"It is impossible for the behavior of a single,isolated individual to reach any high degree of rationality. The number of alternatives he must explore is so great, the information he would need to evaluate them so vast that even an approximation to objective rationality is hard to conceive. Individual choice takes place in an environment of 'givens' - premises that are accepted by the subject as bases for his choice; and behavior is adaptive only within the limits set by these 'givens'."
Administrative behavior, Simon HA, 1945