Influence The Psychology
of Persuasion
Introduction
Robert B.
Cialdini, PH.D.
• Weapons of
Influence
• Reciprocation
• Commitment
and
Consistency
• Social Proof
• Liking
• Authority
• Scarcity
 What are the factors that cause a person to
say yes to another person?
 Which techniques most effectively use these
factors to bring about such compliance?
 Which psychological principles influence the
tendency to comply with a request?
•
→ Weapons of influence
Influence The Psychology
of Persuasion
Introduction
Robert B.
Cialdini, PH.D.
• Weapons of
Influence
 Research
•
• Reciprocation
• Commitment
and
Consistency
• Social Proof
•
Experimental work

Lab experiments

College students
Observation of compliance professionals

Sales operators

Fund-raisers

Recruiters

Advertisers

Others
• Liking
• Authority
• Scarcity
Influence The Psychology
of Persuasion
Introduction
Robert B.
Cialdini, PH.D.
 Six basic principles
• Weapons of
Influence
• Reciprocation
• Commitment
and
Consistency
• Social Proof
• Liking
• Authority
• Scarcity
•
Reciprocation
•
Commitment and consistency
•
Social Proof
•
Liking
•
Authority
•
Scarcity
 Rule of material self-interest
•
Most people want to get the most and pay the least
•
Very important in driving decisions, also a powerful
weapon
•
A given factor, deserves acknowledgement but not
extensive description
Influence The Psychology
of Persuasion
Robert B.
Cialdini, PH.D.
• Weapons of
Influence
• Reciprocation
• Commitment
and
Consistency
• Social Proof
• Liking
• Authority
• Scarcity
Ethology → the study of animals in their
natural settings
 Turkey mothers
•
Good mothers: loving, watchful, and protective
•
Virtually all this mothering is triggered by one thing:
the “cheap-cheap” sound of young turkey chicks
•
Stuffed polecat experiment


turkey natural enemy immediately attacked
stuffed polecat with hidden recorder that played the
“cheap-cheap” sound → no attack, but also was
gathered underneath by mother turkey
Influence The Psychology
of Persuasion
Robert B.
Cialdini, PH.D.
• Weapons of
Influence
• Reciprocation
• Commitment
and
Consistency
• Social Proof
Ethology → the study of animals in their
natural settings
 Fixed-action patterns
•
These responses are common
•
They can involve intricate sequences of behavior
 Two important things about fixed-action
patterns
• Liking
•
Work very well the majority of the time
• Authority
•
Humans also present fixed-action patterns
• Scarcity
Influence The Psychology
of Persuasion
Robert B.
Cialdini, PH.D.
Xerox machine experiment
(Ellen Langer – Havard social psychologist)
 People simply like to have reasons for what they do
• Weapons of
Influence
• Reciprocation
• Commitment
and
Consistency
• Social Proof
 Small favor of people waiting in line to use a library
copying machine
•

•
• Liking
• Authority
• Scarcity
1- “Excuse me, I have five pages. May I use the Xerox
machine because I’m in a rush?”
2- “Excuse me, I have five pages. May I use the Xerox
machine?”

•
94% let her skip ahead of them in the line
60% of positive response
3- “Excuse me, I have five pages. May I use the Xerox
machine because I have to make some copies?”

