Tolman introduced the notions of expectancy, of mental maps, into behaviorism. Rats and other animals did not simply respond to the number of rewards for each behavior, automatically repeating the most frequently rewarded behavior. Some kind of thought process mediated between stimulus and response. More specifically, the rats appeared to develop a set of expectations about how events would play out based on their prior experiences. They then made decisions by matching their expectations against information from the new situation. This kind of mental map is essentially identical to Piaget’s concept of mental schemas and has become a critical concept in many areas of psychology, including cognitive, developmental, and clinical psychology.