Cognitive blindnesses

From a recent issue of Science:

"Curiously, people seem to be unaware of their own unawareness, rarely answering "I don't know" when asked to explain their decisions. People freely give reasons for their preferences, even when it is clear that these reasons are confabulations and not accurate reports. In one study, for example, researchers showed participants photographs of two women and asked them to choose the one they found more attractive. The experimenter then showed people the photograph they preferred and asked them to explain the reasons for their choice. On some trials, through sleight of hand, the experimenter actually showed people the photograph they found less attractive. It might seem that people would immediately see through this ruse, but surprisingly, they noticed the switch only about a quarter of the time. Even more surprisingly, in the 75% of the trials in which they did not notice the switch, participants had no problem coming up with plausible reasons for their choice. One participant, for example, said, 'She's radiant. I would rather have approached her in a bar than the other one. I like earrings'--even though he initially found the other woman, who wasn't wearing earrings, more attractive. Perhaps most tellingly, the researchers could not find any differences in the kinds of reasons people gave for their real versus their false choices, suggesting that people were confabulating reasons in both cases." (Wilson and Bar-Anan, Science 321(5892):1046-1047.)

Reminds me of the amazing demonstration in this video:

Or the many cool cognitive effects Richard Wiseman details in his excellent book, (which I cannot recommend enough) and in his YouTube videos: