 In this section and the next we will cover five important contributions to the emergence of ecological rationality. In this section, after reviewing Simon’s proposal for distinguishing between behavioral constraints and environmental structure, we turn to three historically important contributions: the lens model, rational analysis, and cultural adaptation. Finally, in  section 4,  we review the bias-variance decomposition, which has figured in the Fast and Frugal Heuristics literature  (section 7.2).