First, there is the Abilene Paradox, in which a group makes a decision none of them wants, because each thinks the others are in favor and wants to go along. The additional paradox is that primarily happens among people who like each other. One can see how this type of decision can be reached, sometimes through a martyred attitude, but other times quite innocently.
The following is attributed to the very clever Sydney Morgenbesser: Facing the choice between apple and blueberry pie at his local diner, he opted for the apple. When subsequently informed that there was also some cherry pie available, he switched his choice to the blueberry pie. It sounds impossible, yet we make decisions in this way all the time. Not so starkly and in such compressed time, for then the humor would leap out at us. But in primary elections, hiring decisions, and even on major purchases, humans are prone to this.