93% of positive response
 the word “because” triggered an automatic compliance
response → “because” = “cheap-cheap”
Influence The Psychology
of Persuasion
Automatic, stereotyped behavior
Robert B.
Cialdini, PH.D.
• Weapons of
Influence
• Reciprocation
• Commitment
and
Consistency
 Prevalent in much of human action
•
In many cases it is the most efficient form of behaving
•
In many other cases it is simply necessary
 Extraordinarily complicated stimulus environment,
rapidly moving and complex
• Social Proof
•
We need shortcuts
• Liking
•
We can’t be expected to recognize and analyze all the
aspects in each person, event and situation we
encounter in even one day
•
Not enough time, not enough energy, not enough
capacity
• Authority
• Scarcity
Influence The Psychology
of Persuasion
Automatic, stereotyped behavior
Robert B.
Cialdini, PH.D.
• Weapons of
Influence
• Reciprocation
• Commitment
and
Consistency
• Social Proof
• Liking
• Authority
• Scarcity
 Civilization advances by extending the
number of operations we can perform without
thinking about them
Alfred North Whitehead
(British philosopher)
Influence The Psychology
of Persuasion
Automatic, stereotyped behavior
Robert B.
Cialdini, PH.D.
• Weapons of
Influence
• Reciprocation
• Commitment
and
Consistency
• Social Proof
• Liking
• Authority
• Scarcity
 Most of us know very little about automatic
behavior patterns
 They make terrible vulnerable to anyone who
does know how they work
 Another glance to ethologist’s work → Mimics
•
animals that copy the trigger features of other
animals to makes them produce the automatic
response at the wrong time
Influence The Psychology
of Persuasion
Contrast Principle
Robert B.
Cialdini, PH.D.
• Weapons of
Influence
• Reciprocation
• Commitment
and
Consistency
• Social Proof
• Liking
 Objects’ weight
 Evaluation of blind dates
 Three pails of water
 Real life marketing
•
• Authority
• Scarcity
•
Retail clothiers

sell costly items first

show ugly items first
Real state
Influence The Psychology
of Persuasion
The old give and take … and take
Robert B.
Cialdini, PH.D.
• Weapons of
Influence
 The rule says → we would try to repay, in
kind, what another person has provided us
• Reciprocation
 “much obligated” = “thank you”
• Commitment
and
Consistency
 There is no human society that does not
• Social Proof
• Liking
• Authority
subscribe to the rule
 Web of indebtness → Human society
•
lowering of the natural inhibitions against
transactions
•
systems of aid, gift giving, defense, and trade
•
significant competitive advantage
• Scarcity
Influence The Psychology
of Persuasion
The old give and take … and take
Robert B.
Cialdini, PH.D.
• Weapons of
Influence
• Reciprocation
• Commitment
and
Consistency
 Social sanction to anyone who violates the
rule
•
moocher, ingrate, welsher
 There is an obligation to give, an obligation to
receive, and an obligation to repay
• Social Proof
• Liking
 The rule is over powering
• Authority
• Scarcity
 The rule enforces uninvited debts
 The rule can trigger unfair exchanges
Influence The Psychology
of Persuasion
The old give and take … and take
Robert B.
Cialdini, PH.D.
• Weapons of
Influence
• Reciprocation
• Commitment
and
Consistency
 Mexico and Ethiopia
•
1985 → 5.000 U$S relief donation
•
1935 → Mexico aided Ethiopia when invaded by Italy
 Prof. Denis Regan → Art appreciation experiment (coke
and raffle tickets)
• Social Proof
•
coke favor → more success in selling the raffle tickets
• Liking
•
coke favor → individuals bought twice as many tickets
• Authority
•
coke favor response → no relation with liking
•
coke U$S 0,10 → average raffle sale U$S 0,50
• Scarcity
Influence The Psychology
of Persuasion
The old give and take … and take
Robert B.
Cialdini, PH.D.
• Weapons of
Influence
• Reciprocation
• Commitment
and
Consistency
• Social Proof
 Christmas cards to a sample of perfect strangers
 The Hare Krishnas’ strategy
•
 Real life marketing
•
• Liking
• Authority
• Scarcity
flowers and books gifts
•
Free sample

expose the potential clients to the qualities of the product

but the beauty is that it is also a gift
Mailings including unsolicited gifts

double the response rates
Influence The Psychology
of Persuasion
Reciprocal Concessions
Robert B.
Cialdini, PH.D.
 Consequence of the rule or reciprocation → is an
• Weapons of
Influence
• Reciprocation
• Commitment
and
Consistency
• Social Proof
obligation to make a concession to someone who has
made a concession to us
•
Reasonability
•
Good faith
 County Youth Counseling experiment
•

• Liking
• Authority
• Scarcity
1st sample
•
ask them to chaperon a group of juvenile delinquents on a
day trip to the zoo → 17% accepted
2nd sample


ask them to spend 2 hours per week as a counselor to a
juvenile delinquent for a minimum of 2 years → 100%
refused
then, ask them to chaperon a group of juvenile delinquents
on a day trip to the zoo → 50% accepted
Influence The Psychology
of Persuasion
Reciprocal Concessions
Robert B.
Cialdini, PH.D.
• Weapons of
Influence
• Reciprocation
• Commitment
and
Consistency
• Social Proof
• Liking
• Authority
• Scarcity
 Rejection-then-retreat tactic
•
People don’t only agree to a desired request
•
but actually carry out the request
•
and finally to volunteer to perform further requests
 Positive by-products
•
felling a greater responsibility for, and satisfaction
with, the arrangement
Influence The Psychology
of Persuasion
Reciprocal Concessions
Robert B.
Cialdini, PH.D.
• Weapons of
Influence
 Real life marketing
•
• Reciprocation
• Commitment
and
Consistency
• Social Proof
• Liking
Rejection-then-retreat technique

Make a larger request/offer

After refuse make a smaller request/offer

•
Retail stores

• Authority
• Scarcity

•
Second request/offer does not have to be small it
has to be smaller than the initial one
Go up the line from U$S 350 → average sale U$S
550
Go down the line from U$S 3000→ average sale
U$S 1000
Request of referrals after refused sale
Influence The Psychology
of Persuasion
Commitment is the key
Robert B.
Cialdini, PH.D.
• Weapons of
Influence
• Reciprocation
• Commitment
and
Consistency
 The rule says → Once we have made a choice
or taken a stand, we will encounter personal
and interpersonal pressures to behave
consistently with that commitment
 This will cause us to respond in ways that
justify our earlier decision
• Social Proof
• Liking
• Authority
• Scarcity
 Even to do things that ordinarily we would not
want to do
 The person whose beliefs, words, and deeds
don’t match may be seen as → indecisive,
confused, two-faced, or even mentally ill
Influence The Psychology
of Persuasion
Commitment is the key
Robert B.
Cialdini, PH.D.
• Weapons of
Influence
 On the other side, high degree of consistency →
associated with personal and intellectual strength,
rationality, stability, and honesty
• Reciprocation
• Commitment
and
Consistency
• Social Proof
• Liking
• Authority
• Scarcity
 Consistency saves time, and effort, but sometimes it is
also a way of avoiding thing we would rather not realize
(shield again thought)
 Commitment has the potential to influence not only
future behavior, but also self-image
 Public and written commitments are stronger
 The more effort that goes into the commitment, the
greater is its power
Influence The Psychology
of Persuasion
Commitment is the key
Robert B.
Cialdini, PH.D.
 Racetrack
• Weapons of
Influence
•
• Reciprocation
• Commitment
and
Consistency
just after placing a bet, people is much more confident
of their horse’s chances of winning than they are
immediately before laying down that bet
 Staged thefts
•
onlookers would risk personal harm to halt the crime?
• Social Proof
•
no commitment → 4 of 20 persons reacted
• Liking
•
commitment → 19 of 20 persons reacted
• Authority
• Scarcity
 Prediction of future action
•
volunteer as a donation collector of the American
Cancer Association → when then actually asked to
volunteer 700% increase of positive responses
Influence The Psychology
of Persuasion
Commitment is the key
Robert B.
Cialdini, PH.D.
• Weapons of
Influence
• Reciprocation
• Commitment
and
Consistency
• Social Proof
• Liking
• Authority
• Scarcity
 Donations
•
→ “Hello, Mr. Smith. How are you feeling today?”
•
→ response: “Fine/good/very well”
•
→ standard solicitation approach
•
90% positive response against 18% with only the
standard solicitation approach
Influence The Psychology
of Persuasion
Commitment is the key
Robert B.
Cialdini, PH.D.
• Weapons of
Influence
 Korean War POWs
•
Prisoners Camps essay contests
• Reciprocation
• Commitment
and
Consistency
• Social Proof
• Liking
• Authority
• Scarcity
 Public-service billboard – “Drive Carefully”
•
83% refuse
•
76% acceptance
 Estimation of the length of a line experiment
 Initiation rites
Influence The Psychology
of Persuasion
Commitment is the key
Robert B.
Cialdini, PH.D.
• Weapons of
Influence
 Real life marketing
•
Toy manufacturers
• Reciprocation

