Final answer:
Behaviors tend to be most resistant to extinction when the reinforcement is delivered intermittently (partial reinforcement).
Step-by-step explanation:
Behaviors tend to be most resistant to extinction when the reinforcement is delivered intermittently (partial reinforcement). In partial reinforcement, the person or animal does not get reinforced every time they perform the desired behavior. Among the reinforcement schedules, variable ratio is the most productive and the most resistant to extinction. Fixed interval is the least productive and the easiest to extinguish.