A few years back The Guardian had a fascinating piece on how addictive (and also how disruptive to productivity) checking email is. The 'variable interval reinforcement schedule' of our inbox works in the same way that slot-machines do, rewarding actions only sometimes and not in predictable ways. Whilst there may often be little of importance or interest when we check, every so often there is something really good or that really matters. The unpredictable nature of the frequency of this occurence makes it not only compelling that we check repeatedly, but is one of the best ways to create the strongest of habits.
This FastCompany article (quoting Dr Tom Stafford, whose work was also mentioned in The Guardian piece) mentions about this same effect in the context of social media and browsing as well as email but also talks about how one of the reasons we follow so many rabbit holes and get lost on the internet is because in that environment we find it difficult to separate one task from another – we start with one objective and get led into fulfilling others. Since making decisions (and deciding not to do something is as much of a decision as deciding to do something) requires energy, which is a finite resource, we start suffering from decision fatigue. Says Dr Stafford:
"Technology is all about eroding structure but actually, psychologically, we need more structure, and those things are in tension."