Prejudice may come form the heart or mind. Sometimes, people may be prejudice towards someone or something just because he/she don't like the person or thing. Apart from the heart, I think sometimes prejudice may be formed due to people's understanding/misunderstanding towards something. Due to the lack of understand, the wrong impression can be formed and prejudice could result. On the other hand, prejudice could also stem from the understanding of something, which lead to a negative feeling towards the subject, and thus forming prejudice.