From Indian socio-cultural background, it is difficult to answer the question instantly and without emphasising the socio-cultural changes that has been brought into in Indian society during the post globalization era unless the legacy of the past is not taken into consideration. Pre-globalized Indian families located in the mixed income housing were looked up as a community and not as a matter of competition. Thus the socio-economic background of the families were never considered a hurdle in maintaining cordial relation among the families. Community was treated as an extended home for all .The children grew up in a surrounding where family demarcation by housing was not a big deal to them. Even most cases they learned to call the neighbouring houses as their extended families. .Globalization has brought about a sudden change in the family relations .Mixing up with the neighbouring families are decided as per family standard. Children are not allowed to mix up with all within the community,Net result is that the children grew up in an artificial environment. They are not allowed to mix up with all . The net result is that they grow up an an individual and suffer from the problem of adaptability and thereby come up to be an odd man in the society.We have seen our children playing with a child from the family of a domestics. They picked up both good and the bad culture but with the change of time they learnt by themselves about acceptable and non acceptable social behaviour and tried to pick up the right attitude by their own pursuit. This is missing now a days. .

Richmond-

I believe your question is a very relevant one, and seems to be one that researchers should gravitate to (if they haven't already).  In the U.S., mixed income housing as a concept for planners is a much ballyhooed and celebrated concept.  Its proponents suggest that by mixing different income groups, households have the chance to build social capital for income groups that in the recent past have been denied these opportunities based on the forced segregation (essentially) of various income levels by neighborhood.  It stands to reason that these same theorists would go further to say that mixing income categories gives these "previously denied" families/households the opportunity to develop more social capital given this new living arrangement.  This then translates to better job opportunities, more friendships, better cultural understanding, etc.

For a few ideas of book/article resources that might help you in your quest (however initial or advanced that quest is), here are a few possibilities:

Massey/Denton --> American Apartheid

Robert Putnam --> Bowling Alone (and several others)

James DeFillipis --> The Myth of Social Capital (a good and sharp critique of Putnam)

Eppli/Tu --> Valuing New Urbanism

Hope that this helps!

Andy Carswell

P.S. I have included a humorous picture that typifies normal American type of development.