• Commitment
and
Consistency

• Social Proof
• Liking
• Authority
• Scarcity
Sales slump after Christmas holiday season
The problem is not in motivating kids to want more toys
after Christmas, is in motivating the parents to buy them
– Special toy heavy pre-seasonal advertising
– Kids extract Christmas promises of their parents about the
special toy
– They undersupply the special toys
– Parents don’t have no other option → buy a different toy
– After Christmas advertising begins again to remind kids of
special toy
– Parents buy special toy to honor their promises
Influence The Psychology
of Persuasion
Commitment is the key
Robert B.
Cialdini, PH.D.
• Weapons of
Influence
 Real life marketing
•
• Reciprocation
• Commitment
and
Consistency
Industrial markets sale force

Start a large purchase by starting by a small one

Purpose is not profit, but commitment

No longer a prospect → a customer
• Social Proof
•
Establishing and communicating objectives
• Liking
•
Encouraging people to make public statements
• Authority
•
Cooling-off laws → have customers, rather than
the salesman, fill out the sales agreement
•
Testimonial contests → loyalty
•
Lowball → cause prospect to decide
• Scarcity
Influence The Psychology
of Persuasion
Truths are us
Robert B.
Cialdini, PH.D.
 One means we use to determine what is correct is to
• Weapons of
Influence
• Reciprocation
• Commitment
and
Consistency
• Social Proof
• Liking
• Authority
• Scarcity
find out what other people think is correct
 The greater number of people who find an idea correct,
the more the idea will be correct
 When we are unsure of ourselves, when the situation is
unclear, when uncertainty reigns, we are most likely to
look and accept the actions of others as correct
•
Pluralistic ignorance: everyone is looking to see what
everyone else is doing
•
Similarity: social proof operates most powerfully when
we observe people just like us
Influence The Psychology
of Persuasion
Truths are us
Robert B.
Cialdini, PH.D.
 Laugh Tracks
• Weapons of
Influence
 Bartenders “salt” their tip jars
• Reciprocation
 Children dog phobia
• Commitment
and
Consistency
• Social Proof
• Liking
• Authority
• Scarcity
•
treatment → watch videos of other kids playing with dogs
 Catherine Genovese murder (pluralistic ignorance)
•
failure of bystanders to aid a victim
•
38 bystanders – 35 minutes
•
better chance of receiving aid if there is only 1 bystander?
 Liking smoke experiment
•
75% of lone individuals reported it
•
38% of 3 person groups reported it
•
10% of 3 person groups with 2 syndicated
Influence The Psychology
of Persuasion
Truths are us
Robert B.
Cialdini, PH.D.
• Weapons of
Influence
• Reciprocation
 Lost wallets
•
33% of return when finder was dissimilar
•
70% of return when finder was similar
• Commitment
and
Consistency
 Jonestown
• Social Proof
 Applause
• Liking
• Authority
• Scarcity
 Real life marketing
•
Testimonial advertising
•
Creating long lines
•
Restaurants filling tables
Influence The Psychology
of Persuasion
The friendly thief
Robert B.
Cialdini, PH.D.
 We prefer to say yes to someone we know and like
• Weapons of
Influence
• Reciprocation
• Commitment
and
Consistency
• Social Proof
 Compliance factors:
•
similarity of opinion, life-style, background, personality
traits
•
familiarity and contact
•
cooperation in shared goals
•
physical attractiveness → favorable traits like talent,
kindness, honesty, and intelligence
•
compliments
•
association with positive things (beauty, what’s hip,
food)
•
success
•
smile
• Liking
• Authority
• Scarcity
Influence The Psychology
of Persuasion
The friendly thief
Robert B.
Cialdini, PH.D.
 Joe Girard
• Weapons of
Influence
• Reciprocation
• Commitment
and
Consistency
• Social Proof
•
5 car sales a day for 12 years
•
U$S 200.000 a year
•
Secret? “a fair price and someone they liked to buy
from”
 Real life marketing
•
• Liking
Tupperware parties

