets of candidate outputs in terms of optimality in particular situational settings. Considerable interest has been given to the flexibility of the model, as to formalize quite diverse aspects of human behavior, all of which share in common a strong disposition towards economy constraints and effort versus utility equilibria. Individual preferences, as well as previous experiences, are crucial factors for the evaluation of candidates which takes place under a combination of quantitative methods along with standard Optimality Theory techniques. Optimal outputs in turn, constitute behavioral patterns and eventually lead to cultural change. The concept of violable constraints is shown to resemble common-sense procedures in decision-making, thus the model functions in both a theoretic and an operational perspective.