Speeding car Volvo introduced the three-point seat belt 50 years ago.

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Buckle Up Your Seatbelt and Behave

Do we take more risks when we feel safe? Fifty years after we began using the three-point seatbelt, there's a new answer

  • By William Ecenbarger
  • Smithsonian magazine, April 2009

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    In the middle of the last century, Volvo began seeking improvements to seat belts to protect drivers and passengers in its vehicles. When the Swedish automaker tried a single strap over the belly, the result was abdominal injuries in high-speed crashes. The engineers also experimented with a diagonal chest restraint. It decapitated crash-test dummies.

    Volvo then turned to a 38-year-old mechanical engineer named Nils Bohlin, who had developed pilot ejector seats for the Saab aircraft company. Bohlin knew it would not be easy to transfer aerospace technology to the automobile. "The pilots I worked with in the aerospace industry were willing to put on almost anything to keep them safe in case of a crash," he told an interviewer shortly before he died, in 2002, "but regular people in cars don't want to be uncomfortable even for a minute."

    After a year's research and experimentation, Bohlin had a breakthrough: one strap across the chest, another across the hips, each anchored at the same point. It was so simple that a driver or passenger could buckle up with one hand. Volvo introduced the result—possibly the most effective safety device ever invented—50 years ago; other automakers followed suit. No one can tally exactly how many lives Bohlin's three-point seat belt has spared, but the consensus among safety experts is at least a million. Millions more have been spared life-altering injuries.

    But before we break out the champagne substitute to honor the three-point seat belt's demi-centennial, we might also consider the possibility that some drivers have caused accidents precisely because they were wearing seat belts.

    This counterintuitive idea was introduced in academic circles several years ago and is broadly accepted today. The concept is that humans have an inborn tolerance for risk—meaning that as safety features are added to vehicles and roads, drivers feel less vulnerable and tend to take more chances. The feeling of greater security tempts us to be more reckless. Behavioral scientists call it "risk compensation."

    The principle was observed long before it was named. Soon after the first gasoline-powered horseless carriages appeared on English roadways, the secretary of the national Motor Union of Great Britain and Ireland suggested that all those who owned property along the kingdom's roadways trim their hedges to make it easier for drivers to see. In response, a retired army colonel named Willoughby Verner fired off a letter to the editor of the Times of London, which printed it on July 13, 1908.

    "Before any of your readers may be induced to cut their hedges as suggested by the secretary of the Motor Union they may like to know my experience of having done so," Verner wrote. "Four years ago I cut down the hedges and shrubs to a height of 4ft for 30 yards back from the dangerous crossing in this hamlet. The results were twofold: the following summer my garden was smothered with dust caused by fast-driven cars, and the average pace of the passing cars was considerably increased. This was bad enough, but when the culprits secured by the police pleaded that ‘it was perfectly safe to go fast' because ‘they could see well at the corner,' I realised that I had made a mistake." He added that he had since let his hedges and shrubs grow back.

    Despite the colonel's prescience, risk compensation went largely unstudied until 1975, when Sam Peltzman, a University of Chicago economist, published an analysis of federal auto-safety standards imposed in the late 1960s. Peltzman concluded that while the standards had saved the lives of some vehicle occupants, they had also led to the deaths of pedestrians, cyclists and other non-occupants. John Adams of University College London studied the impact of seat belts and reached a similar conclusion, which he published in 1981: there was no overall decrease in highway fatalities.

    There has been a lively debate over risk compensation ever since, but today the issue is not whether it exists, but the degree to which it does. The phenomenon has been observed well beyond the highway—in the workplace, on the playing field, at home, in the air. Researchers have found that improved parachute rip cords did not reduce the number of sky-diving accidents; overconfident sky divers hit the silk too late. The number of flooding deaths in the United States has hardly changed in 100 years despite the construction of stronger levees in flood plains; people moved onto the flood plains, in part because of subsidized flood insurance and federal disaster relief. Studies suggest that workers who wear back-support belts try to lift heavier loads and that children who wear protective sports equipment engage in rougher play. Forest rangers say wilderness hikers take greater risks if they know that a trained rescue squad is on call. Public health officials cite evidence that enhanced HIV treatment can lead to riskier sexual behavior.

    All of capitalism runs on risk, of course, and it may be in this arena that risk compensation has manifested itself most calamitously of late. William D. Cohan, author of House of Cards, a book about the fall of Bear Stearns, speaks for many when he observes that "Wall Street bankers took the risks they did because they got paid millions to do so and because they knew there would be few negative consequences for them personally if things failed to work out. In other words, the benefit of their risk-taking was all theirs and the consequences of their risk-taking would fall on the bank's shareholders." (Meanwhile investors, as James Sur­owiecki noted in a recent New Yorker column, tend to underestimate their chances of losing their shirts.) Late last year, 200 economists—including Sam Peltzman, who is now professor emeritus at Chicago—petitioned Congress not to pass its $700 billion plan to rescue the nation's overextended banking system in order to preserve some balance between risk, reward and responsibility. Around the same time, columnist George Will pushed the leaders of the Big Three automakers into the same risk pool.

