Final answer:
The key principle behind the social influence weapon of commitment and consistency is that people have a strong desire to remain consistent with their previous commitments and actions.
Step-by-step explanation:
The key principle behind the social influence weapon of commitment and consistency is that people have a strong desire to remain consistent with their previous commitments and actions. This principle states that once a person makes a choice or takes a stand, they will feel the need to behave in a way that is consistent with that previous commitment.
An example of how this weapon can be used in an unethical way is when a salesperson convinces a customer to make a small purchase or agree to a small commitment, and then later pressures them into buying a more expensive product or signing up for a long-term contract. In this situation, the salesperson takes advantage of the customer's desire to remain consistent and manipulates them into making a larger purchase that they may not have initially intended to make.