In an upscale food delivery chain, the delivery persons are given badges for timely food delivery at the end of each month. Bonus is given annually in exchange for six such badges. The company has therefore been able to retain most of its employees and get better returns year after year. Which behavioural technique is being used to reinforce delivery personnel?

The correct option is Token economy.

Explanation:
A token economy is a behavioral modification technique where targeted desirable behaviors are reinforced with tokens (such as points, badges, chips, or tallies). These tokens serve as secondary reinforcers that possess no inherent value on their own, but they can be collected and later exchanged for more valuable rewards, known as backup reinforcers (such as money, prizes, or special privileges).

In this scenario, the company reinforces the timely delivery behavior using this exact structure:
• Target Behavior: Timely food delivery by the delivery personnel.
• Tokens (Secondary Reinforcers): Badges awarded at the end of each month.
• Backup Reinforcer (Reward): The annual bonus, which is given only in exchange for a set number (six) of accumulated badges.

Here is why the other options are not correct:
• Negative reinforcement involves strengthening a behavior by removing or avoiding a negative or unpleasant stimulus. No unpleasant stimulus is being removed here.
• Differential reinforcement involves reinforcing one specific desired behavior while letting undesired behaviors go extinct (ignoring them). It does not involve accumulating tokens for a long-term reward.
• Modelling is a form of observational learning where individuals learn new behaviors by watching and mimicking a role model, which does not apply to this reward system.