I wrote a post recently based on something that 19-year-old Andrew Watts published on Medium, about the way he uses various social media networks. It was a fascinating look at how different services — from SnapChat and Instagram to Facebook and Twitter — appeal or don’t appeal to Andrew and his friends. But as sociologist and teen expert danah boyd rightly points out in a follow-up post at Medium, it’s dangerous to extrapolate too much from what one teenager like Andrew does with social media.

This is something that boyd (who chooses to spell her name without using capital letters) is in a position to know better than just about anyone, because she has spent more than a decade studying the way that teenagers use social media, and has written a number of fascinating papers as well as a book devoted to what they do and don’t do.

In her…