punishment

Meaning: In operant conditioning, punishment is a consequence that follows a behavior and makes that behavior less likely to be repeated. Positive punishment adds an aversive stimulus (a scolding after the behavior). Negative punishment removes a desired stimulus (taking away phone privileges). Here positive and negative mean add and remove, not good and bad. In sociology, the related idea is a negative sanction used in social control to discourage deviance.

On the MCAT: Passages describe a consequence and ask you to classify it. Ask two questions: was a stimulus added or removed, and did the behavior become less frequent? Punishment is often compared with reinforcement, including questions about effectiveness: it can suppress a behavior without teaching an alternative, it may produce fear of the punisher, and the behavior can return when the punishment stops.

Common confusion: Negative reinforcement is not punishment. Negative reinforcement removes an aversive stimulus and increases a behavior (buckling a seatbelt to stop the beeping). The fact that settles it: reinforcement increases a behavior and punishment decreases it, whatever is added or removed.