It would be interesting to take a random sample of Facebook/Instagram/Twitter users and remove the ability to see likes for a few months and see what engagement and post frequency looks like.
I have a feeling the companies might already know.
Well you can I guess for a rough estimate compare your own use of say HN to websites with gamified mechanisms. From my own experience with Reddit HN is considerably less addictive and I attribute it to a large degree to the lack of instant notifications, the plain design and the diminished visibility of up- and downvotes.
Up here in Canada we already can't see likes on Instagram posts and I'm not sure I've seen any difference w. r. t content posted (even from mainly local accs that only deal with a Canadian audience)
Can’t see the number of likes or can’t see that it is liked at all? I have a feeling removing the number helps but I know a few people who like to scroll through all the likes they get.
I have a feeling the companies might already know.