Is racism learned behavior or human nature?

there is no human nature. it is a holistic term created and over-emphasised by the rationalist school of though which in fact has many irrational thoughts in its basement People naturally feel more at ease with people who speak, act, look like, and behave like the groups with which they are familiar. Historically, people have divided everyone into two groups. They correspond to people I feel safe with and people I don't feel safe with. In the Old Testament, The Jews divided everyone into two groups, Jews and Gentiles. The Greeks divided everyone into two groups, Greeks and Barbarians. The Jews noticed that the Ethiopians were black but still put them into the category of Gentiles. Classifying people into groups of safe and unsafe is human nature. The technique of keeping poor people separated by caste so they will not co-operate to overthrow the wealthy began in ancient India. Making those castes based or race was a later invention. In America attempts were made to keep various castes in ghettoes. That would keep them from competing for the better jobs. That would also keep the poor white Anglo Saxons from cooperating with them to challenge the power structure. The Poles had their ghetto, ditto the Italians, ditto the Chinese, ditto the Serbs, and Ditto the Blacks. Once the caucasians learned the English language, they easily moved out of their ghettoes. Then the Chinese did the same. Black people did not start moving out of their ghettoes until the civil rights act. Right now Democrats and Republicans use Affirmative Action to keep poor whites and blacks separate and rich people in power. Republicans keep trying to chip away at it to please poor whites and Democrats keep trying to protect it to please poor blacks. If it went away, poor whites and blacks might get together and challenge the special privileges of the wealthy.