Which of the following is NOT one of Robert Cialdini's principles of persuasion?

Robert Cialdini's principles of persuasion are foundational concepts that describe how individuals can influence others effectively. Among these principles, reciprocity involves the idea that people feel obligated to return favors or kindnesses, creating a mutual exchange. Authority refers to the influence that comes from perceived expertise or power, whereby people are more likely to comply with requests from those they view as credible. Scarcity plays on the notion that people value what is rare or limited; when something is perceived as scarce, its desirability increases, prompting individuals to act quickly to obtain it.

In contrast, "predictability" is not recognized as one of Cialdini's principles. While predictability may pertain to the consistency of behavior or outcomes in various contexts, it does not directly relate to the mechanisms of influence and persuasion he outlined. Cialdini's work primarily focuses on the psychological drivers that motivate people to comply with requests or accept specific viewpoints, making reciprocity, authority, and scarcity integral to understanding these principles.