THE SCIENCE OF
I hope you've enjoyed the
magazine so far. Now I'd like to let you in on something of great
importance to you personally. Have you ever been tricked into saying yes?
Ever felt trapped into buying something you didn't really want or
contributing to some suspicious-sounding cause? And have you ever wished
you understood why you acted in this way so that you could withstand these'
clever ploys in the future?
Yes? Then clearly this
article is just right for you. It contains valuable information on the most
powerful psychological pressures that get you to say yes to requests. And
it's chock-full of NEW, IMPROVED research showing exactly how and why these
techniques work. So don't delay, just settle in and get the information
that, after all, you've already agreed you want.
The scientific study of
the process of social influence has been under way for well over half a century,
beginning in earnest with the propaganda, public information and persuasion
programs of World War II. Since that time, numerous social scientists have
investigated the ways in which one individual can influence another's
attitudes and actions. For the past 30 years, I have participated in that
endeavor, concentrating primarily on the major factors that bring about a
specific form of behavior change-compliance with a request. Six basic
tendencies of human behavior come into play in generating a positive
response: reciprocation, consistency, social validation, liking, authority
and scarcity. As these six tendencies help to govern our business dealings,
our societal involvements and our personal relationships, knowledge of the
rules of persuasion can truly be thought of as empowerment.
When the Disabled American
Veterans organization mails out requests for contributions, the appeal
succeeds only about 18 percent of the time. But when the mailing includes a
set of free personalized address labels, the success rate almost doubles,
to 35 percent. To understand the effect of the unsolicited gift, we must
recognize the reach and power of an essential rule of human conduct: the
code of reciprocity.
All societies subscribe to
a norm that obligates individuals to repay in kind what they have received.
Evolutionary selection pressure has probably entrenched the behavior in
social animals such as ourselves. The demands of reciprocity begin to
explain the boost in donations to the veterans group. Receiving a
gift--unsolicited and perhaps even unwanted--convinced significant numbers
of potential donors to return the favor.
are far from alone in taking this approach: food stores offer free samples,
exterminators offer free in-home inspections, health clubs offer free
workouts. Customers are thus exposed to the product or service, but they
are also indebted. Consumers are not the only ones who fall under the sway
of reciprocity. Pharmaceutical companies spend millions of dollars every
year to support medical researchers and to provide gifts to individual
physicians--activities that may subtly influence researchers' findings and
physicians' recommendations. A 1998 study in the New England Journal of
Medicine found that only 37 percent of researchers who published
conclusions critical of the safety of calcium channel blockers had received
prior drug company support. Among researchers whose conclusions supported
the drugs' safety, however, the number of those who had received free
trips, research funding or employment skyrocketed--to 100 percent.
Reciprocity includes more
than gifts and favors; it also applies to concessions that people make to
one another. For example, assume that you reject my large request, and I
then make a concession to you by retreating to a smaller request. You may
very well then reciprocate with a concession of your own: agreement with my
lesser request. In the mid-1970s my colleagues and I conducted an
experiment that clearly illustrates the dynamics of reciprocal concessions.
We stopped a random sample of passersby on public walkways and asked if
they would volunteer to chaperone juvenile detention center inmates on a
day trip to the zoo. As expected, very few complied, only 17 percent.
For another random sample
of passersby, however, we began with an even larger request: to serve as an
unpaid counselor at the center for two hours per week for the next two
years. Everyone in this second sampling rejected the extreme appeal. At
that point we offered them a concession. "If you can't do that,"
we asked, "would you chaperone a group of juvenile detention center
inmates on a day trip to the zoo?" Our concession powerfully
stimulated return concessions. The compliance rate nearly tripled, to 50 percent,
compared with the straightforward zoo-trip request.
In 1998 Gordon Sinclair,
the owner of a well-known Chicago restaurant, was struggling with a problem
that afflicts all restaurateurs. Patrons frequently reserve a table but,
without notice, fail to appear. Sinclair solved the problem by asking his
receptionist to change two words of what she said to callers requesting
reservations. The change dropped his no-call, no-show rate from 30 to 10
The two words were
effective because they commissioned the force of another potent human
motivation: the desire to be, and to appear, consistent. The receptionist
merely modified her request from "Please call if you have to change
your plans" to "Will you please call if you have to change your
plans?" At that point, she politely paused and waited for a response.
The wait was pivotal because it induced customers to fill the pause with a
public commitment. And public commitments, even seemingly minor ones, direct
In another example, Joseph
Schwarzwald of Bar-Ilan
University in Israel and his co-workers nearly doubled monetary
contributions for the handicapped in certain neighborhoods. The key factor:
two weeks before asking for contributions, they got residents to sign a
petition supporting the handicapped, thus making a public commitment to
that same cause.
