Can you be fooled into defending a choice you never made?

Yes, and the experiments are almost uncomfortably simple. In studies led by Petter Johansson, subjects saw two photographs of people and were asked which they found more attractive. They were then given a closer look at their chosen photograph and asked to explain their choice out loud. But in some trials the experimenter had slipped them the other photograph, using sleight of hand. A majority of subjects failed to notice that the picture in front of them did not match the one they had chosen just seconds before.

Worse, many then confabulated explanations. A man might say he preferred the picture because he prefers blondes when he had in fact pointed to the dark-haired woman and had been handed a blonde. Those explanations must have been confabulated, because they explain a choice that was never made. In a study using ten pairs of faces, only 26 percent of subjects noticed the mismatch, and the reasons they gave were comparable in emotionality, specificity and certainty for faces they had or had not actually chosen.

People did not expect this of themselves. In post-test interviews, 84 percent said that hypothetically they would have detected a switch if it had been made in front of them. The researchers named the failure to detect the mismatch choice blindness. Further research found the same failure for consumer product choices and for political attitudes.

The lesson ties to a wider debate. Richard Nisbett and Timothy Wilson concluded in 1977 that reports on mental processes are confabulated, but in 2002 Wilson admitted that those claims had been too far-reaching, and researchers still argue over how reliable looking inward is.