CREDIBILITY
"ethos is the most potent of all means of
persuasion" (Aristotle, The Rhetoric,
1356a)
“To become a celebrity is to become a
brand name” (Phillip Roth)
What is Credibility?
Definition of credibility: "judgments made
by a perceiver (e.g., message recipient)
concerning the believability of a
communicator" (O'Keefe, 1995, pp. 130-
131)
A reliable generalization
“A highly credible source is
commonly found to induce more
persuasion toward the advocacy
than a low credibility source”
(Pornpitakpan, 2004)
“The generalization that high
credibility sources are more
influential than low credibility
sources is as close as one can come
to a universal law of persuasion”
(Gass & Seiter, 2007)
Celebrity endorsers: Selling
ethos
20% of all television
commercials feature a famous
person (Stevens & Rice,
1998)
Roughly 10% of advertising
expenditures go to pay the
endorser (Agrawal &
Kamakura, 1995)
Selling power is known as a
celebrity’s “quotient fare” or
simply “Q”
The match-up hypothesis
Endorsers are more
effective when there is a
"fit" between the endorser
and the endorsed product
Kamins, 1990.
The match-up hypothesis
How do these four endorsers fit the
“My Life, My Card” American
Express image?
Which brands go with which
endorsers?
What brands
would you match-
up with Katie
Couric, Amy
Winehouse, Big
Boi (Outkast),
and Steven
Spielberg?
More about celebrity endorsers
$800 million was spent in
the U.S. in 1998 on
spokespersons Thompson,
1998)
Reliance on celebrity
endorsers crosses all
product categories
(Thompson, 1998)
gender and celebrity
endorsers
Once relegated 2nd class
status, women endorsers
now lead the field
Are celebrity spokespersons
effective?
Study by Yankelovich and Gannett, of
1,000 consumers nationwide:
Only 25% of those questioned
said a TV ad would induce them
to try a product or brand
Only 3% said they would try a
new product based on the
recommendations of a celebrity
63% said they would try
something new based on the
advice of a friend.
But:
is what they say, what they
would actually do?
Even 3% of a national television
audience would represent millions
of viewers.
Celebrity endorsers: the
downside
Tarnished halos:
Martha Stewart (convicted of
lying about insider trading)
Mel Gibson (DUI and anti-
Semitic remarks
Tom Cruise (kooky behavior,
denigrated Brooke Shields for
taking anti-depressants)
Michael Richards (string of
racial epithets)
scandals produce negative
fallout for the sponsor's image
as well
increased use of animated and
animal endorsers can be
attributed, in part, to a fear of
endorser scandals hurting
business
Celebrities and politics
"There is no polling evidence
that celebrity endorsements
make a difference,“
• Kathleen Hall Jamieson
"political endorsements
generally have little impact on
voter preference."
• A 2007 study by the Pew
Research Center for the People &
the Press
It may be that celebrities are
more successful motivating
people to vote in general as
opposed to tendering a vote for
a specific candidate.”
• Natalie Wood, Ph.D., marketing
professor
Conceptualizing credibility
credibility as a receiver-
based construct
credibility as a multi-
dimensional construct
credibility as a
situational/contextual
construct
(McCroskey & Young, 1981)
what isn’t part of source
credibility?
physical attractiveness?
clothing?)
Credibility as a perceptual
phenomenon
Wilson (1968):
A guest speaker from Cambridge, England
was introduced to five different classes. His
status in the introduction varied:
• Student, Lecturer, Associate professor, Full
professor
After he left the room, the class was asked
to estimate his height.
With each increase in status, the perceived
height of the guest speaker increased ½
inch. The full professor was perceived as 2
½ inches taller than the student.
How credibility works
Petty & Cacioppo's ELM model
central route (cognitive processing,
deliberation, reflection)
peripheral route (credibility, appearance
factors, likeability)
“preferential” processing
role of involvement (familiarity with,
importance of issue)
Note: in Wilson & Sherrell's 1993) meta-
analysis, 8 of 12 credibility studies (67%)
supported the predictions of the ELM.
The factor analytic approach to
credibility
primary dimensions
expertise (competence)
trustworthiness (safety)
goodwill (perceived caring)
secondary dimensions
dynamism or extroversion
composure
sociability
inspiring
functional approach to credibility; dimensions
vary from situation to situation
expertise
Sources who are high in
expertise are generally
more persuasive than
sources who lack
expertise
High expertise sources
can advocate more
discrepant positions on
issues
Expertise may interact
with attractiveness,
gender, and perceived
similarity
trustworthiness
Jared Fogle, for
Subway, isn’t a
celebrity, but his
“plain folks” appeal
makes him
trustworthy.
Richard Hatch won
the million dollars
on Survivor, but is
he trustworthy?
Sources can be high in one
dimension and low in another
Simon Cowell may
have expertise,
but lack perceived
caring
Federal Reserve
Chairman Ben
Bernanke is high
in expertise but
low in dynamism
Amazing feats of credibility!
Bill Clinton, dissociation between the
man and the office:
Clinton’s job approval ratings remained at a
lofty 65% during the Monica Lewinsky
scandal while his personal popularity
plummeted to a dismal 35%.
A 30 point discrepancy in job approval Vs.
favorability ratings is unique in the history
of the presidency
Tiger Woods, defying the traditional
logic
Only a few celebrity superstars have been
able to successfully endorse multiple
products
Tiger Woods is on track to become the first
billion dollar endorser.
Moderating variables that
affect credibility
receiver involvement: credibility matters little if
receiver involvement is high
Low involved receivers are more susceptible to
credibility appeals
• reliance on peripheral processing
High involved listeners are less susceptible to
credibility appeals
• reliance on central processing
Authoritarianism
Authoritarians are highly susceptible to appeals by
admired sources
Timing of source identification
The source and the source’s qualifications must be
identified prior to the presentation of the message
Blind obedience: The power of
authorities
Stanley Milgram’s
(1974) classic
research:
Roughly 2/3s of the
subjects followed an
order to shock another
person repeatedly.
Hofling, Brotzman,
Dalrymple, Graves, &
Pierce (1966):
95% of nurses were
willing administer
potentially lethal doses
of “Astrogen”
Generalizing the credibility
construct
Credibility applies not
only to the rich and
famous
institutions and
organizations possess
credibility as well
In dyadic encounters;
there are two sources
whose credibility is at Do fictional
stake spokespersons
possess
credibility?
Institutional credibility: the
good, the bad, and the ugly
group entities concerned with
their image
Ronald McDonald House
NFL and United Way
tarnished corporate images
Enron and Anderson
Accounting
CIA and intelligence on WMD
Firestone tires
Texaco and Denny's racial bias
suits
Exxon Valdez oil spill
BATF and Ruby Ridge, Waco
incidents