Racism
Racism is a pervasive behavior pattern that causes a person or society to discriminate against persons of other races or ethnic/social groups that the racist person or group considers inferior. This type of behavior can range from explicit racism (such as written, verbal and graphic disparagement) to implicit racism (inequities in education, housing, and opportunities).
Racism can also include physical violence against members of the targeted group.
This pattern of behavior has existed throughout history and has caused many unfortunate events ranging from social inequality to slavery, racial warfare and genocide.