A couple is discussing how to spend the holidays. One partner wants to travel to see family. The other wants to stay home. “We always spend the holidays with your family,” one says.

“That’s not true,” the other replies. “We stayed home two years ago.”

Almost immediately, the conversation becomes an argument about facts. Who is remembering correctly? Whose family has received more time? Who has sacrificed the most? Each person is listening for weaknesses in the other’s argument and gathering evi...