The Science of Persuasion
Seven Principles of Persuasion
Researchers have been studying the factors that influence us to say “Yes” to the requests of others for over 60 years. There can be no doubt that there’s a science to how we are persuaded, and a lot of the science is surprising.
When making a decision, it would be nice to think that people consider all the available information in order to guide their thinking. But the reality is very often different. In the increasingly overloaded lives we lead, more than ever we need shortcuts or rules of thumb to guide our decision-making.
My own research has identified seven of these shortcuts as universals that guide human behavior:
The First Universal Principle of Influence is Reciprocity
Simply put, people are obliged to give back to others the form of a behavior, gift, or service that they have received first.
If a friend invites you to their party, there’s an obligation for you to invite them to a future party you are hosting. If a colleague does you a favor, then you owe that colleague a favor. And in the context of a social obligation people are more likely to say yes to those who they owe.
One of the best demonstrations of the Principle of Reciprocity comes from a series of studies conducted in restaurants. So the last time you visited a restaurant, there’s a good chance that the waiter or waitress will have given you a gift. Probably about the same time that they bring your bill. A liqueur, perhaps, or a fortune cookie, or perhaps a simple mint.
So here’s the question. Does the giving of a mint have any influence over how much tip you’re going to leave them? Most people will say no. But that mint can make a surprising difference. In the study, giving diners a single mint at the end of their meal typically increased tips by around 3%.
Interestingly, if the gift is doubled and two mints are provided, tips don’t double. They quadruple—a 14% increase in tips. But perhaps most interesting of all is the fact that if the waiter provides one mint, starts to walk away from the table, but pauses, turns back and says, “For you nice people, here’s an extra mint,” tips go through the roof. A 23% increase, influenced not by what was given, but how it was given.
So the key to using the Principle of Reciprocity is to be the first to give and to ensure that what you give is personalized and unexpected.
The Second Universal Principle of Persuasion is Scarcity
Simply put, people want more of those things they can have less of.
When British Airways announced in 2003 that they would no longer be operating the twice daily London—New York Concorde flight because it had become uneconomical to run, sales the very next day took off.
Notice that nothing had changed about the Concorde itself. It certainly didn’t fly any faster, the service didn’t suddenly get better, and the airfare didn’t drop. It had simply become a scarce resource. And as a result, people wanted it more.
So when it comes to effectively persuading others using the Scarcity Principle, the science is clear. It’s not enough simply to tell people about the benefits they’ll gain if they choose your products and services. You’ll also need to point out what is unique about your proposition and what they stand to lose if they fail to consider your proposal.
The Next Principle is Consistency
People like to be consistent with the things they have previously said or done.
Consistency is activated by looking for, and asking for, small initial commitments that can be made. In one famous set of studies, researchers found rather unsurprisingly that very few people would be willing to erect an unsightly wooden board on their front lawn to support a Drive Safely campaign in their neighborhood.
However in a similar neighborhood close by, four times as many homeowners indicated that they would be willing to erect this unsightly billboard. Why? Because ten days previously, they had agreed to place a small postcard in the front window of their homes that signaled their support for a Drive Safely campaign. That small card was the initial commitment that led to a 400% increase in a much bigger but still consistent change.
So when seeking to influence using the consistency principle, the detective of influence looks for voluntary, active, and public commitments and ideally gets those commitments in writing.
For example, one recent study reduced missed appointments at health centers by 18% simply by asking the patients rather than the staff to write down appointment details on the future appointment card.
The Fifth Principle is the Principle of Liking
People prefer to say yes to those that they like.
But what causes one person to like another? Persuasion science tells us that there are three important factors. We like people who are similar to us, we like people who pay us compliments, and we like people who cooperate with us towards mutual goals.
As more and more of the interactions that we are having take place online, it might be worth asking whether these factors can be employed effectively in, let’s say, online negotiations.
In a series of negotiation studies carried out between MBA students at two well-known business schools, some groups were told, “Time is money. Get straight down to business.” In this group, around 55% were able to come to an agreement.
A second group however, was told, “Before you begin negotiating, exchange some personal information with each other. Identify a similarity you share in common then begin negotiating.” In this group, 90% of them were able to come to successful and agreeable outcomes that were typically worth 18% more to both parties.
So to harness this powerful principle of liking, be sure to look for areas of similarity that you share with others and genuine compliments you can give before you get down to business.