A stimulus change that decreases the future frequency of the behavior that immediately precedes it.

• A. Punisher
• B. Positive Reinforcement
• C. Positive Reinforcer
• D. Positive Punishment

Answer: (A)

A punisher is a stimulus change that, when it follows a response, decreases the likelihood of that response occurring again in the future. The statement matches this idea precisely: a stimulus change after the behavior reduces its future frequency. The general term punisher fits best because it covers any such decrease-inducing change, whether it involves adding an aversive stimulus or removing a reinforcing one.

Positive reinforcement and a positive reinforcer would increase the behavior, not decrease it, so they’re not correct. Positive punishment is a specific type of punishment that involves presenting an aversive stimulus after the behavior; while that would also reduce future occurrences, the question asks for the general term describing a stimulus change that decreases the behavior, which is best captured by punisher.