Project Implicit is a non-profit international collaboration that investigates implicit social cognition or the thoughts and feelings we all have outside of our conscious awareness and control. To find out if you have an implicit attitude take one of the projects Implicit Association Tests (IAT).
An example of an IAT is Age ('Young - Old' IAT). This IAT requires the ability to distinguish old from young faces. This test often indicates that Americans have automatic preference for young over old.