"It's the most negative prejudice people report," greater even than racism, Fiske said.
That's an everyday truth in Philadelphia, said Zarah Teachey, 58, a formerly homeless woman from West Philadelphia who now counsels others.
"You're looked at like you're trash," she said. "It's like they think you want nothing out of life. Like you're not still a person."
Adam Bruckner's brain would have lit up with his personal prejudices when he was younger, said the youth director at Helping Hand Rescue Mission, a Philadelphia faith-based organization that works with the poor and homeless. To him, homeless "bums" contributed nothing, like women on welfare who he believed had babies to score government cash.
"Then I saw the money you get isn't worth the stretch marks," he said. "Once I met the mom, and the homeless person, it changed me. I saw the humanity inside."
People are savvy enough not to vocalize that the poor sicken them, Fiske said. But as a social psychologist, she can dig deeply enough to learn what loathing looks like in people's minds.
"And," she said, "once you've dehumanized a person, it's easier to neglect him."
That kind of neglect is always on display, even without a brain scanner, said Sister Mary Scullion, cofounder of Philadelphia's Project H.O.M.E., which helps the homeless. She was named one of Time magazine's World's Most Influential People in 2009.
"We're losing part of our humanity," she said. "These were the seeds to the Holocaust: That some lives matter more than others."
Prejudice against the poor increases during hard economic times, said John Dovidio, a Yale University psychology professor.
"Our society is based on the idea that if you work hard, you get more, and if you have less, you deserve less," Dovidio said.
That's why, he added, many Americans don't accept the notion that low-income people are deserving of support because they're disadvantaged by adversities outside their control.
"You got to look [poor] people in the eye and tell them they're irresponsible and lazy," conservative TV host Bill O'Reilly once said. He added, "That's what poverty is. . . . In this country, you can succeed if you get educated and work hard. Period."
Those widely held ideas were buttressed years later by the equally prominent broadcaster Rush Limbaugh, in a now-famous 2010 radio diatribe directed at low-income children in the summer, for whom free school lunches are unavailable:
"There are . . . things in what's called the kitchen of your house called cupboards. . . [where] most likely you're going to find Ding-Dongs, Twinkies,. . . [and] potato chips.. . . If that doesn't work, try. . . McDonald's. . . and if they don't have Chicken McNuggets, dial 911 and ask for [President] Obama." He added, "There's always the neighborhood Dumpster," where he advised hungry children "to . . . dive and survive until school kicks back up in August."
Listeners heard racial overtones in the monologue, and in many Americans' minds, poverty and race are linked, Dovidio said: "People stereotypically associate blacks and Latinos with poverty."
For a lot of people, it's easier to say that all minorities are poor, and that all poor people have only themselves to blame, than to recognize that inequality and unfairness abound, and that not everyone gets a fair shake in a complex world, Dovidio said.
His Yale colleague Elijah Anderson, a sociologist famous for his studies of the Philadelphia streets, understands the race-poverty linkage.
"Black skin is a marker for being lower-class," Anderson said. "Race and poverty are often conflated, associated with the iconic urban ghetto."
Mariana Chilton, director of the Center for Hunger-Free Communities at Drexel University's School of Public Health, agrees.
"Racism and bigotry blanket our country in a suffocating way," she said. "And if there's no sense of a social bond among people, then it's easy to view others as non-human."
In poverty-prejudiced America, few believe that the American Dream - that anyone who tries can make it - is flawed, noted Nicole Stevens, a cultural psychologist at Northwestern University. It's easier to blame the poor.
"People focus on individual responsibility, but fail to see that the dream is not accessible to a large segment of the population," Stevens said.
Not everyone living on society's lower rungs will allow negativity to influence them, though. Joel Murph, 58, a homeless man from North Philadelphia, said he resists labeling.
"I won't allow people to think of me as less than," he said at Project H.O.M.E., where he stopped in to wash his clothes.
"I have enough trouble on my hands to worry about how somebody views me."
Contact Alfred Lubrano at 215-854-4969 or firstname.lastname@example.org.