Facebook (FB) whistleblower Frances Haugen testified in the Senate Tuesday about a trove of documents she says point to Facebook’s “destructive impact” on society that has led to, among other things, ethnic violence in Myanmar and Ethiopia.

“My fear is that without action, divisive and extremist behaviors we see today are only the beginning,” Haugen told the Senate consumer protection subcommittee. “What we saw in Myanmar and are seeing in Ethiopia are only the opening chapters of a story so terrifying, no one wants to read the end of it.”

Facebook has been blamed for helping to spread misinformation, disinformation, and hate speech that has led to sectarian violence and ethnic cleansing in Myanmar and Ethiopia.

Haugen’s testimony follows her appearance on “60 Minutes” on Sunday during which she discussed the information from her data leaks, and said that Facebook “has realized that if they change the algorithm to be safer, people will spend less time on the site, they'll click on less ads, they'll make less money.”

The Wall Street Journal initially published Haugen’s revelations in a series of articles discussing everything from the impact Facebook’s Instagram has on teens and young women to how Facebook is used by human traffickers in foreign markets.

During her Senate testimony, Haugen, who previously worked in Facebook’s Civic Integrity division, asserted that the company’s engagement-based algorithms incentivizes divisive content, since that ends up being shared more widely than non-divisive content.

According to Haugen, Facebook is aware of this, and knows that it should change its algorithms, but doesn’t because it fears doing so will mean less user engagement and result in less advertising revenue.

“The dangers of engagement-based ranking are that Facebook knows that content that elicits an extreme reaction from you is more likely to get a click, a comment, or a reshare. And it’s interesting because those clicks and comments and reshares aren’t necessarily for your benefit,” Haugen said.

“It’s because they know that more people will produce more content if they get likes and comments and reshares. They prioritize content in your feed so you will give little hits of dopamine to your friends so they will create more content. And they have run experiments on people...that has confirmed this.”

Much of the senators’ questions had to do with Instagram’s impact on teens, and Facebook’s plans for a version of Instagram for children under 13. Facebook’s internal documents provided by Haugen found that 32% of girls in one survey reported that when they felt bad about their bodies, Instagram made them feel worse.

Since The Wall Street Journal’s original reporting, Adam Mosseri, the head of Instagram, announced that the company was putting plans for its so-called Instagram for kids on hold, but not cancelling it.

Facebooks says there are already children under 13 using Instagram, and that a kids-friendly service would provide protections for younger users complete with parental oversight.

But Haugen says that the true reason for Instagram for kids is to ensure Facebook has a steady supply of users, and that children in particular have found it difficult to stop using the service on their own.

“One of the documents we sent in on problematic use examined the rates of problematic use by age, and that peaked with 14-year-olds,” Haugen said. “It’s just like cigarettes. Teenagers don’t have good self-regulation. They say explicitly, ‘I feel bad when I use Instagram, and yet I can’t stop.’ ”

During a hearing last week, Facebook head of global safety told senators that the decision to either move forward with an Instagram for kids or not will come down to a conversation among top executives at the company.

But Haugen explained that’s not likely the case.

“Mark holds a very unique role in the tech industry in that he holds over 55% of all of the voting shares for Facebook. There are no similarly powerful companies that are as unilaterally controlled. In the end the buck stops with Mark," she said. "There is no one currently holding Mark accountable but himself.”
Sign up for Yahoo Finance Tech newsletter

More from Dan

• Facebook outage: Why the world's largest social network was down for 6 hours

• Microsoft Windows 11 review: Big upgrades for workers and gamers alike

• Apple is relying on the iPhone 13's new cameras to power record sales

Follow Yahoo Finance on Twitter, Facebook, Instagram, Flipboard, LinkedIn, YouTube, and reddit

Got a tip? Email Daniel Howley at [email protected] over via encrypted mail at [email protected], and follow him on Twitter at @DanielHowley.