What a fascinating field study of the malevolent it would be; though I suspect they would be utterly boring in their ordinariness.
I wish I could follow these people around with cameras all day long. I want to know everything about them. I want to know what they do every day, how they talk to each other, how they spend their free time, where they vacation. I want to know what kinds of human beings are comfortable behaving this monstrously. Do they look like monsters? It’s hard not to picture them as monsters.
Because weird, antisocial behavior is interesting to me I poked around and found a whole Allergic Living piece from 2010 with anecdotes of relatives sneak feeding allergens.
Affirming group membership by eating the same thing must be deep in humans.