Robert Cialdini
Professor of Psychology and Marketing, Arizona State University

How to Influence Others

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The psychologist of persuasion Robert Cialini on winning friends and influencing people.

Robert Cialdini

Robert Cialdini is president of Influence at Work, an international consulting, strategic planning and training organization. His books including, Influence: Science & Practice, are the results of more than 30 years of study into the reasons why people comply with requests in business settings. Cialdini received his Ph.D from the University of North Carolina and post doctoral training from Columbia University. He has held visiting scholar appointments at Ohio State University, the University of California, the Annenberg School of Communications, and the Graduate School of Business of Stanford University. Currently, he is a professor of marketing and psychology at Arizona State University, where he has also been named Distinguished Graduate Research Professor. In the field of influence and persuasion, Dr. Cialdini is the most cited living social psychologist in the world today.


Robert Cialdini: We can begin by talking about the book Influence [the subtitle of the books is: The Psychology of Persuasion], which resulted from my two and a half year program of research into the training programs of all of the different influence professions to see what they do to get us to say yes. I was surprised by one thing that I encountered in all of these programs. There were only six universal principles. Now, there were hundreds, maybe thousands of individual tactics, but only six universal principles of influence that seem to capture the great majority of what all of these individuals were doing.

Reciprocity. The desire of all of us to give back to someone who has given to us. So if an individual gives us something, a free sample, for example, we feel obligated to at least listen to what they have to say. At the supermarket, for example, that little lady with the cubes of cheese and meat, after you’ve eaten one of those, it’s very hard to just give her back the toothpick. You feel like you’re obligated to buy. Reciprocity is one.

Another is scarcity. The desire to have those things you can have less of, so things that are scarce, rare, dwindling in availability. One of the things that many organizations will do is to inform us of how rare, how uncommon their features are.

Another principle is commitment and consistency. The desire to be consistent with what we’ve already said or done, to be congruent with our internal values and what we’ve said that we’re going to do. So, for example, one study showed that if you call people on the phone, registered voters, and asked them if they will vote in the upcoming election, they, of course say yes. And they now vote, significantly more often than if they didn’t receive that phone call getting them to commit to that sort of thing.

Another principle is consensus or what we call, social proof. The idea that people want to follow the lead of similar others, people just like them. We’ve done a study, for example, in hotels. I don’t know how much you travel but when I do, in 70% of the hotels where I stayed, there’s a little laminated card asking me to reuse my towels and linen, right? We put different kinds of cards in rooms to see what we could say on the card that would most increase the likelihood that people would say yes. What hotels typically say is, “Do this for the environment. Do this for future generations. Or cooperate with us toward this common cause.” We added a different sign based on the principle of consensus that people want to do what everybody else is doing. It said, “The majority of guests who stayed at our hotel, do recycle their towels at least once.” That was absolutely true and it increased compliance by 28%. The interesting thing is, that was a completely costless message and it’s never ever been used in any hotel in any city that I visited, and the reason is those managers don’t know what the research says.

One of the hopes in these books that I’ve been publishing on the influence process is to allow people outside of the academic community, the non-researchers, who in any meaningful way have paid for this research with their tax dollars, to learn what we found out about them with their money. They’re entitled to know what we found out about them with their money. And so, that’s one of the purposes of the book, to be sure that we present this information to the wider public besides just the academic community in which the work was done.

Question: What was the thesis on your book “Yes”? [The subtitle of this book is: 50 Scientifically Proven Ways to be Persuasive.]

Robert Cialdini: We undertook the publication of the “Yes” book as a way to change the perception of persuasion as just an art, something that people are born with, with some sort of preternatural gift for saying the right thing at exactly the right time; and there are artisans of the persuasion process, no question about it. But it turns out persuasion is also a science. For over a half a century now, researchers in various kinds of situations, mostly psychologists, communication professionals, sometimes marketing professors in business schools, have been studying how you can say something in one particular way that will significantly increase the likelihood of assent to that thing, and have been checking their theories and their hypothesis in scientific experiments; lessons that we can provide to the larger community, beyond the scientific establishment, of how you can be more effective and how you can be confident that you will be more effective--because it’s grounded in true science, not just hunches and speculations of people who want to talk to you about this process.

Question: How does environment affect influence?

Robert Cialdini: What I’m going to claim about the principles that we talked about is that they are universals of influence. They’re so central to the human condition, so fundamental to the way we work as citizens of modern society that you will be able to use them successfully in all kinds of domains; with your friends, with your neighbors, with your co-workers, with your boss, even with that most resistant of all audiences, your children.

I’ll guarantee that these principles are so fundamental, they’re so psychologically central that they strum strings that are inside all of us and that we try to resonate with in order to behave correctly.

Question: What is the difference between influence and manipulation?

