In a striking attempt to intervene in the health care of a foreigner, lawmakers in Congress are taking steps to grant permanent US residency to a terminally ill British infant to try to help him receive an experimental medical treatment in the US.

Charlie Gard is an 11-month-old in the UK with a rare and fatal mitochondrial DNA disease, and his fate has in the past few weeks morphed into a widely publicized and heated dispute about medical ethics.

The doctors caring for Gard at a hospital in London say it’s time to take him off the ventilator keeping him alive to reduce his suffering in the final days of his life. But his parents are not ready to let go. They want to take him to New York to receive an experimental new treatment that could possibly help him and have been battling the doctors’ decision in court.

Related A psychologist explains the hard limits of human compassion

The case has provoked reaction from world leaders like President Donald Trump and Pope Francis. And in the frenzy, the Gards have raised 1.3 million pounds in donations to help Charlie.

Republicans in Congress were moved by the case, too. GOP Reps. Trent Franks and Brad Wenstrup co-sponsored legislation that seeks to make Charlie a US resident. In a statement, they said Charlie’s case “serves as a powerful reminder that every human life has dignity, including the lives of the voiceless and most vulnerable. God forgive us all if we forget that.”

And yes, these two Congress members voted for the House GOP health care bill, a piece of legislation projected to result in tens of millions losing health care.

Their gesture on behalf of Gard appears to be genuine concern for his well-being. (It also may be an opportunity to make the UK’s nationalized health care system look heartless and unappealing.)

And while it’s easy to call out the apparent hypocrisy, there’s something else this moment elucidates too. There’s a reason politicians and so many others have fixated on the plight of Gard and his parents in the face of a terminal illness. We’re easily moved by the suffering of an individual — but often numb to the plight of the masses.

Why one human life is so often valued more than 10,000

Studies keep finding that we can easily have compassion for individuals, but when we’re confronted with a large number of people in pain, we grow apathetic. Psychologists call it “psychic numbing,” and everyone is susceptible to it.

“We do care a lot about individuals. We don't scale that up, even when we're capable.”

Recently I had a conversation with Paul Slovic, a psychologist who is the world’s leading expert on the topic. He explained to me all the infuriatingly irrational ways psychic numbing rears its head.

As the number of victims in a tragedy increases, our empathy, our willingness to help, reliably decreases. Experiments show this: People are less willing to donate to one little girl in need when they see statistics about the larger tragedy she is caught up in.

There’s a drop-off in compassion when the number of victims in a situation increases from one to two.

“In one of our experiments,” Slovic explains, “we showed that people were less likely to do something that would save 4,500 lives in a refugee camp if that camp had 250,000 people than if it had 11,000 people. It didn't feel as good to save those lives, 4,500 out of 250,000.”

There’s a limit to human compassion. Our compassion is maximized when the number of people in trouble is one. Our feelings don’t always multiply when more people are in trouble.

I don’t want to be dismissive of individual acts of charity and kindness. Again, Congress is well-intentioned here (though Gard’s doctors and other medical experts who’ve validated their decision not to move him have a point too). People who donate to individuals in need of money for operations but not to thousands of kids who could use bed nets for mosquitos are well-intentioned. And, as Slovic says, “Even partial solutions save whole lives.” But we’re all too often blind to the suffering of masses.

“We see it over and over again,” Slovic says. “There's a child who needs an operation, his parents can't afford to pay for this operation, and there's a story in the newspaper, and an outpouring of money donations and support is often tremendous. We do care a lot about individuals. We don't scale that up, even when we're capable.”

Charlie Gard has caught the attention of people all over the world. It’s an arresting case. But it’s worth considering: What else should we be paying attention to?

You can check out the full interview with Slovic here.