The garden grew, year by year, and led to the bottling of hot sauce, and then to my first hesitant steps into the capsaicin demi-monde. I met some pain junkies at work. I bought the T-shirt with the capsaicin molecule on it. I marveled at the uncountable number of artisanal hot sauces on the market, and at the frequency with which the words “death,” “nuclear” and “devil” were used in the names. I have to say that I drew the line at getting a capsaicin molecule tattoo. And I did not buy the T-shirt with the flaming red mouth and the legend “Pain Is Good.”

This chest-beating may be particular to the United States, where one hot sauce maker actually markets a limited edition of pure capsaicin. In places like Central America, Asia and the Indian subcontinent, hot chili peppers are an integral part of the cuisine. Only the commercial genius of American marketing could come up with a product that is marketed on the basis that you won’t be able to use it.

End of Life Hot Sauce! So Painful You Will Die! Visa, MasterCard, Discover or PayPal accepted. Well, darn, sign me up for that.

How did this happen? The story of how chilies got their heat is pretty straightforward. A recent study suggested that capsaicin is an effective defense against a fungus that attacks chili seeds. In fact, experiments have shown that the same species of wild chili plant produces a lot of capsaicin in an environment where the fungus is likely to grow, and very little in drier areas where the fungus is not a danger.

The fact that capsaicin causes pain to mammals seems to be accidental. There’s no evolutionary percentage in preventing animals from eating the peppers, which fall off the plant when ripe. Birds, which also eat fruits, don’t have the same biochemical pain pathway, so they don’t suffer at all from capsaicin. But in mammals it stimulates the very same pain receptors that respond to actual heat. Chili pungency is not technically a taste; it is the sensation of burning, mediated by the same mechanism that would let you know that someone had set your tongue on fire.

But humans took to them quickly. There is evidence that by 6,000 years ago domesticated Capsicums (hot peppers) were being used from the Bahamas to the Andes. Once Columbus brought them back from the New World chilies spread through Europe, Asia and Africa. Jean Andrews, in the classic “Peppers: The Domesticated Capsicums” (in which she made the comment above about pepper competitions and being burned at the stake), tracks the spread of peppers by early writers. By the mid-1500s, they were known in Europe, Africa, India and China.

No one knows for sure why humans would find pleasure in pain, but Dr. Rozin suggests that there’s a thrill, similar to the fun of riding a roller coaster. “Humans and only humans get to enjoy events that are innately negative, that produce emotions or feelings that we are programmed to avoid when we come to realize that they are actually not threats,” he said. “Mind over body. My body thinks I’m in trouble, but I know I’m not.” And it says, hand me another jalapeño.