Some new research may help us understand the divide over President Trump’s zero tolerance immigration policy. While the majority of Americans found the practice of separating families at the border objectionable, about a quarter of Americans supported the practice.

Emile Bruneau, director of the Peace and Conflict Neuroscience Lab at the University of Pennsylvania’s Annenberg School for Communication, sees echoes of other colonial policies that stemmed from a belief that the people involved were less than fully human. It’s an attitude that has often been equated with an extreme version of dislike. But Bruneau’s research debunks that idea and points to possible ways of changing such views.

“There was a general assumption that blatant dehumanization might have just been a thing of the past,” Bruneau recalls, “that it was there for colonialism and slavery, but that we didn't really hold these views widely. We wanted to test that.”

To do that, Bruneau and colleagues have given people a copy of the Ascent of Man diagram and asked them rate where on that evolutionary progression they thought various groups of people fell. They found that people were perfectly willing to declare others, particularly marginalized groups, less evolved and civilized — less human — than themselves. That held true across at least a dozen countries on three continents.

“When the data come in looking at the degrees of dehumanization across group boundaries, the data are beautiful and they're completely depressing,” said Bruneau. “That part of it is really miserable.”

But Bruneau also sees a silver lining. His research has shown that dehumanizing attitudes are often based on stereotypes or perceptions that can be proven factually false, and that correcting those misconceptions can reduce dehumanizing tendencies.

In the case of family separations, Bruneau points to widespread overestimates of the number of migrants who are members of violent gangs, like MS-13. The Department of Homeland Security says it’s about 1 percent, but Democrats and Republicans tend to think it’s 10 or 24 percent, respectively.

“Both groups are dramatically overestimating, and that estimate feeds into their dehumanization of these groups,” Bruneau says. “That, in turn, feeds into their resistance to allowing these migrants to come into our country and their support for policies like removing their children from them.”

Bruneau says that points to a concrete opportunity for reducing dehumanizing attitudes that feed conflict.

“The fact that we can implement some really simple interventions and see measurable change, that's really exciting,” said Bruneau.