Choice blindness refers to a short-term memory phenomenon that causes people to be unable to accurately recall choices made. For example, several research projects have asked participants to look at pictures of people and to choose the one that they find most attractive. Once selected, it is frequently possible for the researcher to substitute a different picture for the one selected without the subject being aware of the substitution. Then, when asked to describe why they found their choice most attractive, to create lengthy explanations to explain their choice.