The recently developed view of ecological rationality places a strong focus on the structural properties of environments. The human language faculty is thought by some researchers to be shaped not by the environment but by boundary conditions internal to the mind, in the sense that the linguistic system is an optimal solution for meeting the requirements of transforming thought between the conceptual-intentional system and the articulatory-motor system. The idea of the adaptive toolbox leads us to consider a collection of simple mechanisms drawn on by the cognitive system. This chapter contrasts classical rationality with ecological rationality and argues that the latter offers a far more productive concept to understand human decision making. The cognitive system needs to be viewed more as an ecologically rational bag of tricks and less in terms of a formally motivated calculating device adhering to general principles of classically rational.