Robert Cialdini: The difference between influence and manipulation is an important and profound one.

Like dynamite, these principles, these tactics, these lessons can be used for good or ill. The difference is the extent to which they are employed by someone who’s taking a detective’s approach to the influence process, rather than a smuggler’s approach. A smuggler imports one or another of these principles into a situation where it doesn’t naturally exist.

Let’s say, for example, that we use the principle of authority. We can move people in our direction by claiming to be an expert on some topic that we’re talking about and if they believe us, it’s very human for them to want to take the shortcut route and follow what a legitimately constituted expert says. If we’re not an authority, we have exploited this process to bring people in, we’ve manipulated them and their interests and their outcomes. There’s a short-term success consequence of that, people do say yes to us. There’s a long-term disastrous consequence; that they don’t want to continue to deal with us if we fool them into yes.

On the other hand, if we’re a detective of influence, we go into a situation where we recognize that we are genuinely an authority. All we have to do is raise that to the surface and significantly increase the likelihood that people will be counseled correctly into a good choice to make.

So, for example, we did a study with hospital physical therapists. We just asked them to put on the wall of the physical therapy lab all of their credentials, all of their diplomas, all of their awards, and compliance with their exercise regimens went up 30% immediately. It’s not so surprising that people want to follow the lead of a legitimate authority. The interesting thing is that that was below the surface, the genuine authority. All that had to be done was that somebody--like a detective--saw it was there and brought it to the surface so it would be available to people to base their decisions on.

Question: Does understanding influence change your susceptibility to it?

Robert Cialdini: That’s a great question because it gets back to the question of ethics again, which is if somebody’s trying to influence me and I’ve read my book and I know that they’re trying, I should not be automatically resistant to that. I should only be resistant to the person who is trying to manipulate me into yes by claiming to be an authority when he or she isn’t. I do want to follow the person who is the genuine authority, for example. I do want to follow the person who gives me true information that what they are recommending is consistent with an existing commitment that I’ve already made a priority that I have in my life. Or I do want to be vulnerable to the appeals of someone who tells me about a genuinely unique or dwindling availability that has value to me. All of those things are influenced dimensions along which I want to move; except when they’re counterfeited.

The key is, if I’ve read about influence and I know about it, I should no longer be simply alert to the fact that somebody’s trying to influence me, it’s a more subtle differentiation. I need to be alert to the person who is trying to influence me with genuine information about the factors that steer me correctly; versus somebody who’s trying to fabricate that information.

Question: What qualities give something mass appeal?

Robert Cialdini: Yes, there are such features. So, for example, one of the principles of influence we talked about is liking. People prefer to say yes to those they know and like. And one of the factors that causes us to like somebody else is how similar we feel to that person. So the individual who, on a YouTube video, comes across as every person, as just like the audience to whom he or she is speaking, will get that liking, will get the rapport, will get the focus of attention and will make the information more likely to be considered.

The same thing goes with the authority principle that we’ve talked about. The extent to which you can appear more authoritative, more credible, more knowledgeable, and you can do that, for example, by doing something as simple as speaking slightly more rapidly than normal. We assign greater credibility and knowledge and confidence to people who speak slightly more rapidly than normal. If you speak too quickly, then you look like some salesperson who is trying to pull the wool over their eyes; but slightly more rapidly than normal, you get a sense this person knows what he or she is talking about, and you’re more willing to take that information in.

Topic: Explain your theory on littering.

Robert Cialdini: I’m not sure if you or your viewers would recall, but there is a public service announcement that was ran back in the ‘70s and ‘80s, called the Iron Eyes Cody Spot. That is reputed to be the single most effective public service announcement about the environment that has ever been sent to the American public. It showed a picture of a very stately, a buckskin-clad Native American paddling his canoe up a river that floated with various kinds of pollution. He came to the side of the river; the bank was covered with pollution. He came to the side of a road, also littered. A car went by and threw garbage out the window, a fast food bag, at his feet. It splattered. The camera panned up, and you saw a tear running down his face. Very powerful message: “Don’t litter.”

We have evidence that that message, not only may be less than optimal, it may actually be damaging to the goals of the creators of that ad because the subtext message was everybody’s littering. Everybody does this. And that is a more primitive message than this Native American actor doesn’t want you to litter.

And we’ve done studies to show that if somebody watches while someone else litters into an already littered environment, just as what happened in that Iron Eyes Cody spot, it significantly increases the likelihood that observers will litter there.

The thing you can do to decrease littering is to have someone litter into a pristine environment. That causes people to say, “Wait a minute! You are a norm breaker! I don’t want to be like you,” and they significantly suppress their tendency to litter as a consequence of seeing somebody litter into a clean environment.


Recorded on: Sep 15, 2008.