Crying. Screaming. Shouts of “Mami!” and “Papá!” This is what President Donald Trump’s policies sound like on the ground as asylum-seeking families are split apart. In the audio published by ProPublica, though, Border Patrol agents do not appear to show empathy, with one agent hearing the sobbing children and joking that “we have an orchestra here” and that “what’s missing is a conductor.”

In just five weeks, US officials separated more than 2,300 children from their parents at the US-Mexico border. While the Trump administration has been deliberately obtuse about its intents, the “zero tolerance” approach appears to be part of a strategy to scare people from illegally crossing the border — by, essentially, using the possibility of parents losing their kids as a threat.

It’s easy to wonder how any of this is possible. How can someone care so little about children and families that they’re willing to use kids — and separation from their parents — as pawns in immigration policy? And how can the people implementing that policy on the ground hear sobbing children and joke about what’s going on?

One inescapable answer is race. These are, after all, immigrants of color coming from Latin America. Many of the people implementing these immigration policies, from Trump and his Cabinet down to border agents, are predominantly white. And based on the research, that makes them much less likely to view brown kids and their parents with a sense of humanity.

The dehumanization of minority groups

Consider a small 2007 study that examined the aftermath of Hurricane Katrina in 2005. In that study, researchers found that people tended to believe that victims in racial groups that they don’t belong to suffered fewer “uniquely human” emotions like anguish, mourning, and remorse than victims in racial groups that they did belong to. They also found that the aftermath of a natural disaster, perception of fewer “uniquely human” emotions led participants to be less willing to help victims of a different race.

A 2009 study similarly found that when participants looked at images of people in pain, the parts of their brains that respond to pain tended to show more activity if the person in the image was of the same race as the participant. Those researchers concluded that their findings “support the view that shared common membership enhances a perceiver’s empathic concerns for others.” Other studies reached similar conclusions.

There’s a basic concept behind this: Once someone can relate to the person who’s suffering, it becomes much easier to empathize. But since the majority of the public and policymakers in America are white, this line of research suggests that Americans are simply less likely to care for suffering Latinx families.

There’s also research, which Brian Resnick covered for Vox in greater detail, looking at dehumanization, which history and psychological studies show is a key contributor to violence and antipathy toward minority groups. This research has found that Americans outright dehumanize people of certain groups, including Mexican immigrants. (Many of the asylum-seeking families are actually from other Latin American countries, but in the public dialogue, they are often mischaracterized as “Mexican immigrants” — so it’s a useful proxy when looking at this kind of research.)

In one study led by Northwestern University psychologist Nour Kteily, participants — who were mostly white Americans — are asked to rate “how evolved you consider the average member of each group to be,” based on (inaccurate) images of human ancestors slowly changing to walk upright on two legs.

The results: Mexican immigrants, along with Arabs and Muslims, are much more likely to be dehumanized. On a scale of 1 to 100, Americans were rated 91.5 and Europeans were 91.9, while Mexican immigrants were rated 83.7.

This dehumanization appears to be more common among Trump supporters, another study led by Kteily found. That’s “consistent with the idea that support for some of the Republican candidates (and Trump in particular) comes not despite their dehumanizing rhetoric but in part because of it,” Kteily and his co-author, Emile Bruneau, wrote. (This is part of a growing body of research tying racism to support for Trump.)

There are, of course, other possible explanations for Trump’s policies. Some people really do believe in doing everything possible — even carrying out horrific acts — to stop illegal immigration, regardless of the race of the immigrant. And, in general, the American system affords fewer rights to foreigners than it does to US citizens, enabling the poor treatment of foreign families.

But it’s impossible to escape that the victims here are people of color. So when I heard those little children crying for their parents as a Border Patrol agent mocked them, the research on race and dehumanization provided some clarity for what was going on.