Explicit attitudes are the conscious and chosen attitudes that a person displays while interacting with the world. These are the behaviors and beliefs that others see.
For instance, a person may have grown up in a family or culture where extreme prejudice against other ethnic groups (implicit attitudes) are deeply ingrained. Implicit attitudes are unconscious and uncontrolled. However, with age, distance, and education a person may choose to adopt an inclusive and non-prejudiced "explicit attitude."