There are two different kinds of optimization: selection and rationality optimization. Selection optimization characterizes competition in human and nonhuman societies sharing the same market or niche. Rationality optimization , on the other hand, characterizes human and nonhuman decision making processes. The two kinds of optimization generate the same result: agents end up behaving efficiently. Nonetheless, we should not downplay the differences between the two kinds of optimization. Otherwise, we would fail to capture the role of rationality in the development of the organism and possibly its implication for evolution.