I was glad that the author did not end up taking religious overtones even though it seemed as if he started from such a position. Not talking of discrimination in general and restricting ourselves to the issue of housing, this exists everywhere where residents want more of their ilk to come in. Perfectly 'human' tendency though not rationally justified. To make it aplotical, even Hindus discriminate against each other (well, this is known - the caste system) even wrt housing. Like, brahmin-dominated societies do not wish non-brahmins to come in. I forget a beautiful quote, which went something like 'If one morning all the prejudices on the basis of caste, creed, colour, race were to disappear from the world, people will find something new by afternoon to discriminate against each other'. To reiterate, it is 'natural' for us to discriminate, perhaps reflecting our subconcious insecurities and survival instincts, but not 'rationally' justified. Let's strive for the ideal world!