On a wintry morning in the
late 1960s, a man stopped on a busy New York City sidewalk and gazed skyward
for 60 seconds, at nothing in particular. He did so as part of an
experiment by City University of New York social psychologists Stanley
Milgram, Leonard Bickman and Lawrence Berkowitz
that was designed to find out what effect this action would have on
passersby. Most simply detoured or brushed by; 4 percent joined the man in
looking up. The experiment was then repeated with a slight change. With the
modification, large numbers of pedestrians were induced to come to a halt,
crowd together and peer upward.
The single alteration in
the experiment incorporated the phenomenon of social validation. One
fundamental way that we decide what to do in a situation is to look to what
others are doing or have done there. If many individuals have decided in
favor of a particular idea, we are more likely to follow, because we
perceive the idea to be more correct, more valid.
Milgram, Bickman and Berkowitz introduced the influence of
social validation into their street experiment simply by having five men
rather than one look up at nothing. With the larger initial set of upward
gazers, the percentage of New Yorkers who followed suit more than
quadrupled, to 18 percent. Bigger initial sets of planted up-lookers
generated an even greater response: a starter group of 15 led 40 percent of
passersby to join in, nearly stopping traffic within one minute.
Taking advantage of social
validation, requesters can stimulate our compliance by demonstrating (or
merely implying) that others just like us have already complied. For example,
a study found that a fund-raiser who showed homeowners a list of neighbors
who had donated to a local charity significantly increased the frequency of
contributions; the longer the list, the greater the effect. Marketers,
therefore, go out of their way to inform us when their product is the
largest-selling or fastest-growing of its kind, and television commercials
regularly depict crowds rushing to stores to acquire the advertised item.
Less obvious, however, are
the circumstances under which social validation can backfire to produce the
opposite of what a requester intends. An example is the understandable but
potentially misguided tendency of health educators to call attention to a
problem by depicting it as regrettably frequent. Information campaigns
stress that alcohol and drug use is intolerably high, that adolescent
suicide rates are alarming and that polluters are spoiling the environment.
Although the claims are both true and well intentioned, the creators of
these campaigns have missed something basic about the compliance process.
Within the statement "Look at all the people who are doing this
undesirable thing" lurks the powerful and undercutting message
"Look at all the people who are doing this undesirable thing."
Research shows that, as a consequence, many such programs boomerang,
generating even more of the undesirable behavior.
For instance, a suicide
intervention program administered to New Jersey teenagers informed them of
the high number of teenage suicides. Health researcher David Shaffer and
his colleagues at Columbia University found that participants became
significantly more likely to see suicide as a potential solution to their
problems. Of greater effectiveness are campaigns that honestly depict the
unwanted activity as damaging despite the fact that relatively few
individuals engage in it.
"rapport" and affectio all describe a
feeling of connection between people. But the simple word
"liking" most faithfully captures the concept and has become the
standard designation in the social science literature. People prefer to say
yes to those they like. Consider the worldwide success of the Tupperware
Corporation and its "home party" program. Through the in-home
demonstration get-together, the company arranges for its customers to buy
from a liked friend, the host, rather than from an unknown salesperson. So
favorable has been the effect on proceeds that, according to company liter-
ature, a Tupperware party begins somewhere in the
world every 2.7 seconds. In fact, 75 percent of all Tupperware parties
today occur outside the individ- ualistic U.S., in countries where group social bonding
is even more important than it is here.
Of course, most commercial
transactions take place beyond the homes of friends. Under these much more
typical circumstances, those who wish to commission the power of liking
employ tactics clustered around certain factors that research has shown to
Physical attractiveness can
be such a tool. In a 1993 study conducted by Peter H. Reingen
of Arizona State University and Jerome B. Kernan
of the University of Cincinnati, good-looking fund-raisers for the American
Heart Association generated nearly twice as many donations (42 versus 23
percent) as did other requesters. In the 1970s researchers Michael G. Efran and E.W.J. Patterson of the University of Toronto
found that voters in Canadian federal elections gave physically attractive
candidates several times as many votes as unattractive ones. Yet such
voters insisted that their choices would never be influenced by something
as superficial as appearance.
Similarity also can
expedite a rapport. Salespeople often search for, or outright fabricate, a
connection between themselves and their customers: "Well, no kidding,
you're from Minneapolis? I went to school in Minnes6ta!" Fundraisers
do the same, with good results. In 1994 psychologists R. Kelly Aune of the University of Hawaii at Manoa
and Michael D. Basil of the University of Denver reported research in which
solicitors canvassed a college campus asking for contributions to a
charity. When the phrase "I'm a student, too" was added to the
requests, donations more than doubled.
