- Reciprocation. People are more willing to comply with requests (for favors, services, information, concessions, etc.) from those who have provided such things first.
- Commitment/Consistency. People are more willing to be moved in a particular direction if they see it as consistent with an existing commitment.
- Authority. People are more willing to follow the directions or recommendations of a communicator to whom they attribute relevant authority or expertise.
- Social Validation. People are more willing to take a recommended action if they see evidence that many others, especially similar others, are taking it.
- Scarcity. People find objects and opportunities more attractive to the degree that they are scarce, rare, or dwindling in availability.
- Liking/Friendship. People prefer to say yes to those they know and like.