GEOFF BENNETT: Over the past few years, this country has seen a dramatic rise in partisan animosity, with dangerous implications for the health of our democracy.

Judy Woodruff profiles some of the work being done to understand what's driving that trend and what might be done to reverse it.

It's part of her ongoing series America at a Crossroads.

MAN: I would describe my political views as part of the new right.

WOMAN: I would say that I'm left.

JUDY WOODRUFF: If researchers are right, this Heineken beer commercial, which first premiered in 2017, holds important lessons for our democracy today.

WOMAN: It's absolutely critical that trans people have their own voice.

MAN: That's not right.

You can't -- you're a man, be a man, or you're a female, be a female.

JUDY WOODRUFF: In it, people on different sides of the political divide in the United Kingdom are interviewed about hot-button issues, then paired up and asked to build a bar, a task designed to create a sense of teamwork.

Through a series of prompts, they get to know each other.

WOMAN: We know each other better than people who've known each other for 10 minutes should.

MAN: You seem quite ambitious and positive, and you have got this really -- got a glow.

I'm trying to say, your aura is pretty cool.

JUDY WOODRUFF: And then are shown clips from the interviews they gave earlier.

MAN: So, transgender, it is very odd.

We're not set up to understand or see things like that.

WOMAN: I am a daughter, a wife.

I am transgender.

JUDY WOODRUFF: An awkward moment, and then a question posed: Do they want to continue to talk over a beer or walk away because of their differences?

MAN: I'm only joking.

(LAUGHTER) ROBB WILLER, Stanford University: What's interesting, from our perspective, is that showing people this video was -- it was actually the number one intervention we found for reducing partisan animosity.

JUDY WOODRUFF: Robb Willer is a sociologist at Stanford University who directs the Polarization and Social Change Lab dedicated to studying what's driving division in this country and how we might overcome it.

ROBB WILLER: I mean, the way we think about it, polarization has essentially paralyzed certainly the federal government, but also a lot of state and local governments.

And so if you're working on a problem where you want to leverage the power of government to take action, most of the time, you're going to need to have some kind of plan to deal with polarization.

LUIZA SANTOS, Ph.D.

Candidate, Stanford University: Can people bringing people together to talk about their disagreements help?

JUDY WOODRUFF: On the day we visited, Ph.D. candidate Luiza Santos presented some early findings into her research on how participants on different sides of the political spectrum engaged in conversations online over divisive issues, like immigration, gun control and climate change.

LUIZA SANTOS: Conversations can actually reduce people's animosity, improve trust, and reduce moral disengagement.

JUDY WOODRUFF: To her surprise, she found participants were far better at disagreeing than she'd expected.

LUIZA SANTOS: Similar to other people, I had negative expectations about how these dialogues will go, and I think partially because what we see on social media and we see when we turn on our TV is just this really negative heated interactions with people who disagree.

So one of the reasons why is because people have such negative expectations that, when they find a reasonable person that disagrees with them on these issues, they're a bit shocked.

JUDY WOODRUFF: That's reflected in Willer's own research too, that the way Americans have sorted into political tribes with little contact across difference has led to strong stereotyping of the other side.

ROBB WILLER: Technology has definitely contributed to it.

People are more likely to be consuming information in a homogeneous-information environment.

There's also a phenomenon called the big sword, where Democrats or Republicans are increasingly likely to live in different parts of the country, to work in different occupations.

And so you're less likely to encounter somebody who is a friend of yours from high school or a friend of yours from your workplace or is an acquaintance in your neighborhood, who you have a positive feeling towards, but has a different party affiliation from you.

JUDY WOODRUFF: Last year, Willer's team partnered with researchers from four other universities to take different approaches for increasing support for democracy over party, things like honoring election results, regardless of the outcome, ratcheting down partisan animosity, and decreasing support for political violence.

They crowdsourced hundreds of ideas from academics, activists and nonprofits, then tested 25 of them on a representative sample of Americans online.

MAN: I have been brought up in a way where everything's black and white.

But life isn't black and white.

WOMAN: Yes, well, I'm just me.

JUDY WOODRUFF: The Heineken beer commercial was among the most successful.

ROBB WILLER: I think it's a good example of something that's called vicarious contact.

So, one thing that can be helpful is for people to have a warm, direct interaction, cross a group divide and find their stereotypes disabused, develop a personal connection.

Sometimes, we can't do that.

We definitely can't do that easily at scale.

But what if you watched the same thing happened?

You know, what if you watch two people from either side of the divide have an interaction?

You then kind of vicariously have that interaction yourself.

GOV.

