What could be the reason for the prejudice/bias?

The way your brain learns. You gain significant advantage in learning and thinking by categorizing data in a usable way. Chunking data that is commonly together or has certain meaning when combined permits your brain to work faster. read more

Prejudice and bias are and must be meticulously and carefully taught and ingrained. Such lessons begin in the family first from parents but are often further verified by religious or cult beliefs. Merging with others can paint new or stronger bias amazingly strengthened by fear of ideas not understood or different from the first learned platforms. read more

Prejudice is a baseless and usually negative attitude toward members of a group. Common features of prejudice include negative feelings, stereotyped beliefs, and a tendency to discriminate against members of the group. read more