Table 1.

Summary of Cialdini Principles of Persuasion.

Principle	Description
Liking	The act of saying yes to something you know and like; for example, a social engineer presenting himself as helpful and empathetic toward the victim in a password reset process.
Reciprocity	Repaying an earlier action in kind; for example, conveying to a victim that they have detected suspicious activities in the victim's credit card account while encouraging the victim to reset the password with their assistance.
Social Proof	The use of endorsement; for example, stating that, due to recent suspicious activities, new security requirements are issued and must be complied by all account holders.
Consistency	Leveraging the desire of individuals to be consistent with their words, belief, and actions; for example, reminding users that they have to comply with a password reset policy as they have previously done.
Authority	Responding to others with more experience, knowledge, or power; for example, an email signed by a Senior Vice President of a bank requesting customers to reset their account passwords.
Scarcity	Something being valuable when it is perceived to be rare or available for a limited time; for example, giving a user 24-h notice before they deactivate the user's account.
Unity	Shared identity between the influencer and the influenced

The principle of Unity was introduced in Cialdini (2016) but has not been studied in social engineering research; it is presented here for the purpose of completeness.