EarthAround the time last month that Facebook’s audience had grown to an astounding 2 billion people, CEO Mark Zuckerberg announced a change.

“For the past 10 years,” he said, “our mission has been to make the world more open and connected… The idea for our new mission is: bring the world closer together.”

This lofty goal will certainly rouse the cynics. They’ll chalk it up to spin, greed, or hubris.

I don’t see it that way. In reading Zuckerberg’s speech, I’m impressed by what appears to be his genuine desire to bring together our fragmented society.

In his speech, Zuckerberg unveiled two initiatives to enhance Facebook groups. They seem like small steps, though, in light of something else he said: “We need to stay connected with people we already know and care about, but we also need to meet new people with new perspectives.”

This might be the most important part of bringing us together, but maybe also the most challenging. It’s the rare person who routinely seeks out others with different perspectives. What’s far more typical are the clans, cliques, and clubs that we naturally form, largely defined by who is not a member. Being part of the in-group often requires shunning an out-group.

You might be familiar with the psychologist Philip Zimbardo’s Stanford prison simulation experiment, in which he randomly assigned college students to play either prisoners or guards. Within a day, the two groups were at odds, each bitterly denouncing the other.

That kind of intense group identification is the human default mode. Whether it’s a relatively trivial matter (sports) or something more important (politics and religion), we’re quick to choose sides and demonize those who make other choices.

So Zuckerberg’s admirable ambition to bring us closer together bumps up against the unflattering reality of human nature. In effect, Facebook’s software must somehow circumvent our hardwiring, which has been tuned by untold millennia of evolution.

In designing around the peculiarities of human behavior, it’s useful to search for successful exceptions, or what’s been called positive deviance. In this case, are there situations in which people interact with others who have different perspectives, resulting in greater understanding?

I want to focus on one example, because I have personal experience with it—and because I think it suggests an interesting direction for Facebook.

During high school, I was an exchange student in South America, living with a family in Uruguay.

Looking back decades later, I’m struck by how ordinary my time in Uruguay was. I attended school with the boy in the family who was my age, and I hung out with him and his friends. I helped out in the tiny convenience store that was located in the garage of the family’s house. I visited with their large extended family of aunts and uncles and cousins.

There were no epiphanies, no transformational moments. But my perspective changed. What had initially seemed exotic to me when I arrived in Uruguay eventually became familiar. And here was the surprise: when I returned home to the United States, what had been familiar to me for all of my life suddenly seemed somewhat exotic. The smallest details of life became remarkable, because I had seen that they could be different.

I wish that more people could have the experience of being an exchange student. Realistically, though, it’s not scalable to large numbers. But I wonder whether there’s a virtual exchange experience that Facebook could offer to its vast audience of 2 billion people.

I should immediately say that there’s currently no substitute for living in another country. Maybe that’s a project for Oculus, the virtual reality company that Facebook acquired. But I think we can reverse engineer the exchange-student experience, and replicate a small, but crucial part of it in software.

What might that look like? Practically, how would a Facebook Exchange Program work?

I think it could be simple. To sign up, you’d accept an invitation in your news feed. And then you’d basically just have one more Facebook friend. There would be nothing new to learn. You would already know what to do.

You’d probably be paired with someone around your age, but who otherwise had a very different background. Within the United States, it’s easy to imagine pairings that bridged political, geographic, and demographic differences. And with the decent machine translation that we now have, we could also have international pairings of people who speak different languages.

In at least one important way, your daily experience in the Facebook Exchange Program would be similar to mine as an exchange student: it would all seem pretty ordinary.

In your Facebook news feed, you’d now see occasional photos and updates from the new friend you’d been paired with—in the same way that you see things every day from your other Facebook friends. Sometimes you’d like and comment on their postings. Other times, you might want to send them a message.

The Facebook Exchange Program would be decidedly low-key. There would be no consciousness-raising workshops or “Kumbaya” sing-alongs. It would be more like having someone new move in next door, and getting to know them in a neighborly way.

Psychologists call this the mere-exposure effect: the way our feelings about unfamiliar things become more positive over time, simply by encountering those things more often.

Initially, we tend to be uneasy when confronted with something new. And that makes evolutionary sense: it seems plausible that our more cautious ancestors were more likely to survive. With repeated exposure, though, we get increasingly comfortable with what was initially off-putting.

As an exchange student, you usually move to another country, speak a foreign language, and eat different food—among many other changes. But when you strip away those details, the essence of the experience is the mere exposure to the unfamiliar, on a daily basis.

I think a Facebook Exchange Program could provide that mere exposure at scale, bringing millions of people closer together.

This is one way Facebook could bring us closer together