The decision

Here's the rule. A friend's message gets two lines today, and I don't owe a better one.

That's it. It isn't a rule about being a better friend, or about having more friends, or about calls and visits, which follow from it but aren't it. It's a rule about the reply. When a message arrives, the default used to be the meaning-to. Now the default is two lines from wherever you are, and the proper reply is retired, because it never existed.

Three when-then plans, which are a form the research on planning supports, a specific situation paired with a specific act, so the act doesn't need deciding in the moment.

When I read a friend's message, then I reply in two lines before I put the phone down, and if I can't, I leave it unread until I can.

When I catch myself typing "sorry for the slow reply" or "I've been meaning to", then I delete it and start with the thing they sent.

When I think "it's their turn" or "it's been too long", then I take that as the sign that it's mine, and I send the line without news.

What to expect, and this is my expectation and not a finding. The first week the replies feel thin and you'll want to add a third line. Don't. The second week the list is clear for the first time in years and stays clear, because a message that's answered on arrival never gets a stretch. Somewhere in the second month replying on arrival stops being a decision and becomes what happens, which is what Phillippa Lally and colleagues found in a study of everyday habits, where a daily behaviour in a fixed setting became automatic over weeks and a missed day didn't undo it. You'll get more messages, because people send them to those who answer. You'll get invited earlier. Two or three friends from the thinned list will be back in your week, not through any big effort but because the door was answered and the third message named a date. And the Sunday feeling will be gone, which you'll notice one Sunday and not think much about, which is the point.

The rule doesn't ask you to be warmer than you are. You were always warm. It asks you to let the warmth arrive, in the size it fits in, on the day it happens, and to stop holding it back for a version that does the friend justice, because the friend never wanted justice. They wanted to hear from you.