After Billy's father began spanking him for using foul language, Billy use of foul language became more frequent. Which of the following processes best explains the change in Billy's behavior?

Negative reinforcement.

Explanation:

Reinforcement is a term that is commonly used in the area of Behavioral Psychology. Reinforcement can be simply defined as the act of trying to change, to reinforce a bad Behavior to a good one. There is positive reinforcement and negative reinforcement.

Positive reinforcement makes a bad Behavior to turn to a good behavior, while negative reinforcement at the end makes a bad Behavior still bad or even worse. An example if a negative reinforcement is that from the question. At the end of the spanking by the Father, Billy still use fowl language more frequently.