Editing Leon Festinger (section)

===Cognitive dissonance===
{{main|Cognitive dissonance}}
Festinger's seminal 1957 work integrated existing research literature on influence and social communication under his theory of cognitive dissonance.<ref>Festinger, 1957</ref> The theory was motivated by a study of rumors immediately following a severe earthquake in India in 1934. Among people who felt the shock but sustained no damage from the earthquake, rumors were widely circulated and accepted about even worse disasters to come. Although seemingly counter-intuitive that people would choose to believe "fear-provoking" rumors, Festinger reasoned that these rumors were actually "fear-justifying."<ref>Festinger, 1957, p. 236–239</ref> The rumors functioned to reduce the inconsistency of people's feelings of fear despite not directly experiencing the effects of the earthquake by giving people a reason to be fearful.

Festinger described the basic hypotheses of cognitive dissonance as follows:

:1. The existence of dissonance [or inconsistency], being psychologically uncomfortable, will motivate the person to try to reduce the dissonance and achieve consonance [or consistency]. 
:2. When dissonance is present, in addition to trying to reduce it, the person will actively avoid situations and information which would likely increase the dissonance.<ref>Festinger, 1957, p. 3</ref>

Dissonance reduction can be achieved by changing cognition by changing actions,<ref>Festinger, 1957, p. 6</ref> or selectively acquiring new information or opinions. To use Festinger's example of a smoker who has knowledge that smoking is bad for his health, the smoker may reduce dissonance by choosing to quit smoking, by changing his thoughts about the effects of smoking (e.g., smoking is not as bad for your health as others claim), or by acquiring knowledge pointing to the positive effects of smoking (e.g., smoking prevents weight gain).<ref>Festinger, 1957, p. 5–6</ref>

Festinger and James M. Carlsmith published their classic cognitive dissonance experiment in 1959.<ref>Festinger & Carlsmith, 1959</ref> In the experiment, subjects were asked to perform an hour of boring and monotonous tasks (i.e., repeatedly filling and emptying a tray with 12 spools and turning 48 square pegs in a board clockwise). Some subjects, who were led to believe that their participation in the experiment had concluded, were then asked to perform a favor for the experimenter by telling the next participant, who was actually a confederate, that the task was extremely enjoyable. Dissonance was created for the subjects performing the favor, as the task was in fact boring. Half of the paid subjects were given $1 for the favor, while those of the other half received $20. As predicted by Festinger and Carlsmith, those paid $1 reported the task to be more enjoyable than those paid $20. Those paid $1 were forced to reduce dissonance by changing their opinions of the task to produce consonance with their behavior of reporting that the task was enjoyable. The subjects paid $20 experienced less dissonance, as the large payment provided consonance with their behavior; they therefore rated the task as less enjoyable and their ratings were similar to those who were not asked to perform the dissonance-causing favor.