A Facebook executive has hit back at a whistleblower's claims - supported by the company's own internal research - that the social network's products harm children and fuel polarisation.
Monika Bickert, Facebook's head of global policy management, told The Associated Press on Wednesday "we do not and we have not prioritised engagement over safety".
Bickert said the reason Facebook researches teen wellbeing on Instagram is so the company can build better products and features to support them.
Whistleblower Frances Haugen had testified before the Senate on Tuesday that Facebook knows vulnerable people are harmed by its systems and has not made meaningful changes to prevent that harm.
The platform is designed to exploit negative emotions to keep people on the platform, she claimed.
"They are aware of the side effects of the choices they have made around amplification," Haugen said.
"They know that algorithmic-based rankings, or engagement-based rankings, keeps you on their sites longer.
"You have longer sessions, you show up more often, and that makes them more money."
Bickert pointed to features and tools Facebook has introduced over the years, such as hiding 'like counts' on Instagram, saying that means "when you post something, if you're a young person, you don't have to worry about how many people are going to like your post and whether people will see that".
Facebook's own researchers found hiding like counts did not help make teenagers feel better, according to a report in the Wall Street Journal.