Behavior is sensible but not globally optimal: Seeking common ground in the optimality debate

Abstract

The disagreements among commentators may appear substantial, but much of the debate seems to stem from inconsistent use of the term optimality. Optimality can be used to indicate sensible behavior (adapted to the environment), globally optimal behavior (fully predicted from optimality considerations alone), locally optimal behavior (conforming to a specific model), and optimality as an empirical strategy (a tool for studying behavior). Distinguishing among these different concepts uncovers considerable common ground in the optimality debate.