How Social Media Can Shape Public Opinion – and How We Can Build a Healthier Online Environment

Social media has transformed how people encounter information and how they participate in public conversation.

Platforms make it possible for individuals - not only institutions - to reach large audiences, and for audiences themselves to determine what gains visibility by choosing what to share, like or remix.

That dynamic has elevated the role of influencers: figures who combine personal connection with the capacity to drive narratives, said Renee DiResta, associate research professor at the McCourt School of Public Policy. Their success often depends on producing content that resonates strongly within their niche community, which can sometimes mean amplifying divisive material, she said.

"The result is an environment where viral attention often outweighs accuracy, and where rumors can harden into reality through repetition and validation," she said. "This ecosystem can drive polarization and make it harder for people to agree on basic facts."

DiResta studiesadversarial abuse on online social media platforms and is the author of Invisible Rulers: The People Who Turn Lies Into Reality, which explores how algorithms, influencers and crowds interact to shape public opinion.

"Because they seem just like us, influencers don't feel like media in the traditional sense," DiResta said. "I got interested in the rise of the influencer as a figure unique to this particular information ecosystem, and in their role in shaping public opinion."

In DiResta's current research, she studies how political manipulation campaigns work, ways that institutions need to adapt to participate in the current information environment, and tools such as middleware, a type of software, that gives users more power to determine the content they see online.

We sat down with DiResta to explore how we got to the current social media landscape, the role influencers play in politics and the potential solutions that could contribute to a healthier online environment.

How has social media enabled the rise of influencers in politics?

In prior other communication eras, the audience was primarily listening - receiving a message. Audiences today are not only recipients of messages - they're participants, which gives them a lot of power.

When something goes viral, it goes viral because a whole lot of people take action, hitting the like button, the retweet button, the share button. A whole lot of people decide that a piece of content or theme is so emotionally resonant, they are motivated to propel it onward. The audience collectively influences what gets seen by sending a signal to an algorithm, as opposed to in other media ecosystems where an editor, curator or publisher has the power to make that determination.

How do influencers, algorithms and audiences work together to shape public opinion?

Influencers produce content tailored to the values of their audience and also formatted for what algorithms are likely to reward. Algorithms detect early signs of engagement and boost what performs. Audiences react - through comments, likes, shares - and in doing so, signal what should be amplified further and what the creator should make more of. This feedback loop is what determines what spreads and what fades.

This happens across the political spectrum and across advocacy topics. It's powerful because it's participatory. There's no 'media' versus 'audience' distinction here. The followers are co-creating, remixing, creating memes, setting norms for their communities that extend beyond the online world. A single post can become a narrative through repetition and crowd validation. Rumors can go wildly viral and harden into beliefs - think about the story of 'eating the pets' during the 2024 Presidential campaign.

How do influencers differ from traditional media personalities when discussing politics?

Mainstream outlets still carry expectations of balance or neutrality, whereas people expect influencers to have a strong point of view. That's because most influencers gather their audience by appealing to an initial community that sees them as a fellow member, whereas mass media outlets grew by appealing to a broad spectrum of the American public.

What financial incentives do these influencers have to create more polarizing content?

Direct patronage models that many influencers rely on - like subscriptions or donations - tie income to maintaining audience loyalty. That can create pressures to lean into stronger positions in line with their audience's pre-existing opinions, or being extremely sensational, since there's competition for limited attention and money.

There are comparatively low barriers to entry - anyone can set up a Substack or Instagram or YouTube channel - so the incentive to stand out often rewards sharper, more provocative takes. This is a big reason why you see the phenomenon known as 'audience capture,' where an influencer will gradually move to take more extreme positions or will trend toward agreement with their audience.

Will traditional media eventually fall away?

I don't think it'll fade away entirely. I still subscribe to paid outlets. I pay for the Wall Street Journaland the New York Timesbecause, for $5-20 a month or whatever the going promotional rate is, I get a very wide collection of topics, from breaking news to commentary. Most of what influencers are producing, to be clear, is commentary.

I think eventually we are going to see some consolidation. We're going to reinvent magazines as Substack creators realize that being independent is actually very, very hard work. It might not be with the backing of something massive like a Hearst umbrella behind it, maybe it'll be more of an indie collective model, but the economics of paying $9-15 a month for dozens of individual Substacks or channel subscriptions does not work out.

What opportunities does the government have to shape the social media landscape?

We have not seen much in the way of tech regulation in the U.S. short of the recent passage of the Take It Down Act. We have little that gives us transparency or accountability. Passing laws that give Americans visibility into what the massive companies in this critical ecosystem do is important.

I've written a lot about the Digital Services Act recently. It's a sweeping piece of legislation in Europe. But because it is so sweeping, it [only] does some things well while other things are a bit too vaguely written by American standards, but they did pass something. On a transparency front, it provides a lot of rights to data access. If your content is moderated or your account is taken down, you have a right to understand why and to petition to have it back. There are things codified under law in Europe that we don't have here.

On the flip side, they have more in the way of requirements that platforms address certain types of speech that aren't necessarily in line with American values. But they are regulating private companies in their market, in line with their values - so it will be interesting to see how those requirements translate into enforcement.

Are there any digital solutions citizens can use to avoid inflammatory content?

Yes, there are emerging tools that give users more agency over what they see. That's why I'm interested in things like middleware that enable users to have more access to tools to help inform themselves. Things like Community Notes. Education and digital literacy.

Middleware is software that actson behalf of a user. On X, there was a tool called Block Party. Block Party made it possible to have far more control over your X experience. If you were an X account with a large following, you would occasionally get deluged with harassment. With Block Party, you could click a button, and it would block all the people who had liked a particular tweet. This is not a use case for everybody, but for high-profile accounts or people subject to abuse because of their line of work, it's incredibly useful.

So you can envision tools that are third-party providers that curate and moderate content for you, creating custom feeds for you that make your social media experience more tailored to you and more pleasant.

Can't middleware also contribute to echo chambers and polarization?

Absolutely. One of the things that has to shift is the norms and culture. That is an interesting challenge that is not just technical. You can only go so far with the tech.

Some of the interesting work that we are doing here at Georgetown is exploring what's called bridging. Can you curate a feed that, rather than showing the most sensational engagement bait, surfaces content that uses language that gets positive engagement from divergent communities?

But technology alone can't solve polarization; norms and incentives also matter. When the most prominent influencers in your group are telling you that the other group is an enemy, it creates a resistance to engaging. That's where I think influential voices have a responsibility to turn the temperature down. But they just aren't incentivized to, at the moment.

Why is it important for users to have more control over what they see online?

When a feed is shaped entirely by opaque platform decisions, people have little insight into why certain posts are prioritized. That asymmetry of power matters. Giving users more say doesn't eliminate all problems, but it introduces transparency and agency into the process.

What role does the individual have in choosing the content they consume? Do they have any control?

Of course. Platforms may structure the environment, but we decide in the moment whether we're going to hit that share or like button. We're not powerless. Recognizing that agency is part of building healthier online habits.

• McCourt School of Public Policy