As the rich get richer and the poor fall further behind, levels of happiness and satisfaction drop, but only among people with modest and lower incomes, a new study shows. The finding holds true for about 60 percent of Americans, according to research that will be published in the journal Psychological Science. "Income disparity has grown a lot in the U.S., especially since the 1980s. With that, we've seen a marked drop in life satisfaction and happiness," said Shigehiro Oishi, a psychologist at the University of Virginia.