Final answer:
Punishment decreases behavior, while negative reinforcement increases behavior.
Step-by-step explanation:
The primary difference between punishment and negative reinforcement lies in their effect on behavior. Punishment always decreases a behavior, while negative reinforcement increases a behavior.
In punishment, an undesirable stimulus is added or presented to reduce a behavior, such as scolding a student for texting in class.
On the other hand, negative reinforcement involves removing an undesirable stimulus to increase a behavior, such as the seatbelt alarm stopping when you fasten your seatbelt.