Transcript Slide 1

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Social Psychology
Attitude Change and Persuasion
October 14, 2008
Prof. Weiser
Curry College
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Introduction
• Persuasion
– Any instance in which a message induces change in attitude,
beliefs, or behavior
• Persuasion is most often attempted via some kind of
persuasive communication
– Written or spoken messages that advocate a certain product,
idea, or point of view
– Sometimes, however, a nice image of something can do the
trick
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What do you think it is that makes these
cigarette ads persuasive?
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What about these beer ads?
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Do you find these ads persuasive?
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Introduction
• During World War II, Carl Hovland and his colleagues
worked for the U.S. armed forces to increase the
morale of U.S soldiers. This is really how and when
scientific interest in persuasion began.
– They were interested in examining exactly what makes a
message persuasive
•
•
•
•
Communicator
Message content
Channel of communication
Audience
Carl Hovland
(1912-1961)
This approach to the study of persuasive communications is
known as the Yale Attitude Change Approach
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The Hurdles of the Persuasion Process
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Introduction
• Some of the most important research in persuasion
was conducted by social psychologists at Ohio State
University in the 1970s and 1980s
– This research emphasized that people’s thoughts in response
to persuasive messages matter a great deal in persuasion
– Called the cognitive response approach
• If a persuasive message triggers primarily favorable thoughts, then
persuasion will likely happen
• But, if a message triggers primarily unfavorable thoughts, no
persuasion will take place
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Central Route and Peripheral Route
• In the 1980s, two social psychologists from Ohio State
(Richard Petty and John Cacioppo) also assumed that
persuasion is likely to occur via one of two routes
Richard Petty
John Cacioppo
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Central Route and Peripheral Route
• Central route persuasion
– Occurs when people are motivated to cognitively focus on the arguments
of a persuasion message
• If those arguments are strong and compelling, favorable thoughts will follow,
and persuasion will take place
• If those arguments are weak, unfavorable thoughts will follow, and no
persuasion will take place
• Peripheral route persuasion
– Occurs when people are not motivated to think extensively about the
arguments of a persuasive message (because, for example, the message
is of little importance to them)
– In such cases, persuasion is triggered by peripheral cues (e.g., incidental
things like the speaker’s attractiveness, how fast the speaker talks, etc)
that are unrelated to the quality of the arguments in the message
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The Elements of Persuasion
•
To understand persuasion, one must consider: who
says what to whom, and how is it said?
•
Thus, when studying persuasion, we examine four
important factors:
1. The source
– Who presents the message?
2. The message
– What is in the message? How does it make people feel?
3. How the message is communicated
– What is the modality of the message?
4. The audience
•
Who will receive the message?
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Four Factors of Persuasion
Source
Message
Modality
Audience
Are they
trustworthy? Do
they have
expertise? Are
they trustworthy?
Attractive?
Does in induce
positive feelings?
negative feelings?
Is it one or twosided? How
discrepant?
Is it one to one?
Is it a personal
one? Is it on
radio, TV, or
print?
Who is the
message aimed
at? How old are
they? What are
they thinking?
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Source Factors
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Source Factors
1. Credibility
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Credible speakers (i.e., those who are perceived to have
high levels of expertise and trustworthiness) are more
persuasive than speakers who lack credibility
– Bochner & Insko (1965)
•
•
Speaker claims that only 4 hrs of sleep per night is necessary
The message was more persuasive if the speaker was thought to be a
renowned scientist (vs. YMCA gym teacher)
– Walster & Festinger (1962)
•
•
Students eavesdrop on graduate students’ conversation about campus
regulations
The eavesdroppers were more influenced by the speakers if they
thought the speakers were unaware that they were being listened to
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Credibility
• Another factor in credibility is if a speaker adopts a
position that we do not expect them to (argues against
their own self-interest)
– Eagly, Wood, & Chaiken (1978)
• Students listen to speaker give pro-environmental speech (i.e.,
attacking a factory’s pollution of a river)
• The seaker was more effective if thought to have a pro-business
background (in which he would be arguing against his own selfinterest) than if thought to have an environmental background
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Credibility
• It has been found that perceived credibility increases
when people talk fast
– Miller, Maruyama, Beaber, & Vallone (1976)
• People who listened to tape-recorded message rated fast speakers
(190 words-per-minute) as more intelligent, knowledgeable, and
persuasive than slower speakers (110 wpm).
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Source Factors
2. Physical attractiveness
•
Physically attractive communicators are more persuasive
than less attractive communicators
– Chaiken (1979)
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•
•
Students tried to get as many signatures on a “veggie food” petition as
they could
Physically attractive students tended to get more signatures
But, these attractive students tended to have higher GPAs and SAT
scores, and thus were more skilled; maybe due to self-fulfilling prophecy?
