Another form of consistency theory is Cognitive Dissonance
Theory, developed by Leon Festinger
(1957). Festinger argues
that there are three possible relationships among cognitions
(thoughts, ideas): consonance, dissonance, and irrelevance.
Two ideas that are consistent, like “I like Michael
Jordan” and “Michael Jordan is the greatest basketball
player ever,” are consonant. Two thoughts that are
inconsistent, like “I smoke cigarettes,” and “Cigarettes
can kill smokers,” are dissonant. Two cognitions that
are unconnected, like “Michael Jordan is the greatest
basketball player ever” and “Cigarettes can kill
smokers,” are irrelevant. Dissonance Theory declares
that dissonance is an unpleasant motivating state (a feeling)
that encourages attitude change to achieve or restore
consonance. So far, Dissonance Theory is similar to Balance
Theory. It is somewhat like the assumptions of Congruity
Theory, except that Dissonance is not limited to situations in
which a Source makes an Assertion about an attitude Object.
Dissonance theory has been refined in later work (Aronson,
1969; Brehm & Cohen,
1964; Wicklund &
One of the advantages of Dissonance Theory is that it can
consider more than two cognitions at a time. Another advantage
is that it acknowledges that some cognitions are more
important than others, and that the importance of cognitions
influences the amount of dissonance. Specifically, Dissonance
Theory predicts that the amount of dissonance is influenced by
two factors: (1) the proportion of dissonant and consonant
cognitions and (2) the importance of the cognitions.
For example, if I know four bad things and six good things
about my friend Bob, I should experience more dissonance than
if I know one bad thing and six good things. In the example
below, think about how much dissonance would exist if I had
all four of the dissonant thoughts versus if I only had one of
these cognitions. It makes sense that the more inconsistent
thoughts I have, the more dissonance I should experience.
Cognitions about Bob
C1 Bob is funny.
C2 Bob likes basketball (like me).
C3 Bob likes rock and roll music (like me).
C4 Bob is a loyal friend.
C5 Bob likes the action/adventure movies (like me).
C6 Bob helped me with algebra in High School.
D1 Bob doesn’t like my brother.
D2 Bob likes those stupid horror movies (unlike me).
D3 Bob is really messy.
D4 Bob sometimes goes too far in making fun of people.
Furthermore, the importance of these good and bad thoughts
makes a difference. If my brother is really important to me,
the first dissonant thought, that Bob doesn’t like my
brother (D1), could create a lot of dissonance. On the other
hand, if I am not close to my brother, this cognition won’t
bother me as much. Thus, dissonance theory considers all of
the relevant thoughts at once, considering both the proportion
of consistent (consonant) and inconsistent (dissonant)
thoughts and the importance of those thoughts. Balance Theory
and Congruity Theory can consider only one idea and neither
theory accounts for the importance of ideas.
Dissonance theory suggests that there are three ways to
restore consonance. First, one may change a cognition to
reduce dissonance. If I had new information which suggested
that Bob really liked my brother, then my idea that Bob
doesn’t like my brother (D1) could change (into C7, Bob
likes my brother). This should reduce my dissonance about Bob.
Second, a person who experiences dissonance can add a new
cognition. For example, I could decide that Bob just doesn’t
know my brother very well, and that if Bob got to know him,
Bob’s feeling toward my brother would almost certainly
change. The third way to reduce dissonance is to change the
importance of cognitions. I could decide that because Bob
hardly ever sees my brother, I could reduce the importance of
Bob’s feeling toward my brother, which would reduce my
dissonance. One important limitation of Dissonance Theory
(unlike Congruity Theory, for example) is that Cognitive
Dissonance does not predict how dissonance will be
reduced in any situation.
An obvious implication of Cognitive Dissonance Theory is that
if you want to change someone’s attitude, you could try to
create dissonance concerning that person’s attitude and hope
that desired attitude change would result. However, there are
other implications of Cognitive Dissonance as well. Much of
the research on dissonance has focused on decision-making,
counter-attitudinal advocacy, forced compliance, and selective
exposure to information.