Compliments also stimulate
liking, and direct salespeople are trained in the use of praise. Indeed,
even inaccurate praise may be effective. Research at the University of
North Carolina at Chapel Hill found that compliments produced just as much
liking for the flatterer when they were untrue as when they were genuine.
Cooperation is another
factor that has been shown to enhance positive feelings and behavior.
Salespeople, for example, often strive to be perceived by their prospects
as cooperating partners. Automobile sales managers frequently cast
themselves as "villains" so the salesperson can "do
battle" on the customer's behalf. The gambit naturally leads to a
desirable form of liking by the customer for the salesperson, which
Recall the man who used
social validation to get large numbers of passersby to stop and stare at
the sky. He might achieve the opposite effect and spur stationary strangers
into motion by assuming the mantle of authority. In 1955 University of
Texas at Austin researchers Monroe Lefkowitz, Robert
R. Blake and Jane S. Mouton discovered that a man could increase by 350
percent the number of pedestrians who would follow him across the street
against the light by changing one simple thing. Instead of casual dress, he
donned markers of authority: a suit and tie.
Those touting their
experience, expertise or scientific credentials may be trying to harness
the power of authority: "Babies are our business, our only business,
.... Four out of five doctors recommend,'' and so on. (The author's
biography at the end of this article in part serves such a purpose.) There
is nothing wrong with such claims when they are real, because we usually
want the opinions of true authorities. Their insights help us choose
quickly and well.
The problem comes when we
are subjected to phony claims. If we fail to think, as is often the case
when confronted by authority symbols, we can easily be steered in the wrong
direction by ersatz experts--those who merely present the aura of
legitimacy. That Texas jaywalker in a suit and tie was no more an authority
on crossing the street than the rest of the pedestrians who nonetheless
followed him. A highly successful ad campaign in the 1970s featured actor
Robert Young proclaiming the health benefits of decaffeinated coffee. Young
seems to have been able to dispense this medical opinion effectively
because he represented, at the time, the nation's most famous physician.
That Marcus Welby, M.D., was only a character on
a TV show was less important than the appearance of authority.
While at Florida State
University in the 1970s, psychologist Stephen West noted an odd occurrence
after surveying students about the campus cafeteria cuisine: ratings of the
food rose significantly from the week before, even though there had been no
change in the menu, food quality or preparation. Instead the shift resulted
from an announcement that because of a fire, cafeteria meals would not be
available for several weeks.
This account highlights
the effect of perceived scarcity on human judgment. A great deal of
evidence shows that items and opportunities become more desirable to us as
they become less available. For this reason, marketers trumpet the unique
benefits or the one-of-a-kind character of their offerings. It is also for this
reason that they consistently engage in "limited time only"
promotions or put us into competition with one another using sales
campaigns based on "limited supply."
Less widely recognized is
that scarcity affects the value not only of commodities but of information
as well. Information that is exclusive is more persuasive. Take as evidence
the dissertation data of a former student of mine, Amram
Knishinsky, who owns a company that imports beef
into the U.S. and sells it to supermarkets. To examine the effects of
scarcity and exclusivity on compliance, he instructed his telephone
salespeople to call a randomly selected sample of customers and to make a
standard request of them to purchase beef. He also instructed the
salespeople to do the same with a second random sample of customers but to
add that a shortage of Australian beef was anticipated, which was true,
because of certain weather conditions there. The added information that
Australian beef was soon to be scarce more than doubled purchases.
Finally, he had his staff
call a third sample of customers, to tell them (1) about the impending
shortage of Australian beef and (2) that this information came from his
company's exclusive sources in the Australian National Weather Service.
These customers increased their orders by more than 600 percent. They were
influenced by a scarcity double whammy: not only was the beef scarce, but
the information that the beef was scarce was itself scarce.
I think it noteworthy that
many of the data presented in this article have come from studies of the
practices of persuasion professionals--the marketers, advertisers,
salespeople, fund-raisers and their comrades whose financial well-being
depends on their ability to get others to say yes. A kind of natural
selection operates on these people, as those who use unsuccessful tactics
soon go out of business. In contrast, those using procedures that work well
will survive, flourish and pass on these successful strategies [see "The
Power of Memes," by Susan Blackmore; SCIENTIFIC AMERICAN, October
2000]. Thus, over time, the most effective principles of social influence
will appear in the repertoires of long-standing persuasion professions. My
own work indicates that those principles embody the six fundamental human
tendencies examined in this article: reciprocation, consistency, social
validation, liking, authority and scarcity.
