> Unless social media companies start penalising polarising content and rewarding more constructive posts,

Twitter and Facebook are not shy about having a hand in the conversation. If anything they reward polarizing content, and they've shown interest in censoring wrongthink, but do they have any interest in turning down the temperature?

> these platforms will continue to be swamped by political animosity that risks spilling into real-world turmoil.

It's more than a risk, it's been spilling into real-world turmoil for years.