Not so different from the techniques of medical researchers, you might argue, except that in medical studies, subjects are usually anesthetized first. Still, as monstrous as tehuacanazo sounds, ir's simply a variation on ancient traditions. Pre-conquest Indians of Mexico punished their children by forcing them to breathe the smoke of roasting chiles. And they punished sex crimes by nubbing crushed chiles on the offending parts of the anatomy. Chiles' functions as a medicine and a tool for molding behavior don't end the list of possible uses.
Farmers sometimes add byproducts of mild chiles to chickenfeed to make yolks a brighter yellow.
Doing the same to a canary's food can make the bird's feathers tum yellower. Colors extracted from chiles brighten lipsticks, sausages, and salad dressings. Read the fine print on a can of commercial antiartacker spray, and you may discover it's one of the brands that use capsaicinoids as the active ingredient. For centuries people have used chiles in place of cash. In pre-Columbian Mexico, Indians paid their taxes in chiles.