No one is more susceptible to an expert’s fearmongering than a parent. Fear is in fact a major component of the act of parenting. A parent, after all, is the steward of another creature’s life, a creature who in the beginning is more helpless than the newborn of nearly any other species. This leads a lot of parents to spend a lot of their parenting energy simply being scared.

The problem is that they are often scared of the wrong things. It’s not their fault, really. Separating facts from rumors is always hard work, especially for a busy parent. And the white noise generated by the experts—to say nothing of the pressure exerted by fellow parents—is so overwhelming that they can barely think for themselves. The facts they do manage to glean have usually been varnished or exaggerated or otherwise taken out of context to serve an agenda that isn’t their own.

Consider the parents of an eight-year-old girl named, say, Molly. Her two best friends, Amy and Imani, each live nearby. Molly’s parents know that Amy’s parents keep a gun in their house, so they have forbidden Molly to play there. Instead, Molly spends a lot of time at Imani’s house, which has a swimming pool in the backyard. Molly’s parents feel good about having made such a smart choice to protect their daughter.

But according to the data, their choice isn’t smart at all. In a given year, there is one drowning of a child for every 11,000 residential pools in the United States. (In a country with 6 million pools, this means that roughly 550 children under the age of ten drown each year.) Meanwhile, there is 1 child killed by a gun for every 1 million-plus guns. (In a country with an estimated 200 million guns, this means that roughly 175 children under ten die each year from guns.) The likelihood of death by pool (1 in 11,000) versus death by gun (1 in 1 million-plus) isn’t even close: Molly is roughly 100 times more likely to die in a swimming accident at Imani’s house than in gunplay at Amy’s.

But most of us are, like Molly’s parents, terrible risk assessors. Peter Sandman, a self-described “risk communications consultant” in Princeton, New Jersey, made this point in early 2004 after a single case of mad-cow disease in the United States prompted an antibeef frenzy. “The basic reality,” Sandman told the New York Times, “is that the risks that scare people and the risks that kill people are very different.”

Sandman offered a comparison between mad-cow disease (a super-scary but exceedingly rare threat) and the spread of food-borne pathogens in the average home kitchen (exceedingly common but somehow not very scary). “Risks that you control are much less a source of outrage than risks that are out of your control,” Sandman said. “In the case of mad-cow, it feels like it’s beyond my control. I can’t tell if my meat has prions in it or not. I can’t see it, I can’t smell it. Whereas dirt in my own kitchen is very much in my own control. I can clean my sponges. I can clean the floor.”

Sandman’s “control” principle might also explain why most people are more scared of flying in an airplane than driving a car. Their thinking goes like this: since I control the car, I am the one keeping myself safe; since I have no control of the airplane, I am at the mercy of myriad external factors.

So which should we actually fear more, flying or driving?

It might first help to ask a more basic question: what, exactly, are we afraid of? Death, presumably. But the fear of death needs to be narrowed down. Of course we all know that we are bound to die, and we might worry about it casually. But if you are told that you have a 10 percent chance of dying within the next year, you might worry a lot more, perhaps even choosing to live your life differently. And if you are told that you have 10 percent chance of dying within the next minute, you’ll probably panic. So it’s the imminent possibility of death that drives the fear—which means that the most sensible way to calculate fear of death would be to think about it on a per-hour basis.

If you are taking a trip and have the choice of driving or flying, you might wish to consider the per-hour death rate of driving versus flying. It is true that many more people die in the United States each year in motor vehicle accidents (roughly forty thousand) than in airplane crashes (fewer than one thousand). But it’s also true that most people spend a lot more time in cars than in airplanes. (More people die even in boating accidents each year than in airplane crashes; as we saw with swimming pools versus guns, water is a lot more dangerous than most people think.) The per-hour death rate of driving versus flying, however, is about equal. The two contraptions are equally likely (or, in truth, unlikely) to lead to death.

But fear best thrives in the present tense. That is why experts rely on it; in a world that is increasingly impatient with long-term processes, fear is a potent short-term play. Imagine that you are a government official charged with procuring the funds to fight one of two proven killers: terrorist attacks and heart disease. Which cause do you think the members of Congress will open up the coffers for? The likelihood of any given person being killed in a terrorist attack are infinitesimally smaller than the likelihood that the same person will clog up his arteries with fatty food and die of heart disease. But a terrorist attack happens now; death by heart disease is some distant, quiet catastrophe. Terrorist acts lie beyond our control; french fries do not. Just as important as the control factor is what Peter Sandman calls the dread factor. Death by terrorist attack (or mad-cow disease) is considered wholly dreadful; death by heart disease is, for some reason, not.

Sandman is an expert who works both sides of the aisle. One day he might help a group of environmentalists expose a public health hazard. His client the next day could be a fast-food CEO trying to deal with an E. coli outbreak. Sandman has reduced his expertise to a tidy equation: Risk = hazard + outrage. For the CEO with the bad hamburger meat, Sandman engages in “outrage reduction”; for the environmentalists, it’s “outrage increase.”

Note that Sandman addresses the outrage but not the hazard itself. He concedes that outrage and hazard do not carry equal weight in his risk equation. “When hazard is high and outrage is low, people underreact,” he says. “And when hazard is low and outrage is high, they overreact.”

So why is a swimming pool less frightening than a gun? The thought of a child being shot through the chest with a neighbor’s gun is gruesome, dramatic, horrifying—in a word, outrageous. Swimming pools do not inspire outrage. This is due in part to the familiarity factor. Just as most people spend more time in cars than in airplanes, most of us have a lot more experience swimming in pools than shooting guns. But it takes only about thirty seconds for a child to drown, and it often happens noiselessly. An infant can drown in water as shallow as a few inches. The steps to prevent drowning, meanwhile, are pretty straightforward: a watchful adult, a fence around the pool, a locked back door so a toddler doesn’t slip outside unnoticed.

If every parent followed these precautions, the lives of perhaps four hundred young children could be saved each year. That would outnumber the lives saved by two of the most widely promoted inventions in recent memory: safer cribs and child car seats. The data show that car seats are, at best, nominally helpful. It is certainly safer to keep a child in the rear seat than sitting on a lap in the front seat, where in the event of an accident he essentially becomes a projectile. But the safety to be gained here is from preventing the kids from riding shotgun, not from strapping them into a $200 car seat. Nevertheless, many parents so magnify the benefit of a car seat that they trek to the local police station or firehouse to have it installed just right. Theirs is a gesture of love, surely, but also a gesture of what might be called obsessive parenting. (Obsessive parents know who they are and are generally proud of the fact; non-obsessive parents also know who the obsessives are and tend to snicker at them.)