“Having a conversation sitting next to their spouse was, to their bodies, like facing off with a saber-toothed tiger.” The Atlantic’s Emily Esfahani Smith goes in search of what makes a lasting relationship and finds that it largely comes down to kindness and generosity (which in today’s nomenclature translates into Likes and Retweets.)

+ Please take a fraction of a second and show your everlasting love (or at least like) by Liking NextDraft on Facebook.

+ Advice from 617 years of marriage.