Reciprocation + Commitment + Social Proof + Liking
• Authority
•
Peer solicitation
• Scarcity
•
Good cop / bad cop
•
Eating together
•
Celebrity endorsements
Influence The Psychology
of Persuasion
Follow the expert
Robert B.
Cialdini, PH.D.
• Weapons of
Influence
• Reciprocation
• Commitment
and
Consistency
• Social Proof
• Liking
 We have a deep-seated sense of duty to
authority
 Tests demonstrate that adults will do extreme
things when instructed to do so by an
authority figure
 Milgram’s experiment
• Authority
•
60% went all the way
• Scarcity
•
0% stopped before 300V
Influence The Psychology
of Persuasion
Follow the expert
Robert B.
Cialdini, PH.D.
• Weapons of
Influence
• Reciprocation
• Commitment
and
Consistency
 Compliance factors:
•
Titles
•
Uniforms
•
Clothes
•
Trappings of status
• Social Proof
• Liking
• Authority
 Real life marketing
•
Scientific or medical endorsement
•
Uniforms
•
Hiring authority recognized individuals
• Scarcity
Influence The Psychology
of Persuasion
Scarcity
Robert B.
Cialdini, PH.D.
• Weapons of
Influence
• Reciprocation
• Commitment
and
Consistency
• Social Proof
• Liking
• Authority
• Scarcity
 Opportunities seem more valuable to us when
their availability is limited
 We want it even more when we are in
competition for it
 Potential loss plays an important role in
decision making
 Mormon church
•
exclusive areas
Influence The Psychology
of Persuasion
Scarcity
Robert B.
Cialdini, PH.D.
• Weapons of
Influence
• Reciprocation
• Commitment
and
Consistency
• Social Proof
 In fact, people seem to be more motivated by
•
the thought of losing something
•
than by the thought of gaining something of equal value
 Avoid potential loss vs. Obtain potential savings
 Things that are difficult to posses are typically better
than those that are easy to posses
• Liking
• Authority
• Scarcity
 As opportunities become less available, we loose
freedoms; and we hate to loose freedoms →
Psychological reactance
Influence The Psychology
of Persuasion
Scarcity
Robert B.
Cialdini, PH.D.
• Weapons of
Influence
 Psychological reactance
•
• Reciprocation
24 month old boys

• Commitment
and
Consistency

• Social Proof
• Liking
• Authority
• Scarcity
•
two toys, one behind a Plexiglas
two groups, one the Plexiglas to small to restrict
access to the toy, the other group the Plexiglas was
tall enough to restrict access to the toy

No restriction → no preference for either toy

Restriction → directly to the toy behind the Plexiglas
Teenagers

Romeo and Juliet effect
Influence The Psychology
of Persuasion
Scarcity
Robert B.
Cialdini, PH.D.
 The scarcity principle applies beyond material
• Weapons of
Influence
• Reciprocation
• Commitment
and
Consistency
• Social Proof
• Liking
• Authority
commodities → limited information value
 Reaction to censorship
•
approval or agreement with censored ideas or
arguments
 Beef importing company
•
One control group – standard sales presentation → X
sales
•
Group #2 - standard sales presentation + information of
scarcity in the upcoming months → X sales x 2
•
Group #3 - standard sales presentation + information of
scarcity in the upcoming months + information was
exclusive, not know by everyone → X sales x 6
• Scarcity
Influence The Psychology
of Persuasion
Scarcity
Robert B.
Cialdini, PH.D.
• Weapons of
Influence
 Cookies study
•
One group to taste a cookie from a jar with 10
cookies
•
Other group to taste the same cookie from a jar
with 2 cookies – This group rate the cookie
• Reciprocation
• Commitment
and
Consistency
• Social Proof

→ more desirable to eat
• Liking

→ more attractive as a consumer item
• Authority

→ more costly
• Scarcity
•
Recent scarcity
•
Scarcity because of competition for limited
resources
Influence The Psychology
of Persuasion
Scarcity
Robert B.
Cialdini, PH.D.
• Weapons of
Influence
 Real life marketing
•
Time limited offers – Now or never
•
Exclusive clients offers
•
Exclusive access areas
•
Limited quantity offers
•
Collector’s issues
• Authority
•
“If I’m not mistaken, it is the last one available”
• Scarcity
•
“I can make you another visit”
• Reciprocation
• Commitment
and
Consistency
• Social Proof
• Liking