People were happier and felt greater belonging on days with more weak-tie interactions. A brief genuine exchange with a barista produced more positive affect than an efficient one, and the effect was mediated by belonging.
How it was done
Daily diary studies of weak-tie interactions, plus a field experiment in which people were assigned to have either a genuine or a purely efficient exchange with a barista.
What it means
It widens the set of relationships worth attending to beyond the closest handful. The people at the edge of a network are doing more than they appear to.
It also fits the classroom exposure work: simply being repeatedly present, without conversation, substantially increased how much people were liked. Low-effort presence returns more than it feels like it does.
The caution is that a wider circle is exactly where a tool like this could slide into networking, which the communal-versus-exchange literature says is where it would start doing damage.