Moore, Okla., has plenty of exposure to big tornadoes. On May 20, 2013, a mile-wide twister ripped through the town, following a similar track to that of an infamous tornado that devastated Moore back in 1999. Just 11 days later, on May 31, the widest tornado ever measured in the U.S. gouged a path less than 40 miles away.

What Moore doesn’t have plenty of is basements. In the wake of this year’s storms, a local homebuilder told CNN that 15 percent or fewer of residents had any kind of underground shelter. Though central Oklahoma is one of the most tornado-prone places on Earth, basements are a rarity across the entire region. This discrepancy can’t be explained by technical issues such as soil quality or groundwater. According to geologists and engineers, it’s primarily a cultural phenomenon. Experts know why basements can save lives in a tornado, and they know how to build them. But all that information is next to useless if nobody wants a basement to begin with.

Culture has a big impact on disasters — how we prepare for them, how we respond to them and even how we could prevent them. In fact, some social scientists who study disasters say they are the result of culture — what happens when natural forces or human error come crashing into existing social systems. “Nothing is a disaster until it intersects with a specific society that has vulnerabilities that are the result of decisions made over decades … often, decisions that were made without really thinking,” says Joseph Trainor, assistant professor at the University of Delaware’s Disaster Research Center.

In Oklahoma, the tornadoes intersected with decades-old expectations about what a nice house looks like and how valuable different features are when it comes time to sell.

Most people will never experience a twister careening through their living room. It’s what Trainor calls a “low-probability, high-consequence event.” When faced with such events, we tend to focus on the low-probability part.

Most houses in the state are built as slab-on-grade — builders pour a concrete pad and construct the building on top of that. It’s a cheap way to build, much cheaper than digging down eight or 10 feet and making a basement, says Gerald Miller, a member of the Geotechnical Engineering Program faculty at the University of Oklahoma. Oklahomans have built homes this way for years, so people aren’t used to seeing basements, and builders aren’t used to making them. And residents have heard stories from older generations about how damp and leaky basements can be. Even though the technology exists to build comfortable, clean basements today, Miller says, nobody prioritizes them. Oklahomans think of basements as expensive liabilities before they think of them as potentially lifesaving shelters.

And that matches up with how humans think about risk in general. Even in “Tornado Alley” most people will never experience a twister careening through their living room. It’s what Trainor calls a “low-probability, high-consequence event.” When faced with such events, we tend to focus on the low-probability part. In the case of Oklahomans and their nonexistent basements, that means most people would choose to spend a few thousand dollars on granite countertops that will definitely improve the value of their home, rather than invest the money in a basement that could save them from a tornado that may or may not ever come. The local culture determines how the disaster plays out.

Of course, this means if you want to reduce the impact of a disaster, or stop one from happening altogether, you have to change the culture — and that can be a lot harder than implementing a technological fix.

Top-down strategies are one way to do it. Oklahoma could pass a law, for instance, mandating basements as a part of any new construction. But that kind of solution can be unpopular, especially if the public isn’t exactly clamoring for the change. Instead, Trainor says, it’s important to look at the problem as part of a larger system. Oklahoma’s lack of basements is just one aspect of a bigger question: How can we reduce the number of people who die in tornadoes?

The death toll is the real problem here, and there are lots of ways you could solve it. You could improve consumer education and make sure people understand how basements have changed over the past half century. You could change the way home builders are trained so more of them have experience building basements, which would lower the cost of construction. You could pass laws that encourage communities and neighborhoods to voluntarily build shared shelters. And you could bypass the basement issue entirely by improving tornado warning systems. Right now, Trainor says, people get, at best, a 15-minute warning of a tornado threat — and 75 percent of those end up being false alarms. If those numbers could be improved, maybe there would be fewer people in harm’s way, because they’d have more confidence in the forecast and more time to figure out how to protect themselves.

There’s not an absolute solution in that list of possibilities, and that’s kind of the point. Systems — including the cultural systems that affect how many people die in tornadoes — are complex. There are lots of different factors at work, and the real solution lies in addressing and tweaking all of them, not in bemoaning the fact that people aren’t doing something right. If we want more resilient communities, we have to start by thinking about communities as social systems and let the old idea — that individuals will make simple, rational choices based solely on what science says is good for them — blow away in the wind. View Ensia homepage