Here's an interesting take in the New Yorker on how and why Facebook makes people unhappy.
What causes us to feel bored and, as a result, unhappy? Attention. When our attention is actively engaged, we aren’t bored; when we fail to engage, boredom sets in. As Eastwood’s work, along with recent research on media multitasking, have illustrated, the greater the number of things we have pulling at our attention, the less we are able to meaningfully engage, and the more discontented we become.
[...] Demands on our attention lead us to use Facebook more passively than actively, and passive experiences, no matter the medium, translate to feelings of disconnection and boredom.
In ongoing research, the psychologist Timothy Wilson has learned, as he put it to me, that college students start going “crazy” after just a few minutes in a room without their phones or a computer. “One would think we could spend the time mentally entertaining ourselves,” he said. “But we can’t. We’ve forgotten how.” Whenever we have downtime, the Internet is an enticing, quick solution that immediately fills the gap. We get bored, look at Facebook or Twitter, and become more bored. Getting rid of Facebook wouldn’t change the fact that our attention is, more and more frequently, forgetting the path to proper, fulfilling engagement. And in that sense, Facebook isn’t the problem. It’s the symptom.
In a broader sense, of course, the Internet offers much more opportunity for active engagement than staring at the television. And I'm not sure the point holds more generally. I'm typing this at my usual coffee shop in New York, a city which is a huge blaring multicolored kaleidoscope of things competing for attention - which is what makes it so stimulating. So why does big city buzz inspire, but online multiple pulls of attention enervate?
It must be something to do with energy and depth and unexpectedness. Any amount of shallow celebrity gossip and trivia must depress people after a while.
It must also have something to do with the right amount of stimulus. I'm reminded of Cziksentmihalyi's idea of flow, that the right amount of challenge, at the edge of our capabilities, puts us into a state where time just seems to pass almost without noticing because you are so absorbed in what you are doing.
Still, it's such a common experience now that people pay more attention to their devices than the person right in front of them that it must point to a deeper problem beyond Facebook.
I asked G about it. She says it's like a hunter-gatherer thing. You see something shiny or interesting, and the instinct is to grab it.