Peddlers of self-help and pop-psychology are quick to assure us that we’re each our own toughest critic. In fact, it’s often our peers who will exact the harshest judgments, being best positioned to sniff out the social cues and latent hierarchies that are most legible within a shared milieu. Last year, Pete Buttigieg, the only millennial candidate in the Democratic Presidential field, failed to win the support of other members...