Bearing in mind all the anguished posts on mn about fb i thought some might find this interesting -
digest.bps.org.uk/2015/01/the-psychology-of-facebook-digested.html?utm_source=BPS_Lyris_email&utm_medium=email&utm_campaign=Newsletter
(disclaimer: I'm not being unreasonable but I probably should have posted in chat - but i only ever see the fb threads in aibu!)