They have been known for introduction conditioning models in behaviourism.
Explanation:
Behaviouralism is a scientific approach to study human and animal behavior and it assumes that behavior is a product of the interaction of various stimuli in the environment.
During the 20th century, John B. Watson developed methodological behaviorism and discarded the inspection methods to understand behavior by actions.
In the late 1930s, B.F Skinner suggested the method of covert behavior as emotional and cognition. This formed by the base for radical behaviorism.
Ivan Pavlov investigated how conditioning reflects respondent conditioning. Skinner gave the concept of operant conditioning.