Distinction bias, a concept of decision theory, is the tendency to view two options as more distinctive when evaluating them simultaneously than when evaluating them separately.
One writer has presented what he called "a simplistic view" of distinction bias: When asked if someone would like an apple, they may say "Yes". So, an apple is placed before them and they begin to eat it and are happy. But what if two apples were placed on the table - one was the one they would have happily eaten and the other which is slightly fresher looking. The individual will choose the fresher apple and eat it and be happy but if asked, "would you have enjoyed eating that other apple", they would likely say "No". Even though in the alternate, no-choice reality they were perfectly happy with the apple. Moreover, if presented with five apples on a table, they might examine each apple so that they would be sure they had the best one, even though the time spent making that decision would be wasted. The reason for this is that distinction bias causes individuals to "over-examine and over-value the differences between things as we scrutinize them."[1]