Why use social media?

In discussion this morning with some of my staff I asked why they use social media.

What I learned from them was surprising - mostly they claimed they use their phones in bursts, when not required to do something else, so our culture at camp of being busy and around people makes them not miss their social media, whereas in bored/down moments they will reflexively reach for their phones to prevent even a moment of boredom.

The most surprising set of answers was that it seemed like none of them spend much time looking through or keeping up with all of the selfies/snapchats/whatever that all of their online friends are posting, they mostly just enjoy the simple action of capturing themselves (and friends) doing something and then sending it off.

I don't really understand the brain science that's going on here, since if they all know that mostly none of them are looking carefully at each others' posts, the narcissism that often gets attributed to millennials is inaccurate. (it seems like the people who actually are into this science would agree with me)

So if millennials aren't using social media because they are more selfish, they're using it because they're bored, that begs the question - how do we keep them engaged (with or without their cell phones)?