Freud observed that people who have much in common can still fight bitterly because they grow overly sensitive to the disagreements remaining between them. He called this the “narcissism of small differences”: “It is precisely the minor differences in people who are otherwise alike that form the basis of feelings of hostility between them.”

In Gulliver’s Travels, 11,000 people die in a war between the Big-endians, who break their eggs at the big end, and the Little-endians, who break them at the little end. A Lilliputian admiral attacks Gulliver because “he had good reasons to think you were a Big-endian in your heart; and, as treason begins in the heart, before it appears in overt acts, so he accused you as a traitor on that account, and therefore insisted you should be put to death.”