I recently signed up for and attended a writing retreat. I got a lot of writing done even though I was essentially doing the same thing that I always do: sit at a desk and try to write my papers—I didn’t even talk to anyone, really. I was puzzled about why a group working retreat could be more productive for someone than working on their own. As I thought about it, I came up with three hypotheses based on research on precommitment, scheduling, and work environment. I shared and explained them on Twitter (see below).