PULLMAN, Wash.—Some of the world's nastiest behavior grows out of spite, the dark art of hurting an opponent even when it comes at a price to yourself.
Divorcing couples often go out of their way to hurt each other and even their kids, skirting the more peaceful path to moving on.
Tax evaders can grow so vengeful over a penalty that they'll double down on their cheating.
Terrorists can be so keen to hurt their enemies, they commit suicide in the process.