The concept of anticipations controlling behavior is introduced. Background is provided about the importance of anticipations from a psychological perspective. Based on the psychological background wrapped in a framework of anticipatory behavioral control, the anticipatory learning classifier system ACS2 is explained. ACS2 learns and generalizes on-line a predictive environmental model (a model that allows the prediction of future environmental states). The model is a subjective model, that is, no global state information is available to the agent. It is shown that ACS2 can simulate anticipatory learning processes and anticipatory controlled behavior by means of the model. The simulations of various rat experiments, previously conducted by Colwill and Rescorla, show that the incorporation of anticipations is indeed crucial for simulating the behavior observed in rats. Despite the simplicity of the tasks, we show that the observed behavior reaches beyond the capabilities of model-free reinforcement learning as well as model-based reinforcement learning without on-line generalization. Possible future impacts of anticipations in adaptive learning systems are outlined. |