Chili peppers. By Ed Salkeld, Creative Commons.

Ed Note: My SciAm colleagues Bora Zivkovic and Jason Goldman recently re-posted their excellent discussions on our mad affair with peppers. As Jason rightly notes, pepper—in the form of pepper spray—has been in the news much of late and people are horrified at its potential to hurt. Yet, it's a food item that many people can't get enough of. This post add historical and psychological notes on our pepper-cravings. It was originally posted on July 22, 2010 and is presented here with slight edits.

Why do some like what hot? Well, peanuts, of course. Spicy peanuts What did you think I was talking about? Spicy peanuts, and really, all sorts of spicy foods. Why do some people like and prefer spicy foods to the point where they consume mouth scorching dishes—and ask for more? This was the question posed to me by a coworker, as he reached for the can of spicy peanuts sitting in the communal kitchen area at work. The peanuts are roasted with Habanero peppers and then dusted with those scorchers for good measure. They're hot for my coworkers, except for the one who found himself snacking throughout the day. I think they're tingly. But then again, I have a different cultural background when it comes to spicy foods than most of my coworkers: As a Trinidadian, spice is a part of my heritage. And yet, my peanut-eating coworker who posed the question is Irish. (He did grow up in Texas, so perhaps that explains his tolerance for spice? He's not sure himself.) But pepper has an unusual relationship with people all around the world.

I grew up in a household where pepper sauce—literally a blending of peppers with slight additional seasoning—is a condiment for everything, so my sense of spiciness is admittedly skewed. In short, I like everything hot. In the early days of our marriage, S brought one of his cousins home for dinner. They requested a Trinidadian dish. I was hesitant to make anything elaborate because I was a new cook, and I wanted to make a good first impression. I wracked my brain for something that (a) would be identifiable as "Trinidadian" and that (b) I wouldn't burn. (I have since become a much better cook.) The answer was simple: Aloo pies. Aloo pies are fried dough pockets stuffed with a potato filling that you make to suit your tastes. They seem to be distantly related to Indian samosas—at least that's what I thought the first time I had a samosa, and that was the way I introduced samosas to my eat-anything-just-tell-me-what-it-is father. The primary difference between the two is that samosas look a little like a ball whereas Aloo pies are flat. Anyway, I was trying to be a good hostess—which is why I roasted a Scotch bonnet pepper (a relative of the Habanero) on the stove (which increases the heat) and then mashed it in with the potato filling (which makes things even hotter).

Dinner was a very teary affair. It was good; the guys couldn't get enough. But they'd never eaten anything so hot in their lives. The beer they had bought quickly disappeared, tears streamed down their face, their noses ran, and still they ate. I have never made Aloo pies like that again (partly because getting hot Scotch bonnets isn't as easy for me anymore, and partly because I am seriously surprised I didn't land one of them in the ER). And they still talk about it.

Habaneros are members of the Chili pepper family, which are native to the Americas. However, pepper has a lengthy history. Black pepper, a fairly common item in most kitchens, has been widely traded for a long time, and was once prized enough to serve as a form of currency. Black peppers

  • are native to India and have been used in Indian cooking since 2000 BC,
  • were found in the nostrils of Ramsess II,
  • and appear in Greece in the 4th century BC, but only the wealthy were able to afford them.

By 30 BC, Roman trade had spread black pepper widely. The pepper trade route the Romans established would last almost a millennium. When Rome fell, the attacking hordes demanded ransoms amounting to tons of pepper. The lucrative pepper trade would fall into the hands of the Arabs, who could charge hefty taxes for western bound trade. Not wanting to be subject to the taxes of non-Christian powers, Western Europeans worked to seize the trade route. This motivation is partly credited with the expansion that followed as countries sought more direct trade routes with India. From the 8th to the 15th centuries the Republic of Venice was a main player in the Eastern spice trade. However, when the Byzantine Empire fell to the Ottomans in 1453 and the trade was controlled by the Turks, the old motivations resurfaced, spurring the quest for a direct route to India once again. Columbus and Vasco da Gama added the New World varieties of pepper to the spice trade: the Habanero chili, and its derivative, the Scotch Bonnet pepper.

So we have a sense for how my Irish coworker and I can share a fondness for spicy foods: the relentless spread of the spice throughout the world means that many cultures have encountered it. Yet, some individuals demonstrate a higher tolerance and desire for spice than others, which seems to run counter to our evolutionary design according to a popular paper by psychologist Paul Rozin.

Eating is a primary means of interacting with the world. It's necessary for survival, but according to Rozin (1997) it can be a hazardous activity as well because food items also contain toxins. Yet humans are food generalists—unlike the Koala, which will eat only eucalyptus, humans will eat just about anything. So how do we stay away from food that may be a danger to us? Well, we learn. Culture is a major factor in determining what we eat (Rozin 1997:27). We also develop taste biases:

Some omnivores, including rats and humans, have a built-in bias to like sweet tastes. This makes sense because in the real world, sweet indicates fruit, and hence carbohydrates, a source of energy. We also have a built-in avoidance of bitter tastes, which also makes sense in the real world because there is a high, although not perfect, correlation between toxic substances and bitter tastes (Rozin 1997: 29)

Is pepper preference an anomaly then? Generalists are faced with dilemmas every day. They are always at risk for consuming toxins, but they need to expand their supply: "Having a wide range of foods provides protection against the disappearance of one food source or the appearance of another species that is better adapted to exploit that food source (Rozin 1997: 29). So generalists tend to try new foods, though in small quantities initially to help protect against potential ill effects. This willingness to try new things combined with our preference for sweet foods has made it possible for us to tolerate bitter tastes:

The basic human liking for sweet tastes undoubtedly motivated humans to search for and cultivate sweet products such as fruits. Eventually it motivated the refining of sugar and the transporting of slaves to the Western Hemisphere in order to grow sugar ... The sweet taste, made cheap by sugar agriculture, has promoted the acceptance of otherwise difficult-to-accept foods, such as chocolate and coffee (Rozin 1997: 30).

And pepper. There is no real nutritional value to pepper, though there may be medicinal value. So why do some people eat large quantities of pepper? Rozin proposes: "They like the burn" (1997: 35). The very thing that people object to, is the reason some heap this spice on their plate. Rozin suggests that pepper allows us a chance to believe we're doing something dangerous without any real repercussions. When we bite into a pepper, our body tells us that the taste of the pepper suggests it is dangerous, even poisonous:

Humans seem to enjoy situations in which their bodies warn them of danger but they know the are really okay (1997: 36).

It lets us live dangerously for the moment. Of course, culture has a role to play as well. My cultural heritage introduced me to spicy foods from an early age and normalized it. I've read some research that suggests when spicy foods are consumed with alcohol, it enhances the effect of alcohol—which seems to be something that rum drinkers in Trinidad subscribe to. It's not uncommon for them to order a spicy plate of appetizers ("cutters") to go with their food.

Where do you stand in terms of spicy foods? How hot do you like it?


Rozin, P. (1997). Why We Eat What We Eat, and Why We Worry about It Bulletin of the American Academy of Arts and Sciences, 50 (5) DOI: 10.2307/3824612