Idea in Brief
The Challenge
People who are certain of their opinions are more likely to buy, buy sooner, and spend more; more willing to recommend products; and more apt to resist challenges to their beliefs. And yet the power of certainty as a tool of persuasion is largely overlooked in business.
The Solution
The authors identify four levers for increasing certainty: Consensus (perceiving that others share your opinion); repetition (expressing a position many times); ease (how readily an idea comes to mind); and defense (standing up for your beliefs).
In Practice
Companies should apply the certainty principles systematically: at the tactical level (for instance, in marketing programs and customer satisfaction surveys), as a managerial tool in interpersonal or team settings, and strategically (for instance, in negotiations with partners and other stakeholders).
Certainty profoundly shapes our behavior. The more certain we are of a belief—regardless of its objective correctness—the more durable it will be and the greater its influence on what we do. Across dozens of studies spanning more than two decades, consumer and social psychologists have shown that people who are certain of their beliefs are more likely to buy, buy sooner, and spend more. They’re more likely to sign petitions and to vote. They’re more willing to express their opinions, endorse products, advocate for causes, and try to persuade others to adopt their views. They’re better able to withstand attacks on their own beliefs and more inclined to challenge opponents.
