Quick question: Does your mouth fill to the brim with saliva when a big bucket of fried chicken is plopped down in front of you? How about potato chips? Pork rinds? Follow up query: Do your eyes roll back into your skull with pleasure every time a crunching sound is emitted from your mouth? Is each and every audible moan from your lips punctuated by short little yips that scream to the world, “I love what’s going on here!” Well, great news: You’re normal. I mean, not entirely normal, but normal enough. Humankind's obsession with crispy food goes way back, and we actually have our early ancestors to thank for our love of pretzels, pork rinds, and crispy bacon. 

To get to the bottom of this pseudo-mystery, I talked to John S. Allen, research scientist at the University of Southern California an author, who was happy to discuss our love of crispy food. Allen wrote a whole book on the way humans eat and how we’re actually hardwired to go nuts over stuff like, say, popcorn or those gross little kale chips you find at healthy food stores. 

Allen shows us that the answer lies—like so many of our idiosyncrasies—in the hands of our ancestors. It all started with hunting and gathering.

“Sometime between one or two million years ago, our ancestors started to make and use fire to cook food. This made available to them a whole new world of energy-rich foods to eat. Cooking introduced a different, ‘unnatural,’ source of crispy foods (e.g., the crust of meat) and gave the nutritional bonanza that cooking provided our ancestors, it was very useful for our ancestors to be attracted to cooked and crispy food.” 

Are you with us so far? Fire = good.

Allen goes on to say that the jones for crispy food gave these two-legged apes (his words, not mine) a reason to seek out more crispy food, thus creating an everlasting cycle of seek and crust. In fact, we can actually pinpoint the development of our large brains on the development of fire. Evolution rules! 

Allen continues, “Looking way back in our evolutionary past, the primary crispy foods that were available to us, or our ancestral kind, were insects and parts of plants. In general, our ape-ish ancestors would have preferred fruits or a bit of chewable meat from a small animal (e.g. organs, brain) and things that were not particularly crispy. But when these kinds of foods were not readily available, they had to rely on less nutritious, less palatable ‘fallback foods,’ such as insects and the tougher parts of plants.” That’s right, our ancestors considered crispy food to be a Plan B, which is so unlike us. According to Allen, the attraction to crispy food was purely for survival. 

But what about modern day crispy foods? When did eating food with a crunch become less about “If I don’t eat this, I’m gonna die” to “If you eat the last potato chip, I’m going to kill you”? 

“One reason why crispy foods might be appealing on a more personal level is that crispy/crunchy adds a whole new sensory quality to a food, beyond taste,” Allen says. “When we eat a lot of one food, there is a tendency to habituate to its flavor, making it less and less palatable as we consume it. With a crunchy food, the sensory experience encompasses sound as well as taste.” Enter the audible moans and short yips I mentioned earlier. What he’s basically implying is that eating crunchy food produces an orchestra in our brain that’s playing, like, every one of your favorite songs at the same time. When we hear that, the party is complete: Taste and sound in one bite is amazing to our brains. 

Allen finishes up his point by explaining that “people don't think of eating a bowl of potato chips or popcorn as being a complex sensory experience, [but] sound does play a large and satisfying role in the eating experience of these foods.” 

So, in a way, a lot of it is about sound—along with evolution, genes, and all that good stuff. When asked about his favorite food, Allen quickly answered: “Fried chicken all the way!” 

A man after my own heart. And probably yours, too.