– Dion & Stein (1978)
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Pretty 10-12 year-old girls (compared to less pretty girls of same age)
were more persuasive at getting similar-aged boys to eat bitter-tasting
crackers
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Source Factors
3. Similarity
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Message recipients are more influenced by communicators
who are similar to them than by communicators who are
dissimilar
– Brock (1965)
The paint store study
•
A paint store salesperson approached customers waiting to in line to buy
paint to try to persuade them to buy a different brand
•
In some cases, the salesperson claimed to have purchased 40 gallons
of the paint the shopper was buying (thus making the salesperson look
like an expert --- dissimilar)
•
In other cases, the salesperson claimed to have tried the paint once and
recommended a different brand (thus making him sound like an
everyday person like the shopper was ---similar)
•
Shoppers were more likely to switch paints if the salesperson appeared
similar to them than if the salesperson appeared dissimilar
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Source Factors
• Sometimes, however, the impact of a non-credible
communicator may actually increase over time
– This happens, presumably, because people sometimes
remember the message, but forget the fact that it was
delivered by a non-credible speaker or why they discounted
the message
– This delayed persuasion, after people forget who
communicated a message, is called the sleeper effect.
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Message Factors
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Message Factors
1. Positive feelings
•
Messages become more persuasive if they become
associated with positive feelings
– Janis, Kaye, & Kirschner (1965)
•
People who snacked on peanuts and Pepsi were more persuaded by
various messages than those who did not snack while reading these
messages
– Hendrick & Galizio (1972)
•
•
Students more persuaded by messages accompanied by pleasant guitar
music than without music
Thus, if you can’t make a strong case, put audience in a
good mood and hope that they’ll feel good about the
message without thinking too much about it.
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Janis, Kaye, & Kirschner (1965)
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Message Factors
2. Messages that arouse fear (fear appeals)
•
Idea here is that messages that scare people into doing
certain things (e.g., exercising) or not doing certain things
(e.g., smoking) can be very persuasive.
•
But, the question is, how much fear is enough?
– Janis & Feshback (1953) The dental hygiene experiments
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•
•
High school students presented with three types of messages designed
to get them to brush their teeth more often
The messages induced either low, medium, or high fear
Strangely, the messages that induced low fear were the most effective at
getting the students to improve their tooth-brushing habits!
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Janis & Feshbach (1953)
% changing behavior
40%
35%
30%
25%
20%
15%
10%
5%
0%
Control
High
Medium
Fear Condition
Low
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Message Factors
• Janis & Feshback believed that the high fear messages caused
the student to become defensive and thus deny the importance
of the threat.
• Fear-arousing messages are more effective if they not only
scare people, but also are presented in a way that allow to
perceive a solution and make people feel capable of
implementing it.
• Leventhal, Watts, & Pagano (1967)
– Three groups of smokers get persuasive message on dangers of smoking
• Scary film only
• Informational pamplet
• Scary film + informational pamphlet
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Avg. Number of Cigs Smoked Per
Day
Leventhal, Watts, & Pagano (1967)
120
100
80
Film alone
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Film + instructions
Instructions only
40
20
0
Before
experiment
1 week
2 weeks
1 month
Time after experiment
3 months
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Message Factors
3. Message discrepancy
•
Are messages that argue extreme positions (i.e., those that
are highly discrepant from someone’s attitude) persuasive?
•
They can be, but generally only if they are delivered by a
highly credible source
– Aronson, Turner, & Carlsmith (1963) The T.S. Elliot study
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Students read (and disliked) a poorly-written poem
•
Some of the students read a evaluation of the poem by a credible source
(T.S. Elliot, a famous writer), and some read an evaluation from a lowcredible nobody (“Agnes Stearns”)
•
The evaluation was either slightly, moderately, or strongly favorable
(which meant, respectively, that the discrepancy between how the
students felt and the evaluation was small, medium, or large)
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Aronson, Turner, & Carlsmith (1963)
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Message Factors
4. One versus two-sided messages
•
A one-sided message only presents one side of an argument
(e.g., why you should or should not do something)
•
A two-sided message consists of the argument, plus an
opposing counterarguments
– Werner, Stoll, Birch, & White (2002)
•
•
Aluminum can study
Two-sided message doubled recycling efforts
– Hovland, Lumsdaine, & Sheffield (1949)
•
•
One versus two-sided message that the WWII would last 2 more years
One-sided message was most persuasive for those who initially agreed
with the content of message, whereas two-sided message was more
effect for those who were initially skeptical of the content of the message
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Hovland, Lumsdaine, & Sheffield (1949)
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Inoculation Theory
• Later research showed that people given 2-sided
messages become more resistant to counterpersuasion. This is called an “inoculation effect” and
led to development of Inoculation Theory.
• Inoculation Theory (McGuire, 1964)
– Exposure to weak attacks (counterattacks) on our attitudes
can actually make them stronger. This is because such weak
attacks act like inoculations.
