
Long relationships provide enormous amounts of information about a partner.
But familiarity can also create confidence.
People may believe they already know how their partner will respond, what they want, or what they're thinking.
That assumption can discourage asking new questions.
Meanwhile, people continue changing throughout adulthood.
Sometimes the sentence “I know exactly what you're going to say” prevents you from discovering that you actually don't anymore.
© Journal of Personality and Social Psychology