I often take a friend breakup harder than I do a lover breakup. Because we’re not supposed to break up with our friends. Boy- and girlfriends are practically designed to come and go, while friendship is so meaningful and precious that it makes us utter little sweet nothings like “A friend is forever” or “Friends till the end.” Nobody’s ever said “Boyfriend till the end.” Just doesn’t sound right.

So I take a little let-myself-off-the-hook comfort in this recent study showing that most friendships come with an expiration date, too. In fact, sociologists found that the seven-year-itch phenomenon applies just as much to our platonic relationships as it does our sexual ones.

During that stretch of time, as one summary put it, “personal network sizes remained stable, but many members of the network were new. Only 30 percent of  the original ‘helper’ friends and discussion partners had the same position in a subject’s network seven years later, and only 48 percent were still part of the social network.”

Perhaps we were readier to acknowledge that friendships evolve (or don’t!) as we do — and that some have a natural shelf-life — we’d be better able to take their ends in stride?