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Inoculation Theory
• McGuire & Papageorgis (1961)
– Present subjects with “cultural truisms”
• e.g., “It is important to brush your teeth after every meal”
• “Mental disorders are not contagious”
– Then, subject either thinks of 2 opposing arguments and refutes them
(inoculation condition), or simply lists 2 supporting arguments (supportive
defense). Later, the truisms are attacked.
Treatment
Mean Belief Level
Innoculation + Attack
10.33
Supportive Defense + Attack
7.39
Attack Only
6.64
15.00 indicates complete agreement with the truism, whereas 1.00 indicates complete
disagreement. Lower scores indicate more attitude change after the attack.
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Innoculation Theory
• McAlister (1980)
– High school students inoculated
junior high kids against peer
pressure to smoke
• They were taught to refute slogans
that extolled the virtues of smoking
• Also, they role-played refuting peer
pressure to smoke
• Compared to a junior high in which
the kids were not inoculated, the
inoculated kids had lower smoking
rates later one
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Modality Factors
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Modality Factors
• Eldersveld & Dodge (1954)
– Political persuasion in Ann Arbor Michigan
• Media only = 19%
• Four mailings = 45%
• Visited personally and given face-to-face appeal = 75%
• Maccoby (1980)
– Studied the effectiveness of three types of message
modalities on reducing heart attacks in 3 California towns
• Regular media
• Two year media onslaught (TV, newspapers, radio, mailers)
• Media onslaught plus personal visits and eduation
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Maccoby (1980)
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Media Influence
• Two-step flow of communication (Katz, 1957)
– Media influences regular people in an indirect way
• First, it influences many opinion leaders (that is, those who regular
folks perceive as experts)
– These include talk show hosts, editorial writers, doctors, teachers,
professors, scientists, newspaper and magazine editors, etc
• These perceived experts, in turn, influence regular folks
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Comparing Media
• Chaiken & Eagly (1976)
– Examined what modality in which persuasive messages would lead to the
most attitude change. It depended on the complexity of the message.
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Audience Factors
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Audience Factors
1. Age
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People tend to have different social and political attitudes
depending on their age
•
•
For example, older people tend to me more conservative than
younger people
This seems to be mainly because of generational effects
– People tend to maintain the attitudes they developed when they were
young
– It does not really seem to be the case the attitudes change as we
grow older (life-cycle effects)
– e.g., Newcomb (1943) Bennington College Study
– Liberal attitudes persisted many decades later
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Audience Factors
2. Gender
•
Hundreds of experiments have shown that women are more
easily persuaded than are men
•
•
•
This could be because women are typically socialized to be more
cooperative than men
Thus, they likely regard conformity as a positive trait
However, some studies suggest that it depends on the
subject of the message
•
Eagly & Carli (1983)
•
Men and women are more likely to be persuaded on topics that they
know little about, but both are less likely to be persuaded on topics that
they know a good deal about
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Audience Factors
3. What the audience is thinking
•
The thoughts that are going through the mind of an audience
are crucial to understanding persuasion. What we think during
or in response to a message is crucial to persuasion.
•
One example of this has to do with forewarning (i.e., knowing
that you are about to be subjected to a persuasive message)
– Freedman & Sears (1965)
•
•
California students who were forewarned that they would hear a talk about
why they should not drive at night were not at all persuaded by this talk
(compared to those who had not been forewarned)
Forewarned is forearmed!!
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Forewarning
• Why does forewarning prevent attitude change?
– Petty & Cacioppo (1977)
• They suggested that the reason is because forewarning causes us to
mentally come up with counterarguments to refute the persuasive
attempt
• To test this, college freshman in an experiment were either warned or
not warned that, in a few minutes, they were going to hear a talk on
“Why college sophomores should be required to live in the dorms”
• These students were asked (before hearing the talk) to do one of two
things:
– Write down all their general thoughts about anything
– Write down all their thoughts about the idea of sophomores having to
live in the dorms
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Petty & Cacioppo (1977)
Unwarned
Forewarned
General
Thought
Topic
Thoughts
General
Thoughts
Topic
Thoughts
Attitude Change
6.27
4.00
3.47
4.20
Counterarguments
0.00
2.67
2.22
3.46
Subjects who were forewarned mentally came up with more
counterarguments. This seems to be the reason for why they
exhibited less attitude change. Therefore, it seems that forewarning
increases negative counterarguments (sort of like inoculation) and
prevents likelihood of attitude change.
