Most of us have ways of making other people confirm our favored conclusions without ever engaging them in conversation. Consider this: To be a great driver, lover, or chef, we don’t need to be able to parallel park while blindfolded, make ten thousand maidens swoon with a single pucker, or create a pâte feuilletée so intoxicating that the entire population of France instantly abandons its national cuisine and swears allegiance to our kitchen. Rather, we simply need to park, kiss, and bake better than most other folks do. How do we know how well most other folks do? Why, we look around, of course—but in order to make sure than we see what we want to see, we look around selectively.
For example, volunteers in one study took a test that ostensibly measured their social sensitivity and were then told that they had flubbed the majority of the questions. When these volunteers were then given an opportunity to look over the test results of other people who had performed better or worse than they had, they ignored the test of the people who had done better and instead spent their time looking over the tests of the people who had done worse.
The bottom line is this: The brain and the eye may have a contractual relationship in which the brain has agreed to believe what the eye sees, but in return the eye has agreed to look for what the brain wants.
Daniel Gilbert, Stumbling on Happiness