Decision difficulty and illusion of transparency in Japanese university students

People tend to believe that their inner thoughts are readily apparent to others. This study was conducted to examine effects, related to the difficulty of making decisions of personal preference, on the illusion of transparency, that is, the tendency people have to regard their own preference as more apparent to others when they have made their decision easily as opposed to situations in which they felt their decision to be difficult. In three studies in which the customary "transparency" experimental paradigm was used, university students were asked to rank choices of wedding dresses (Studies 1 and 3) or Korean movie stars (Study 2). Analysis suggested that the less difficulty participants felt in making their judgments (the first and last preference vs mid-ranking preference), the more they expected judgments to be transparent, especially when they had the clear intent to convey their thoughts to others. However, observers discerned first preferences no better than mid-ranking preferences. How inner subjective information contributes to the illusion of transparency is also discussed.