Final answer:
Ed's behavior at work being predictable based on his greetings is an example of a stimulus control variable in operant conditioning, where environmental cues can influence behavior based on the history of reinforcement or punishment.
Step-by-step explanation:
Ed's boss reports that he can predict which days Ed is going to make a scene at work, based on how Ed greets everyone when he arrives. This indicates that a stimulus control variable is probably in effect. In psychology, especially in the context of operant conditioning, a stimulus control variable refers to an environmental cue that influences behavior. In this case, Ed's greeting serves as a predictor for his later behavior, which has likely been learned through a history of reinforcement or punishment following certain types of greetings.
In operant conditioning, behaviors are influenced by their consequences; behaviors followed by positive outcomes are likely to be repeated, while those followed by negative outcomes are less likely to be repeated. If Ed's past scenes at work have resulted in attention or a desired outcome, this could serve as reinforcement for future scenes, provided the initial greetings (or stimuli) are similar.