"Prepping," or getting ready to live without societal support, is apparently a largely American activity, and a recent one. Companies that cater to people who want to be self-reliant for food, water, and power have grown their revenue by about 700 percent over the last decade, and prepper products are now offered in places like Costco, Kmart, and Bed Bath & Beyond.

But it's not at all clear what's driving this growth—why are more people getting ready for society's collapse? Some explanations focus on a tendency toward paranoia in American society or fears of terrorism or natural disaster. But actual evidence that directly supports any of these ideas as the main reason is pretty sparse.

So Michael Mills at the UK's University of Kent decided to correct this gap in our knowledge. Mills went on an American road trip, spending time talking to (and butchering animals with) 39 preppers in 18 different US states. Rather than rampant paranoia, Mills suggests, preppers are motivated by non stop media coverage of natural disasters, as well as a government that encourages them to prepare for the worst.

The sum of all fears

To the extent that one exists, the public image of a prepper is of someone who's getting ready for the collapse of society, at which point money and electric grids, along with all the things that depend on them, will become unavailable. Preppers are ready to purify water to drink, hunt and butcher for meals, and scare off anyone who tries to get a piece of their post-apocalyptic bliss, possibly via gunfire. There may be bunkers involved.

But that image is fostered in part by the public's biggest route to being made aware of preppers: Doomsday Preppers, which aired on the National Geographic channel. (The show has also infiltrated the academic literature, as Mills cites a study that analyzed the psychology of people who appeared on the show.) Although Mills doesn't explicitly say it, it's reasonable to wonder whether one can get an accurate cross-section of the prepper community purely from watching people who were chosen to appear on the show based on whether they make for good television.

To find out, Mills placed ads on some popular prepper websites, recruited his cohort, and started his road trip. His goal wasn't a quantitative study; it was ethnography, which is largely talking to people, spending time with them, and seeing whether there are commonalities in how they think. It's important to note that regardless of how popular these prepper sites are, they probably won't produce a full cross-section of the prepper community, either, nor will selecting people based on willingness to talk to a researcher. That said, you'll still probably get more depth than you would by selecting for great TV.

In fact, one of the subjects specifically told Mills that "it’s not like on [National Geographic’s] Doomsday Preppers." They weren't preparing for the total collapse of society. They were getting ready to deal with a local collapse of services that might last a few months. It's less Armageddon and more Hurricane Irma—which hadn't hit yet while Mills was doing his interviews but has since suggested that preparing for a couple of months without key services may be badly underestimating needs. Prepper supplies would typically be enough to only hold out that long, and Mills said they often referred to these caches as "more than they'd ever need."

Another key difference is that the preppers didn't have any specific expectations for a particular disaster that's likely to happen. Some of them lived in flood-prone areas but would invariably mention additional fears like terrorism or outbreaks of new diseases. And for many of them, those risks didn't produce a sense that disaster was inevitable. Preparing was more a just-in-case activity. As Mills concluded, "Their concerns tend to emerge in response to numerous disaster risks that are widely reported and recognized in wider American culture."

Media and government

Tornadoes, hurricanes, fires, earthquakes—there are few areas of the country with no natural disaster risks, and terrorism and disease outbreaks could happen nearly anywhere. So what factors drive some people to respond to those risks by being ready to do without both private and government services or any sort of emergency support?

One factor, Mills argues, is that the organizations responsible for coordinating that emergency support tell them they should be ready to deal without it. "Federal agencies have recently encouraged American citizens to contemplate surviving disasters without their assistance," Mills writes, citing a previous study. And the government also warns people to be ready for risks that have never materialized. Since 2003, a group within the Department of Homeland Security has advocated that people "have a ‘safe room’, duct tape, and plastic sheets on-hand to secure their home against (unprecedented) chemical terrorist attacks."

A second motivation comes from the media, which tends to provide nonstop coverage of natural disasters and their aftermath. Mills said nearly every subject mentioned Hurricane Katrina, Hurricane Sandy, or both. Mills' road trip took place in 2014, and Ebola and ISIS both made frequent appearances in the risks mentioned by the preppers (as they might again today).

His conclusion, then, is that preppers are responding to what they're hearing: "prepping is a phenomenon with clear, previously unacknowledged links to broader risk communications and concerns in the twenty-first century United States." In other words, prepping might be an unusual response to the challenges everyone faces when trying to communicate risks to the public, but it's on a spectrum of responses, rather than being a distinct phenomenon.

That, as Mills notes, still leaves a couple of key questions, like why the response is so prevalent in the US, and why plenty of US citizens face the same risks but can't even be bothered to store some jugs of water or pack a go-bag.