Do fat people get fat because they’re hanging out with a bunch of fatties — in other words, is it a causal relationship fostered by shared behaviors? Alternatively, do fat people initially make friends with other fat people simply because, as the study suggests, “birds of a feather flock together,” which would indicate these individuals are connecting because they were already fat in the first place?

OR, do fatties gravitate toward each other based on a biological impulse to pool information about where the best pie can be had in their local community? (OK, I made that one up.)