by Yunkyu Sohn
What we do when we confront multiple contradicting ideas? The theory of cognitive dissonance asserts that people tend to manipulate their preference, attitude or opinion to evade such uncomfortable situations. Psychologists developed a standard experimental setup to assess the presence of such tendency. In this setup, the experimenter asks subjects to rank N objects according to their preference and offers n<N objects to them. After the transaction was made the subjects are asked to re-rank N products. Many experimental studies have found that the subjects are likely to alter their preference ordering. That is, they tend to rank those n objects higher afterward. Two fMRI studies (Sharot, Martino and Dolan 2009; Veen et al. 2009) revealed that dorsal anterior cingulate cortex anterior insula, caudate nucleus and amygdala underly certain behavior.
In a recent Brevia published in Science, Lee and Schwarz report that ordinary hand washing task removes the consequential preference shift caused by cognitive dissonance. This study extends the findings of previous studies which examined the role of physical cleansing on compensatory behavior and moral judgement, and demonstrates that it also has implications on people’s preference consistency. The link found in these works may elucidate result of voters’ physical and physiological activities on their political attitudes and decisions (see Mullainathan and Washington on cognitive dissonance in voting).