Influence: The Psychology of Persuasion

by Robert B. Cialdini

The principles—reciprocation, liking, social proof, authority, scarcity, commitment and consistency, and unity—are discussed both in terms of their function in society and in terms of how their enormous force can be commissioned by a compliance professional who deftly incorporates them into requests for purchases, donations, concessions, votes, or assent.

Research shows that messages are more likely to be successful if recipients can first be made to feel positively toward the messenger. Three of the seven principles of influence—reciprocation, liking, and unity—seem particularly appropriate to the task.

Successful joint efforts toward common goals steadily bridged the rift between the two groups.

the principle of social proof. This principle states that we determine what is correct by finding out what other people think is correct.