Ask the name of the villain in the Harry Potter saga, and almost everyone will answer Lord Voldemort. But as a social scientist who studies group dynamics, I see a far more pernicious villain: the Sorting Hat.
When placed upon the heads of aspiring eleven-year-old magic-users, the Sorting Hat assigns each student to one of four “houses.” Each house has strong distinguishing traits—the brave are separated from the brainy, the loyal from the devious. Uniforms mark students’ house memberships wherever they go. The houses compete against one another in almost every aspect of school life. Students root against, and often vilify, those from other houses while supporting their own. Over the course of seven thick books, no one ever leaves the house to which the Sorting Hat assigned them. Nor does anyone seek to dispose of the hat and its sinister grouping, despite the clear role it plays in drawing the dividing lines for the wars that bookend the story.
The Sorting Hat can remain a hidden villain because it seems so familiar in our world. We don’t need magical headwear to sort people. Our brains do it for us. You carry an inner sorting hat with you wherever you go. Human society is built on sorting ourselves and others into groups. We sort people based on broad characteristics like nationality, politics, and gender. We also sort people into smaller, tight-knit groups, such as family, friends, a work team, a sports team, or a band.
We are collective creatures. Our memberships in ever-shifting, overlapping groups govern our experience of the world. Many of us wake up among family or roommates but then go to work and behave quite differently among our coworkers. After work, we may meet up with friends and think and act differently again. We may spontaneously stumble into a group for a few minutes, like a street performer’s audience or a disgruntled group of stranded commuters waiting on a delayed subway train. In each situation, we think and behave differently because of how we believe we fit
within that group.
Understanding human behaviour means understanding group dynamics—the obvious and hidden ways in which our thoughts, feelings, and behaviours are shaped by groups. In nearly every moment of our lives, we feel the pull of groups whispering to us to conform to the unspoken rules of being among other humans. In the street performer’s audience, we clap when others clap and feel the swell of others’ enjoyment. Without even realising it, we conform to avoid standing out, applauding along even when we’re privately unimpressed. We compete for acclaim from our fellow group members at work and at home, and when outsiders threaten them, we defend our collectives as if they were part of ourselves. Taken to extremes, our inner sorting hats have guided humanity’s greatest accomplishments . . . and our greatest evils.
Colin M. Fisher's The Collective Edge: Unlocking the Secret Power of Groups is our Welldoing Book of the Month for August 2025.
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