From an evolutionary point
of view, each of the behaviors presented would appear to have been selected
for in animals, such as ourselves, that must find the best ways to survive
while living in social groups. And in the vast majority of cases, these
principles counsel us correctly. It usually makes great sense to repay
favors, behave consistently, follow the lead of similar others, favor the
requests of those we like, heed legitimate authorities and value scarce
resources. Consequently, influence agents who use these principles honestly
do us a favor. If an advertising agency, for instance, focused an ad campaign
on the genuine weight of authoritative, scientific evidence favoring its
client's headache product, all the right people would profit--the agency,
the manufacturer and the audience. Not so, however, if the agency, finding
no particular scientific merit in the pain reliever, "smuggles"
the authority principle into the situation through ads featuring actors
wearing lab coats.
Are we then doomed to be
helplessly manipulated by these principles? No. By understanding persuasion
techniques, we can begin to recognize strategies and thus truly analyze
requests and offerings. Our task must be to hold persuasion professionals
accountable for the use of the six powerful motivators and to purchase
their products and services, support their political proposals or donate to
their causes only when they have acted truthfully in the process.
If we make this vital
distinction in our dealings with practitioners of the persuasive arts, we
will rarely allow ourselves be tricked into assent. Instead we will give
ourselves a much better option: to be informed into saying yes. Moreover,
as long as we apply the same distinction to our own attempts to influence
others, we can legitimately commission the six principles. In seeking to
persuade by pointing to the presence of genuine expertise, growing social
validation, pertinent commitments or real opportunities for cooperation,
and so on, we serve the interests of both parties and enhance the quality
of the social fabric in the bargain.
Surely, someone with your
splendid intellect can see the unique benefits of this article. And because
you look like a helpful person who would want to share such useful
information, let me make a request. Would you buy this issue of the
magazine for 10 of your friends? Well, if you can't do that, would you show
it to just one friend? Wait, don't answer yet. Because I genuinely like
you, I'm going to throw in--at absolutely no extra cost--a set of
references that you can consult to learn more about this little-known
Now, will you voice your
commitment to help? ... Please recognize that I am pausing politely here.
But while I'm waiting, I want you to feel totally assured that many others
just like you will certainly consent. And I love that shirt you're wearing.
By Robert B. Cialdini
Do the six key factors in the social influence process operate
similarly across national boundaries? Yes, but with a wrinkle. The citizens
of the world are human, after all, and susceptible to the fundamental
tendencies that characterize all members of our species. Cultural norms,
traditions and experiences can, however, modify the weight brought to bear
by each factor.
Consider the results of a report published this year by Stanford
University's Michael W. Morris, Joel M. Podolny and Sheira
Ariel, who studied employees of Citibank, a multinational financial
corporation. The researchers selected four societies for examination: the
U.S., China, Spain and Germany. They surveyed Citibank branches within each
country and measured employees' willingness to comply voluntarily with a
request from a co-worker for assistance with a task. Although multiple key
factors could come into play, the main reason employees felt obligated to
comply differed in the four nations. Each of these reasons incorporated a
different fundamental principle of social influence.
Employees in the U.S. took a reciprocation-based approach to the
decision to comply. They asked the question, "What has this person done
for me recently?" and felt obligated to volunteer if they owed the
requester a favor. Chinese employees responded primarily to authority, in
the form of loyalties to those of high status within their small group.
They asked, "Is this requester connected to someone in my unit,
especially someone who is high-ranking?" If the answer was yes, they
felt required to yield.
Spanish Citibank personnel based the decision mostly on
liking/friendship. They were willing to help on the basis of friendship
norms that encourage faithfulness to one's friends, regardless of position
or status. They asked, "Is this requester connected to my
friends?" If the answer was yes, they were especially likely to want
German employees were most compelled by consistency, offering
assistance in order to be consistent with the rules of the organization.
They decided whether to comply by asking, "According to official
regulations and categories, am I supposed to assist this requester?"
If the answer was yes, they felt a strong obligation to grant the request.
In sum, although all human societies seem to play by the same set of
influence rules, the weights assigned to the various rules can differ
across cultures. Persuasive appeals to audiences in distinct cultures need
to take such differences into account.
CIALDINI is Regents' Professor of Psychology at Arizona State University,
where he has also been named Distinguished Graduate Research Professor. He
has been elected president of the Society of Personality and Social
Psychology. Cialdini's book Influence, which was
the result of a three-year study of the reasons why people comply with
requests in everyday settings, has appeared in numerous editions and been
published in nine languages. He attributes his long-standing interest in
the intricacies of influence to the fact that he was raised in an entirely
Italian family, in a predominantly Polish neighborhood, in a historically
German city (Milwaukee), in an otherwise rural state.