Appeared in the December, 2001, American Psychological Society Observer
"Freedom and fear are at war," President Bush has told us. The terrorists' goal, he says, is "not only to kill and maim and destroy" but to frighten us into inaction.1
Alas, the terrorists have made progress in their fear war, by diverting our anxieties from big risks toward smaller risks. Flying is a case in point.
Even before the horrors of September 11th and the ensuing crash at Rockaway Beach, 44 percent of those willing to risk flying told Gallup they felt fearful.2 "Every time I get off a plane, I view it as a failed suicide attempt," movie director Barry Sonnenfeld has said.3 After the five crashed airliners, and with threats of more terror to come, cancellations understandably left airlines, travel agencies, and holiday hotels flying into the red.
Indeed, the terrorists may still be killing us, in ways unnoticed. If we now fly 20 percent less and instead drive half those unflown miles, we will spend 2 percent more time in motor vehicles.4 This translates into 800 more people dying as passengers and pedestrians.5 So, in just the next year the terrorists may indirectly kill three times more people on our highways than died on those four fated planes.
Ah, but won't we have spared some of those folks fiery plane crashes? Likely not many, especially now with heightened security, hardened cockpit doors, more reactive passengers, and the likelihood that future terrorists will hit us where we're not looking. National Safety Council data reveal that in the last half of the 1990s Americans were, mile for mile, 37 times more likely to die in a vehicle crash than on a commercial flight.6 When I fly to New York, the most dangerous part of my journey is the drive to the Grand Rapids airport. (My highway risk may be muted by my not drinking and driving, but I'm still vulnerable to others who do.)
Or consider this: From 1990 through 2000 there were 1.4 deaths per 10 million passengers on U.S. scheduled airlines.7 Flying understandably feels dangerous. But we have actually been less likely to crash and die on any flight than, when coin tossing, to flip 22 heads in a row.8
Will yesterday's safety statistics predict the future? Even if not, terrorists could take down 50 more planes with 60 passengers each and-if we kept flying-we'd still have been safer this year in planes than on the road.9 Flying may be scary, but driving the same distance should be many times scarier.
Why do we fear the wrong things? Why do so many smokers (whose habit shortens their lives, on average, by about five years) fret before flying (which, averaged across people, shortens life by one day)? Why do we fear terrorism more than accidents-which kill nearly as many per week in just the United States as did terrorism with its 2,527 worldwide deaths in all of the 1990s?10
Psychological science has identified four influences on our intuitions about risk. First, we fear what our ancestral history has prepared us to fear. Human emotions were road tested in the Stone Age. Yesterday's risks prepare us to fear snakes, lizards, and spiders, although all three combined now kill only a dozen Americans a year.11 Flying may be far safer than biking, but our biological past predisposes us to fear confinement and heights, and therefore flying.
Second, we fear what we cannot control. Skiing, by one estimate, poses 1000 times the health and injury risk of food preservatives.12 Yet many people gladly assume the risk of skiing, which they control, but avoid preservatives. Driving we control, flying we do not. "We are loathe to let others do unto us what we happily do to ourselves," noted risk analyst Chauncey Starr.13
Third, we fear what's immediate. Teens are indifferent to smoking's toxicity because they live more for the present than the distant future. Much of the plane's threat is telescoped into the moments of takeoff and landing, while the dangers of driving are diffused across many moments to come, each trivially dangerous.
Fourth, we fear what's most readily available in memory. Horrific images of a DC-10 catapulting across the Sioux City runway, or the Concorde exploding in Paris, or of United Flight 175 slicing into the World Trade Center, form indelible memories. And availability in memory provides our intuitive rule-of-thumb for judging risks. Small wonder that most of us perceive accidents as more lethal than strokes, and homicide as more lethal than diabetes. (In actuality, the Grim Reaper snatches twice as many lives by stroke as by accident and four times as many by diabetes as by homicide.14)
Thousands of safe car trips (for those who've survived to read this) have extinguished our initial anxieties about driving. In less familiar realms, vivid, memorable images dominate our fears. We can know that unprovoked great white shark attacks have claimed merely 67 lives worldwide since 1876.15 Yet after watching Jaws and reading vivid accounts of last summer's Atlantic coastal shark attacks, we may feel chills when an underwater object brushes our leg. A thousand massively publicized anthrax victims would similarly rivet our attention more than yet another 20,000+ annual influenza fatalities, or than another 30,000+ suicidal, homicidal, and accidental gun deaths.16
As publicized Powerball lottery winners cause us to overestimate the infinitesimal odds of lottery success, so vivid airline casualties cause us to overestimate the infinitesimal odds of a lethal airline ticket. We comprehend Maria Grasso's winning $197 million in a 1999 Powerball lottery. We don't comprehend the 328 million losing tickets enabling her jackpot. We comprehend the 266 passengers and crew on those four fated flights. We don't comprehend the vast numbers of accident-free flights-16 million consecutive fatality-free takeoffs and landings during one stretch of the 1990s.17 Dramatic outcomes capture our attention; probabilities we hardly grasp. The result: We overvalue lottery tickets, overestimate flight risk, and underestimate the dangers of driving.
