It’s hard to know just how freaked out we’re supposed to be about Hurricane Irene. On one hand, the storm appears to be losing some steam. On the other, New York City has ordered an evacuation — for the first time in the city’s history. “This is a large, this is a deadly, this is a slow-moving hurricane that is bearing down on the state of Maryland,” Maryland Gov. Martin O’Malley said yesterday in declaring a state of emergency. “There will no doubt be a lot of flooding. Citizens should anticipate long periods of electrical outages.”

So who is going to heed these ominous warnings? There’s actually a pretty interesting body of academic research exploring what factors matter.

A 2001 study in the American Journal of Epidemiology found that having children makes a household more likely to evacuate. Pets, however, have the opposite effect. Most likely because of the challenges of animal transportation, fewer households with pets heed evacuation warnings. Those who live in mobile homes tend to be more likely to evacuate than those who do not. Watching the Weather Channel’s storm coverage tends to make people move more than a warning from a governor’s office, a 1998 paper in the Coastal Zone Management Journal found.

But how anxiety-inducing our public officials decide to make these warnings matters, too. Consider this finding from the 1993 Handbook to Emergency and Crisis Management: “Actions that increase the level of anxiety or that increase the credibility of the warning should increase the likelihood of evacuation. The practice of police asking individuals for the name of their next of kin or asking them to fill out a toe tag form might achieve the desired effect.”

Risk consultant David Roepik, writing at the New York Times’ DotEarth blog, has an interesting essay on the role psychology plays here, too. “Hurricanes are thankfully rare in the Northeast,” he writes. “The more powerful, more dangerous ones are rarer still. Few of those threatened by Irene have lost homes or property, or loved ones, or even just lost electrical power, or water, or phone/cable/Internet connections for days or weeks, the way people have in the Carolinas, Florida, the Gulf Coast states. Hurricanes in the Northeast are like earthquakes in a way — rare oddities to Twitter and text about as much as to fear.”