Rich people -- U.S. households making more than $200,000 a year -- who live in enclaves of wealth tend to donate fewer dollars to charities, researchers say. The Chronicle of Philanthropy found when wealthy people were heavily clustered in a neighborhood, the affluent households gave an average of only 2.8 percent of discretionary income to charity -- lower than the overall giving rate in all but four of the nation\'s 366 metropolitan areas. Paul Piff, a postdoctoral scholar in psychology at the University of California at Berkeley, said his research showed as wealth increases, people become more insulated, less likely to engage with others and less sensitive to the suffering of others. However, these class differences evaporated in an experiment he conducted in which both wealthy and lower-income participants were required to watch a short video about childhood poverty. \"Simply seeing someone in need at the grocery store -- or looking down the street at a neighbor\'s modest house -- can serve as basic psychological reminders of the needs of other people,\" Piff told the Chronicle. \"Absent that, wealth will have these egregious effects insulating you more and more.\" The Chronicle\'s study of tax records showed of the top 1,000 ZIP codes that give the biggest share of income, only nine are among the nation\'s 1,000 richest ZIP codes. In city after city, giving levels are higher among the low-income residents, the study said.