The moral: It's perfectly normal to fear purposeful violence from those who hate us. But with our emotions now calming a bit, perhaps it's time to check our fears against facts. "It's time to get back to life," said terror-victim widow Lisa Beamer before boarding the same flight her husband had taken on September 11th.18 To be prudent is to be mindful of the realities of how humans die. By so doing, we can take away the terrorists' most omnipresent weapon: exaggerated fear.
And when terrorists strike again, remember the odds. If, God forbid, anthrax or truck bombs kill a thousand Americans, we will all recoil in horror. Small comfort, perhaps, but the odds are 284,000 to 1 that you won't be among them.
1. Bush: First quote was from his address to the joint session of Congress, the second from his October 11th news conference.
2. "Commercial Aviation," Gallup Report, March/April, 1989, pp. 32-33.
3. Barry Sonnenfeld: Quoted by J. Winokur, "Curmudgeon," Funny Times, August, 2001, p. 4.
4. We drove 3,411 billion miles in the most recent year (1995) for which Statistical Abstract of the United States provides data. Last year we flew 692 billion miles. An additional 69 billion miles driven instead of flown would add 2 percent to our 3.4 billion miles driven. Air traffic data are available from the Air Transport Association at www.airlines.org
5. Some 40,000 vehicle-related deaths per year x .02 = 800. Vehicle accidents includes cars, truck, and motorcycles and both passengers and pedestrians.
6. Data from 1995 to 1999 summarized for me by Kevin T. Fearn of the National Safety Council's Research and Statistics Department. Several years ago I independently analyzed data from the decade of the 1980s and found that commercial flights were 26 times safer per passenger mile.
7. I computed these data by averaging passenger fatalities per million passengers from the 11 years from 1990 to 2000 (data available from the Air Transport Association at www.airlines.org as "Safety History of U.S. Scheduled Airlines").
8. The odds of heads on a first coin flip are 1 in 2. The odds of two consecutive heads are 1 in 4. The odds of 22 consecutive heads are 1 in 4,194,304. By comparison 1.4 deaths per 10 million represent 1 in 7.1 million.
9. Details of calculation: The Air Transport Association reports that 483 passengers were killed in plane crashes from 1995-1999 (97 per year). During these years, the National Safety Council's Research and Statistics Department tells me, we were 37 times safer per passenger mile in planes than motor vehicles. Multiplying 37 x 97 we can estimate that nearly 3600 people would have to die in plane crashes during an average year for flying to be as dangerous as cars, trucks, and motorcycles. (I'm not sure how many people will have died in nonterrorist plane crashes this year, but I suspect it will end up as fewer than 100, as in the prior four years. So the remaining 3500+ would have to come from terrorist crashes. Dividing 3500 by 60 passengers yields 58 planes like those on 9-11 that would need to crash for flying to equal the dangers of driving.) My estimate of 60 passengers per plane did not count crew members.
10. Global terrorism claimed 2,527 lives during the 1990s, reports the U.S. State Department (L. C. Johnson, "The Declining Terrorist Threat," New York Times, July 10, 2001).
11. National Safety Council: 35 deaths from venomous snakes, lizards, and spiders from 1994 through 1996, as reported in "Injury Facts" (www.nsc.org/lrs/statinfo/99016.htm).
12. Skiing versus preservatives: P. Slovic, "Perception of Risk," Science 236 (1987): 280-285.
13. Chauncey Starr: "Social Benefit versus Technological Risk," Science 165 (1969): 1232-1238.
14. Accident data: Statistical Abstract of the United States.
15. 67 fatalities: According to the International Shark Attack File at the Florida Museum of Natural History, as reported by T. McCarthy, "Why Can't we be Friends?," Time, July 30, 2001, pp. 34-41.
16. 20,000+ influenza fatalities: http://www.cdc.gov/od/oc/media/transcripts/t011031.htm.
30,000+ firearm fatalities: www.bradycampaign.org/facts/research/firefacts.asp.
Over the last 30 years, roughly 1 million Americans have been killed by firearms.
17. 16 million flights: M. Tolchin, "Major Airlines go Two Years without a Fatality," New York Times report in Grand Rapids [Mich.] Press, April 17, 1994, p. A10.
18. Lisa Beamer: Widely quoted, as in Time, October 29, 2001, p. 17.
Hope College social psychologist David G. Myers is author of Intuition: Its Powers and Perils, Yale University Press, 2002.