it's one of those things early man learned from animals. My birds love them but then again, birds have a dry palate and don't feel any heat from the capsacin that makes peppers hot.
FWIW, people develop an accumulative tolerance to capsacin with repeated use much like an addict develops a tolerance to a drug. You get to a point where the peppers don't taste hot any more. The you get some tastes that were previously masked by the heat. Many peppers like tabascos left to ripen on the bush are actually pretty sweet, like red bell peppers, once you aren't affected by the capsacin as much. By the way, the rest of your body develops a tolerance as well so exit points are unaffected by the capsacin as well
I always wondered who's idea was it to eat hot peppers/chiles. I mean was it stumbled upon, herbal medicine, able to eat spoiled food, just variety and just how did it get started. I ask, because you know certain chilies are HOT! and worse, the after effects can be long in coming. While I realize cooking can have something in the mix, but someone had to try it and then mix it in. What proposed a cook or for that matter an eater to go for it?
Just wondering... -----Willy