The pandemic shrank our social circles. Let's keep it that way.

Research by Robin Dunbar, an evolutionary psychologist, shows that human beings have the cognitive capacity to accommodate only four to six close friends. These are the people in the top tier of your social network, for whom you have the greatest affinity and affection and who require daily or weekly interactions to maintain. Included in that group is typically your romantic partner and maybe a couple of family members. Lower in the hierarchy are friends in whom you invest progressively less of your attention, and therefore your ties become more tenuous. Without some degree of regular contact, these second- and third-tier friends can fall into the realm of acquaintance. Given that we have limited time and emotional energy, social networks are a zero-sum game. Add a friend, and another one inevitably drops in the ranking. “Sometimes you fall out with people, or you just find somebody else to substitute in that slot,” Dr. Dunbar said. “The pandemic is likely sharpening the decisions we make about who we really like and dropping those who we like if there’s nobody else.” All those incidental or convenient friends have likely evaporated, and you’re left to ponder who is actually important to you.