Note on Terrestrial Orientation

November 1971

Note on Terrestrial Orientation

J. J. Gibson, Cornell University


The World Wide Web distribution of James Gibson’s “Purple Perils” is for scholarly use with the understanding that Gibson did not intend them for publication. References to these essays must cite them explicitly as unpublished manuscripts. Copies may be circulated if this statement is included on each copy.

Animals and men who live a good part of their lives outdoors, on whom the sun shines, and who notice sunrise and sunset, who are aware of the progress of the sun across the sky in the same way they are aware of the season of the year ñ such animals and men are always oriented. That is, they are oriented to the terrestrial earth as whole, not just to the familiar territory whose “landmarks” they recognize. They are aware of the reality that underlies the concepts of North and South without having these concepts; similarly they are aware of the time of day without having the concept of “time”.

Consider the theory of “sun compass orientation” in animals. It is said that the animal knows where North is by (1) observing the azimuth of the sun and then (2) compensating it for the time of day by consulting the internal clock. Birds, for example, are said to be able to “navigate” in this way. But this theory is not necessary. It is much too intellectual a process, and navigation is too anthropomorphic a description of it. The fact that some men use compass directions and clock times does not imply that animals have to do so. The sky is an invariant of the environment, and the path of the sun-in-the-sky is a higher-order invariant. The visual system of an alert animal is continuously attuned to this information.

Animals and primitive men not only notice the sun, they also notice the layout of the terrain as they get about. As they go from one glade to another, or one valley to the next, they see the optical transitions between one vista and the next that correspond to the path of locomotion between one place and the next, and at the same time they notice the invariants that specify the shape of the first layout, and the second, and the next, and so on. This is called “place learning” and animals are very good at it. (A place is identified by the layout and composition of the surfaces that semi-enclose it; this is more exact than “landmarks”.) After this kind of perceptual learning the animal is capable of homing, which I understand to mean that he can always get home from any place where he is.

Some psychologists have maintained that homing depends on the acquiring of a “cognitive map”. This seems to me almost as ridiculous as the theory that it depends on a chain of “turning responses”, for the notion of consulting a mental map is homonculitis at its worst. A map, like a compass, is a human aid to orientation, and this should not be confused with the fact of orientation. The observer who is oriented, moreover, does not so much have a cognition about home as see where home is. This is because he can see where he is relative to the environment. Home is there, in the distance, behind all the occluding surfaces, or walls, or trees, or whatever.

Those of us who are overcivilized easily become disoriented, or “lost” when away from home. The near (projected) environment is then not integrated with the far (unprojected) environment, with the world outside the limits of the visible surroundings. The cause, I believe, is a failure to have paid attention to the invariants of the environment, the invariants of the sky and the earth. There is available information in both for orientation to the terrain, not to “space” but to the surface of the earth. The latter is to be thought of as a connected set of places, each with a unique layout, and with the observer always at one of these places. Geographical orientation in man, and homing, migration, and navigation in animals, are intelligible in the light of this conception.

[see also “Note On the Act of Orienting and the State of Being Oriented” of April 1974]