‘Likes’ and ‘shares’ teach people to express more outrage online: study
I remember the way that old style internet forums used to work.  It was the posts that generated the most active discussion that naturally "rose to the top" simply because forums were designed to display the posts in order of recent activity.  And there was no signal such as "likes" or "votes".  So you had to read through the entire thread to decide what you thought about an issue or what your takeaway should be.