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Distraction
• If we are somehow unable to think about the content of
a persuasive message (if we become, for example,
distracted), then we will be unable to come up with
counterarguments
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Distraction
• In such situations, we will be more susceptible to
persuasion
– This will occur for messages with weak arguments
• In addition, messages with strong arguments will be
less persuasive
– Because we are unable to come up with favorable thoughts
about the message
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Distraction
• Petty, Wells, & Brock (1976)
– Students presented with a persuasive message regarding why
a tuition increase is necessary
• Some of the students were presented with a version of the message in
which the arguments were strong
– e.g., “The money would allow us to hire more and better-quality faculty,
thereby reducing class size”
• Some of the students were presented with a version in which the
arguments were weak
– e.g., “The money would allow us to hire more gardeners to keep the
ornamental shrubs looking nice”
• In addition, some of the students were distracted when they listened to
the message (by performing a complex computer task), whereas others
were not
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Petty, Wells, & Brock (1976)
Level of
Support
for
Message
Distraction Level
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Elaboration Likelihood Model of Persuasion
(Petty & Cacioppo, 1981)
• Based on the research just reviewed, Petty & Cacioppo
developed the Elaboration Likelihood Model (ELM)
in the early 1980s
• The key concepts of the ELM include:
– Central route
– Peripheral route
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Elaboration Likelihood Model of Persuasion
• Central route persuasion depends upon being motivated and able
to think about the message content
– If so, only strong arguments will lead to lasting attitude change; factors
that are inconsequential to argument quality (e.g., source credibility) will
matter little
– Argument quality is said to be a central route cue
• Peripheral route persuasion is more likely to occur when a message
recipient is neither able nor motivated to think about the
arguments in a message
– In such cases, argument quality makes no difference at all
– Only factors that are peripheral to the message (e.g., speaker attractiveness,
mood, number of arguments, source credibility, etc), called peripheral cues,
will influence whether or not the message recipient is persuaded
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Prototypical ELM Study
• Petty, Cacioppo, & Goldman (1981)
– College students receive a persuasive message regarding
mandatory comprehensive exams for graduating seniors
– Some are told that it could happen next year (high relevance),
others told it would not happen for 10 years (low relevance)
– The message contained either strong or weak arguments
• Strong arguments: based on statistics, hard data, etc
• Weak arguments: personal opinions, single examples, etc
– Also, subjects were told that either:
• the message was based on a report from a renowned Princeton
professor (high expertise), or,
• The message was based on a report from a local high school class (low
expertise)
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Petty, Cacioppo, &
Goldman (1981)
When subjects were motivated to
think about the message (i.e., high
relevance), only argument quality
had any effect in changing attitudes.
Source expertise had little effect.
However, when subjects were not
motivated to cognitively scrutinize
the message (low relevance),
argument quality did not have much
of an effect. Source expertise (a
peripheral cue) did have an effect.
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Another Prototypical ELM Study
• Petty & Cacioppo (1984)
– College students get the same “mandatory comprehensive
exams for seniors” persuasive message as earlier
– Some are told that it could happen next year (high relevance),
others told it would not happen for 10 years (low relevance)
– The message again contained either strong or weak arguments
– Also, the message contained either 9 arguments (some strong,
some weak) or only 3 arguments (all strong or weak)
• The number of arguments in a message is a peripheral cue, and
presumably will have little effect under conditions in which the subject is
motivated to cognitive scrutinize the arguments of the message. But, it
should have an effect under the low relevance condition.
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Petty & Cacioppo (1984)
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Elaboration Likelihood Model
• When someone is motivated and able to cognitively
scrutinize the arguments in a persuasive message
(e.g., when the message is highly relevant), peripheral
cues can sometimes have an additive or subtractive
effect on persuasion
– This means that peripheral cues can bias the processing
of a message in a positive or negative way
– This is most likely to happen when the arguments in a
persuasive message are ambiguous. Under such conditions:
• “Strong” peripheral cue (e.g., highly credible source) = even more
attitude change
• “Weak” peripheral cue (e.g., low credible source) = even less attitude
change
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Elaboration Likelihood Model
• Chaiken & Maheswaran (1994)
• Subjects received a persuasive message about new product, the “XT100” telephone answering machine
• Some of the subjects were told that it would soon be marketed in their
locale (high relevance), whereas other told that it would be marketed in a
distant locale (low relevance)
• Also, some were told that the product description they would read had
either appeared in Consumer Reports (high credibility report) or had
been prepared for a Kmart pamphlet (low credibility report)
• Subjects then read one of three messages (product descriptions) that
compared XT-100 to competing brands (argument quality)
– Unambiguous strong
– Unambiguous weak
– Ambiguous
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Chaiken &
Maheswaran (1994)
In the low relevance condition,
source credibility affected
attitudes, but argument quality
did not.
In the high relevance condition,
strong arguments were more
effective than weak arguments.
However, a peripheral cue
(source credibility) biased the
processing of ambiguous
arguments in a positive or
negative way, depending on
whether the source was low
or high in credibility.
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Next time: Conformity and Obedience
(Chapter 6)