Racism

The specter of racism is very real...and very insidious. Apart from dedicated self-admitted racists, most would deny being racist. In fact, they are quite likely to believe that they aren't either. Of course, taking into account the human propensity towards self-deception, this belief must be taken with a pinch of salt.

For example, a person may feel that a certain ethnic group is "inborn" with certain traits. Common accusations include laziness, propensity to violence, use of black magics, etc etc. At an intellectual level, having such inexplicable beliefs is completely unacceptable. After all, most people would not want to be thought of or think themselves racist.

Therein lies the problem: Humans have an incredible ability to see patterns where there is none. Hence we can have people seeing a certain ethnic group acting lazy one out of a hundred times and take it as canon, while rejecting the ninety nine other times the people from that ethnic group worked decently. Worse yet, the human mind appears intuitively incapable of comprehending probability (explaining the popularity of gambling, for example). By a combination of these factors, the human will have convinced herself that a certain ethnic group is possessed of a general poor character. And then we throw in the other irrational, probability-handicapped humans who think the same way...