(1) This article is pretty low-quality, and provides no sources for anything. It certainly sounds plausible enough, but still...
(2) Assuming that this is true for Facebook, I'm pretty sure the same result would hold true for any other social media site for short-form content (e.g. Instagram, Twitter, LinkedIn, etc).
(3) I'm LESS sure about sites for sharing longer-form writing, such as Reddit and HN. I suspect that the effect is not as stark, but that it does hold true to SOME extent whenever you have the gamification of upvotes and downvotes.
(2) Assuming that this is true for Facebook, I'm pretty sure the same result would hold true for any other social media site for short-form content (e.g. Instagram, Twitter, LinkedIn, etc).
(3) I'm LESS sure about sites for sharing longer-form writing, such as Reddit and HN. I suspect that the effect is not as stark, but that it does hold true to SOME extent whenever you have the gamification of upvotes and downvotes.