Perception: how a person interpret their impression to give meanings to an event.
Selective perception: People only see what they want to see. What they want to see is also based on their own interests, background, and experience.
We all do that, we all judge other people and events based on many other factors, while it should only be about the person him/herself. Just like you heard your co-worker talks bad about another co-worker, and if you don’t try to get to know the other guy, you will spend the rest of your time at the company thinking about how bad that person is.
There is also halo effect. This is simply our first impression on a certain event. For example: you have a very bad impression on a guy and you “decide” right away not to like him. You will spend the rest of your time around that guy trying to find more evidence to prove that you were right in the first place, by looking for more negative things about him. And that, is when you don’t try to get to know him better.
Quote from my lecture notes:
“People’s behavior is based on their perception of what reality is, not on reality itself.”
“The world as it is perceived is the world that is behaviorally important.”
My Very Own Experience at SDSU 