
Knowing someone for years provides enormous amounts of information about them.
But familiarity can also create assumptions.
Relationship research suggests partners sometimes rely on established beliefs about each other instead of continuously updating those beliefs.
That's important because people change.
Your partner's preferences, fears, ambitions, and opinions at 30 aren't guaranteed to be identical to what they were at 22.
Sometimes knowing someone extremely well can create the illusion that there's nothing left to learn.
© Journal of Personality and Social Psychology