Dec 11, 2021

Intro to social proof

A few years ago, managers of a chain of restaurants in Beijing, China partnered with researchers to accomplish something decidedly profitable. They wanted to see if they could increase the purchase of certain menu items in a way that was effective yet costless. Their idea was to give the dish a certain label that would get customers to choose that item more frequently. Although they found a label that worked well, they were surprised it wasn’t what they thought would work previously, such as “Specialty of the house” or “Our chef’s recommendation for tonight.” Instead, the label that worked best was “most popular.” Sales of each dish with this label jumped from 13 to 20 percent. Quite simply, the dishes became more popular because of their popularity.

This anecdote illustrates another one of the 7 principles of persuasion from Robert Cialdini’s book Influence: The Psychology of Persuasion. The principle of social proof states that we determine what is correct by finding out what other people think is correct. As a result, advertisers love to inform us when a product is the “fastest growing” or “largest selling” because they don’t have to convince us directly that their product is good. They only need to show us that many others think so, which is a good enough shortcut for us to believe it too.

Certain nightclub owners manufacture a brand of visible social proof for their clubs’ quality by creating long waiting lines outside when there is plenty of room inside. Why are profiteers so ready to use social proof as a tactic? Sales and motivation consultant Cavett Robert captured the principle nicely in his advice to sales trainees: “Since 95 percent of the people are imitators and only 5 percent initiators, people are persuaded more by the actions of others than by any proof we can offer.” There are examples of this everywhere.

A Toyota dealership in Tulsa, Oklahoma was faced with the challenge of finding quality sales talent for their staff. They decided to run an ad on the radio that focused on the great demand for their vehicles, how many people were buying them, and, consequently, how they needed to expand their sales force to keep up. As they had hoped, they saw a significant jump in the number of applications to their sales team. Surprisingly, the biggest effect they saw however was an increase in customer floor traffic, an increase in sales in both the new and used vehicle departments, and a noticeable difference in the attitudes of customers. The unintended effect of expressing the demand they were experiencing to find more sales people caused more customers to want to buy from them.

The greater the number of people who find any idea correct, the more a given individual will perceive the idea to be correct. The principle of social proof says so. But there are certain conditions that can enhance this behavior. The optimizing conditions for social proof are when we are unsure of what is best to do (uncertainty); when the evidence of what is best to do comes from numerous others (the many); and when that evidence comes from people like us (similarity). I will discuss each of these optimizations in more detail in a future post.