Cultural norms so completely surround people, so permeate thought and action, that we never recognize the assumptions on which our lives rest. If birds were suddenly endowed with scientific curiosity they might examine many things, but the sky itself would be overlooked as a suitable subject; if fish were to become curious about the world, it would never occur to them to begin by investigating water. For birds and fish would take sky and the sea for granted, unaware of their profound influence because they comprise the medium for every act. Human beings, in a similar way, occupy a symbolic universe governed by codes that are unconsciously acquired and automatically different from the ways people conduct their affairs in other cultures.
As long as people remain blind to the sources of cultural norms, they are imprisoned within them. These cultural frames of reference are no less confining simply because they cannot be seen or touched. Whether it is an individual mentality that keeps an individual out of contact with his neighbors, or a collective mentality that separates neighbors of different cultures, both are forms of blindness that limit what can be experienced and what can be learned from others.
It would seem that everywhere people would desire to break out of the boundaries of their own worlds. Their ability to react sensitively to a wider spectrum of events and peoples requires an overcoming of such cultural parochialism. But, in fact, few attain this broader vision. Some have little opportunity for wider cultural experiences, though this condition should change as the movement of people accelerates. Others do not try to widen their experience because they prefer the old and familiar, seek from their affairs only further confirmation of the correctness of their own values. Still others avoid such experiences because they feel it dangerous to probe too deeply into the personal or cultural unconscious. Exposure may reveal how arbitrary many cultural norms are; such exposure might force people to acquire new bases for interpreting events. And even for those who do Seek actively to enlarge the variety of human beings to communicate with, there are still difficulties.
Cultural near-sightedness persists not merely because of inertia and habit, but chiefly because it is so difficult to overcome. One acquires a personality and a culture in childhood, long before he is capable of comprehending either of them. To survive, each person masters the perceptual orientations, cognitive biases, and communicative habits of his own culture. But once mastered, objective assessment of these cultural processes is awkward, since the same mechanisms that are being evaluated must be used in making the evaluations.
The examples of birds and fish are used to ________.

A. indicate that animals also have their respective cultures
B. explain that human beings occupy a symbolic universe as birds and fish occupy the sky and the sea.
C. illustrate that human beings are unaware of the cultural codes governing them
D. demonstrate the similarity between man, birds, and fish in their ways of thinking