How does life in the U.S. vary for those with low, middle and high incomes? Quite a lot, according to a new survey. In fact, how much money people make plays a huge role not only in how they manage everyday and unexpected expenses, but how they regard their lives. According to the survey by the Harvard T.H. Chan School of Public Health, NPR, and the Robert Wood Johnson Foundation, U.S. income inequality is at its highest level in 50 years. And that's taking a toll on a great part of the population, affecting the essentials of life in ways that make it seem as if the opposite ends of the income spectrum actually live in different societies. The study explores the "starkly different life experiences" of those who earn at least $500,000 a year (the top 1 percent), those in the middle-income category ($35,000–$99,999) and those on the lower-income end of the range (less than $35,000) and their experiences with financial stress, health care and life satisfaction.  It also includes responses from people in a higher income category (those earning $100,000–$499,999), but adds that its analysis "focused mostly on differences between the top one percent and those in the lower- and middle-income categories." While just 4 percent of the top earners encounter major financial problems, it found, a whopping 67 percent of lower-income adults and 34 percent of middle-income adults say they'd have a tough time coming up with the funds to meet an unexpected expense of $1,000. "It is simply unacceptable in a country as wealthy as ours that so many people lack sufficient income to pay for health care, housing or even food," Rich Besser, president and CEO of RWJF, is quoted saying. Besser added, "We need to address income inequality if we truly want everyone to have a fair and just opportunity to live the healthiest life possible."