Prejudice: Benign ignorance vs hostile bigotry?

I am curious, where is the line between simple ignorance about other cultures/races/religions etc and hostility toward them? As human beings, we are all unfortunately prone to wrongly stereotyping others based on various things (religion, culture, race, ethnicity, gender, etc). Sometimes this is manifest in ways that betray simple ignorance rather than hostility along with ignorance, which amounts to bigotry. On the other hand, any stereotype is negative and hurtful toward those it is directed against. Therefore, is bigotry an extreme form of prejudice or is simple prejudice a softer form of bigotry?