Understanding, assessing, and simulating behavior requires knowledge of the precepts that are explicitly or implicitly orienting behavior. Human actors can be viewed as (conscious) self-organizing systems attempting to remain viable in a diverse environment containing other self-organizing systems (other human actors, organisms, ecosystems, etc.), all driven by their own viability (sustainability) interests. These fundamental system interests, or basic orientors, have emerged in response to general environmental properties and are therefore identical across self-organizing systems: existence, effectiveness, freedom of action, security, adaptability, coexistence. Even in simulated actors learning to 'survive' in a difficult environment, the basic orientors emerge in the (simulated) evolutionary process - but different actors may evolve into different 'cultural types' with different orientor emphasis. Since balanced attention to all basic orientors is crucial for viability, the set of orientors can be used to derive indicators that Facilitate comprehensive viability and sustainability assessments. The paper outlines the theoretical approach of 'orientation theory' and its application to the assessment and simulation of sustainable development issues. The formal approach of mapping indicators on basic orientors and assessing sustainability dynamics is illustrated using Worldwatch indicator time series. In an actor simulation this approach is used to successfully guide a small global model onto a sustainable path with high 'quality of life'. (C) 2000 Elsevier Science B.V. All rights reserved.
