Thirdly, ignorance. If you don’t experience contact with the groups you prejudiced about, probably because of your prejudice, your assumptions will never be challenged. Ill educated people are more likely to be prejudiced because they don’t appreciate the rich multicultural world we live in. Fourthly, by having contempt for one or more other groups of people, some people validate their own status, and/or justify abuse of those groups, or seek to justify preferred treatment for their own group. For example in slavery, or in employment rivalry.n Fifthly, political goals. It is often an easy way to gain political votes and donations, if you blame a minority group for the ills of a situation and scape goat them. This misleads the public into thinking that if they support you you will remove the scape goated group and you can imply that this might make more jobs or benefits available for your supporters. This enables you to gain power and the personal benefits that go with it.
For example the Nazis in Germany, the nationaists in Yugoslavia, and the BNP in the UK, or Mugabe in Zimbabwe. No-one gets their money back, if you don’t get enough power to make any changes, or you do, and the changes make no difference, or you do and the people starve, or you do and you get oppressed by another power. In all cases you still get paid. Many of the people who voted for you will refuse to accept that they were fooled, and perpetuate your claims, even after they have been proved wrong, because to accept that the claims were wrong, is to accept that they are fools, and responsible for the consequences of voting for you. To address the last point of the question, although I think it’s an assumption, kids often like to rebel from their parents, and that might mean getting to know people their parent’s wouldn’t approve of, or it might mean, telling it how they see it, if they think their parents are liberal – although this is normally a product of the influence of others. It’s quite common for siblings to adopt opposite views. My brother and I are currently at opposite ends of the stimulus debate. In the case of something shameful like prejudice, I think the shame of having one of the most similar people in the world to you, holding the opposite view, probably would make someone more forceful in their views.