B. F. Skinner's reinforcement theory elaborated on which psychologist's law of effect?

• A. Pavlov
• B. Watson
• C. Hull
• D. Thorndike

Answer: (D)

The main idea being tested is how consequences shape future behavior. Thorndike’s law of effect stated that actions followed by satisfying outcomes become more likely to occur again, while those followed by unpleasant outcomes become less likely. B. F. Skinner took that insight and formalized it into operant conditioning, showing that behavior is strengthened or weakened by its consequences through reinforcement. He distinguished positive reinforcement (adding a pleasant consequence to increase the behavior) and negative reinforcement (removing an aversive condition to increase the behavior), and introduced how different reinforcement schedules influence the rate and pattern of responding. In essence, Skinner elaborated on Thorndike’s law by providing a precise mechanism—reinforcement—for how consequences shape behavior. The other options don’t fit because Pavlov’s work concerns classical conditioning with stimulus–response associations, Watson emphasizes observable behavior without the law-of-effect framework, and Hull integrates drive concepts into a different theoretical approach.