Topix Underground

On a very superficial level for US students that may be true. When I was at CU - the department I worked for was number one or number two in the world, competing with UC Berkeley. We had grad students from all over the world. Nothing to do with zip codes or DNA. I met parents from Tibet, Persia (yes that's where he said he was from), China. Russia.

Eh, as a general rule I expect that it is mostly true in that a Zip can indicate social and financial standing.