SPENCER COX (R-UT): We are currently in the final days of campaigning against each other.

CHRIS PETERSON (D), Former Utah Gubernatorial Candidate: But our common values transcend our political differences.

JUDY WOODRUFF: Other intervention that showed promise, politicians announcing their support for voting and elections, regardless of the outcome, something Utah Republican Governor Spencer Cox did with his rival, Democrat Chris Peterson, during their 2020 race.

CHRIS PETERSON: Now, whether you vote by mail or in person, we will fully support the results of the upcoming presidential election, regardless of the outcome.

GOV.

SPENCER COX: Although we sit on different sides of the aisle, we are both committed to American civility and a peaceful transition of power.

ROBB WILLER: We found, when you show people that, that it increases people's commitment to democracy, people in the general public.

And, as you watch the video, it's a very powerful video.

It's a cool thing that they did.

Could we get high-level Democrat and Republican donors who care about Democratic stability to say, I'm giving money to this race, but if it is contingent on you participating in something like this?

JUDY WOODRUFF: Taking a different tack, yet another intervention highlighted how bad things can get when countries betray democratic norms, showing news clips of civil and economic unrest in countries like Zimbabwe, Venezuela, Russia, and Turkey.

ROBB WILLER: And when people saw this video, their reaction was, oh, I need to actually prioritize democratic norms more.

Democratic backsliding is not something to be trifled with, and they showed less support for democratic backsliding from their own party.

JUDY WOODRUFF: But Willer says the number one strategy for reducing support for political violence, simply accurately describing what members of one party believe to the other.

ROBB WILLER: Democrats estimate Republicans' support for political violence at levels that are 300, 400 percent higher than they really are.

And it's pretty much the same for Republicans perceiving Democrats' support for violence.

When you give people corrective information that fixes those misperceptions, you find that people then will ratchet down their own support for political violence.

It's almost as though people are supporting political violence at the levels they do because they don't want to bring a knife to a gunfight.

They assume they're in a gunfight.

When they find out they're not, they sort of stand down a little bit.

And we even find this - - effects can persist for weeks afterwards, even if you just give people small amounts of statistical information in an online survey.

JUDY WOODRUFF: I mean, you came up with that conclusion last summer of 2022.

Is it having an effect, I mean, in getting the word out that this is what you have learned?

ROBB WILLER: No, not really, I don't think.

(LAUGHTER) ROBB WILLER: Yes, we don't have a clear means to mobilize that information that we have learned about what works and what's true about what people think and put it into action.

Then you have, most of all, I think social media platforms, but also cable news networks have a lot of potential influence, a lot of power, but the problem, not a lot of motivation to take action on this problem.

In fact, they may have the reverse.

They may be benefiting from polarization and from increasing it.

And then you don't have really any obvious actors who have an interest in and the means to effectively intervene on this problem.

JUDY WOODRUFF: So, while we're waiting for cable news to change some of its typical ways of focusing on division in politics, while we're waiting on social media, while we're waiting on the donors to reward working together, rather than going to the extremes, what can people do?

What can individuals do, do you think?

ROBB WILLER: Well, I think one thing is to engage across lines of political difference in a respectful way, try to run towards the fire, rather than away from it, have conversations with your socialist or Tea Party-supporting uncle.

It's always the uncles.

I don't know why.

(LAUGHTER) ROBB WILLER: But whoever that person is in your family or your neighborhood, like, engage with them respectfully, and try to give them that interaction that they're not getting now, where they see that you can disagree with somebody, and it could still be a respectful conversation, JUDY WOODRUFF: Willer and others were heartened by the 2022 midterm results, in which many Republican candidates who promoted election conspiracies lost their races.

DONALD TRUMP, Former President of the United States: 2024 is the final battle.

That's going to be the big one.

JUDY WOODRUFF: And yet, with former President Donald Trump, who continues to deny his own loss in 2020, looking like the strongest contender for the Republican nomination in 2024, Willer says, we are not out of the woods yet.

ROBB WILLER: I think it's very possible it's going to get even worse before it gets better.

We haven't reached that point where powerful interests on the left and right, party leaders, high-level donors have realized, oh, we actually should be working together to work on this Pandora's box that we have opened up.

We haven't gotten there yet.

And that might be the way that it's most realistically going to happen, is that the harms of political division, destabilizing our society, our economy, that unites powerful interests to take some sort of action together.

But, in the near term, all we have is us.

And you can never tell what can happen from the results of collective action.

JUDY WOODRUFF: Amid some very real challenges, signs of hope that Americans can find a way forward.

For the "PBS NewsHour," I'm Judy Woodruff in Palo Alto, California.