What do people say when they're arguing with someone who just can't seem to compromise?
Be reasonable. Be rational.
But it turns out too much rationality can actually make us more likely to argue with one another, not less.
Research suggests that humans are actually at their most reasonable when they're arguing, picking positions that are easier to defend from criticism and thinking over each choice and word more carefully. But that same reasonableness makes it hard for people to actually compromise or see one another's points. They use all their mental resources trying to overcome another person's argument, and none on examining it or seeing its value.
Our minds seem to deploy reason as a weapon, and a way of defeating another person, and it can blind us to the the truth.
Source: Behavioral and Brain Sciences