Calculated risks - What are the Chances?

We are notoriously bad at assessing risk. Cultural context and human psychology come into play at least as much as statistical realities. For instance, our perceptual apparatus is geared towards exotic, personal, dramatic threats. This doesn't mean we're ignorant; just human.

Newsweek magazine plunged American women into a state of near panic some years ago when it announced that the chances of a college-educated thirty-five-year-old woman finding a husband was less than her chance of being killed by a terrorist. Although Susan Faludi made mincemeat of this so-called statistic in her book Backlash, the notion that we can precisely quantify risk has a strong hold on the Western psyche. Scientists, statisticians, and policy makers attach numbers to the risk of getting breast cancer or AIDS, to flying and food additives, to getting hit by lightning or falling in the bathtub.

Yet despite (or perhaps because of) all the numbers floating around, most people are quite properly confused about risk. I know people who live happily on the San Andreas Fault and yet are afraid to ride the New York subways (and vice versa). I've known smokers who can't stand to be in the same room with a fatty steak, and women afraid of the side effects of birth control pills who have unprotected sex with strangers. Risk assessment is rarely based on purely rational considerations - even if people could agree on what those considerations were. We worry about negligible quantities of Alar in apples, yet shrug off the much higher probability of dying from smoking. We worry about flying, but not driving. We worry about getting brain cancer from cellular phones, although the link is quite tenuous. In fact, it's easy to make a statistical argument - albeit a fallacious one - that cellular phones prevent cancer, because the proportion of people with brain tumors is smaller among cell phone users than among the general population.(1)

Even simple pleasures such as eating and breathing have become suspect. Love has always been risky, and AIDS has made intimacy more perilous than ever. On the other hand, not having relationships may be riskier still. According to at least one study, the average male faces three times the threat of early death associated with not being married as he does from cancer.

Of course, risk isn't all bad. Without knowingly taking risks, no one would ever walk out the door, much less go to school, drive a car, have a baby, submit a proposal for a research grant, fall in love, or swim in the ocean. It's hard to have any fun, accomplish anything productive, or experience life without taking on risks - sometimes substantial ones. Life, after all, is a fatal disease, and the mortality rate for humans, at the end of the day, is 100 percent.

Yet, people are notoriously bad at risk assessment. I couldn't get over this feeling watching the aftermath of the crash of TWA Flight 800 and the horror it spread about flying, with the long lines at airports, the increased security measures, the stories about grieving families day after day in the newspaper, the ongoing attempt to figure out why and who and what could be done to prevent such a tragedy from happening again.

Meanwhile, tens of thousands of children die every day around the world from common causes such as malnutrition and disease. That's roughly the same as a hundred exploding jumbo jets full of children every single day. People who care more about the victims of Flight 800 aren't callous or ignorant. It's just the way our minds work. Certain kinds of tragedies make an impact; others don't. Our perceptual apparatus is geared toward threats that are exotic, personal, erratic, and dramatic. This doesn't mean we're ignorant; just human.

This skewed perception of risk has serious social consequences, however. We aim our resources at phantoms, while real hazards are ignored. Parents, for example, tend to rate drug abuse and abduction by strangers as the greatest threats to their children. Yet hundreds of times more children die each year from choking, burns, falls, drowning, and other accidents that public safety efforts generally ignore.

We spend millions to fight international terrorism and wear combat fatigues for a morning walk to protect against Lyme disease. At the same time, "we see several very major problems that have received relatively little attention," write Bernard Cohen and I-Sing Lee in Health Physics. The physicists suggest - not entirely tongue in cheek - that resources might be far more efficiently spent on programs such as government-organized computer dating services. "Favorable publicity on the advantages of marriage might be encouraged."

It's as if we incarcerated every petty criminal with zeal, while inviting mass murderers into our bedrooms. If we wanted to put the money on the real killers, we'd go after suicide, not asbestos.

Even in terms of simple dollars, our policies don't make any sense. It's well known, for example, that prenatal care for pregnant women saves enormous amounts of money - in terms of care infants need in the first year of life - and costs a pittance. Yet millions of low-income women don't get it.