    In the middle of the last century, Volvo began seeking improvements to seat belts to protect drivers and passengers in its vehicles. When the Swedish automaker tried a single strap over the belly, the result was abdominal injuries in high-speed crashes. The engineers also experimented with a diagonal chest restraint. It decapitated crash-test dummies.

    Volvo then turned to a 38-year-old mechanical engineer named Nils Bohlin, who had developed pilot ejector seats for the Saab aircraft company. Bohlin knew it would not be easy to transfer aerospace technology to the automobile. "The pilots I worked with in the aerospace industry were willing to put on almost anything to keep them safe in case of a crash," he told an interviewer shortly before he died, in 2002, "but regular people in cars don't want to be uncomfortable even for a minute."

    After a year's research and experimentation, Bohlin had a breakthrough: one strap across the chest, another across the hips, each anchored at the same point. It was so simple that a driver or passenger could buckle up with one hand. Volvo introduced the result—possibly the most effective safety device ever invented—50 years ago; other automakers followed suit. No one can tally exactly how many lives Bohlin's three-point seat belt has spared, but the consensus among safety experts is at least a million. Millions more have been spared life-altering injuries.

    But before we break out the champagne substitute to honor the three-point seat belt's demi-centennial, we might also consider the possibility that some drivers have caused accidents precisely because they were wearing seat belts.

    This counterintuitive idea was introduced in academic circles several years ago and is broadly accepted today. The concept is that humans have an inborn tolerance for risk—meaning that as safety features are added to vehicles and roads, drivers feel less vulnerable and tend to take more chances. The feeling of greater security tempts us to be more reckless. Behavioral scientists call it "risk compensation."

    The principle was observed long before it was named. Soon after the first gasoline-powered horseless carriages appeared on English roadways, the secretary of the national Motor Union of Great Britain and Ireland suggested that all those who owned property along the kingdom's roadways trim their hedges to make it easier for drivers to see. In response, a retired army colonel named Willoughby Verner fired off a letter to the editor of the Times of London, which printed it on July 13, 1908.

    "Before any of your readers may be induced to cut their hedges as suggested by the secretary of the Motor Union they may like to know my experience of having done so," Verner wrote. "Four years ago I cut down the hedges and shrubs to a height of 4ft for 30 yards back from the dangerous crossing in this hamlet. The results were twofold: the following summer my garden was smothered with dust caused by fast-driven cars, and the average pace of the passing cars was considerably increased. This was bad enough, but when the culprits secured by the police pleaded that ‘it was perfectly safe to go fast' because ‘they could see well at the corner,' I realised that I had made a mistake." He added that he had since let his hedges and shrubs grow back.

    Despite the colonel's prescience, risk compensation went largely unstudied until 1975, when Sam Peltzman, a University of Chicago economist, published an analysis of federal auto-safety standards imposed in the late 1960s. Peltzman concluded that while the standards had saved the lives of some vehicle occupants, they had also led to the deaths of pedestrians, cyclists and other non-occupants. John Adams of University College London studied the impact of seat belts and reached a similar conclusion, which he published in 1981: there was no overall decrease in highway fatalities.

    There has been a lively debate over risk compensation ever since, but today the issue is not whether it exists, but the degree to which it does. The phenomenon has been observed well beyond the highway—in the workplace, on the playing field, at home, in the air. Researchers have found that improved parachute rip cords did not reduce the number of sky-diving accidents; overconfident sky divers hit the silk too late. The number of flooding deaths in the United States has hardly changed in 100 years despite the construction of stronger levees in flood plains; people moved onto the flood plains, in part because of subsidized flood insurance and federal disaster relief. Studies suggest that workers who wear back-support belts try to lift heavier loads and that children who wear protective sports equipment engage in rougher play. Forest rangers say wilderness hikers take greater risks if they know that a trained rescue squad is on call. Public health officials cite evidence that enhanced HIV treatment can lead to riskier sexual behavior.

    All of capitalism runs on risk, of course, and it may be in this arena that risk compensation has manifested itself most calamitously of late. William D. Cohan, author of House of Cards, a book about the fall of Bear Stearns, speaks for many when he observes that "Wall Street bankers took the risks they did because they got paid millions to do so and because they knew there would be few negative consequences for them personally if things failed to work out. In other words, the benefit of their risk-taking was all theirs and the consequences of their risk-taking would fall on the bank's shareholders." (Meanwhile investors, as James Sur­owiecki noted in a recent New Yorker column, tend to underestimate their chances of losing their shirts.) Late last year, 200 economists—including Sam Peltzman, who is now professor emeritus at Chicago—petitioned Congress not to pass its $700 billion plan to rescue the nation's overextended banking system in order to preserve some balance between risk, reward and responsibility. Around the same time, columnist George Will pushed the leaders of the Big Three automakers into the same risk pool.

    "Suppose that in 1979 the government had not engineered the first bailout of Chrysler," Will wrote. "Might there have been a more sober approach to risk throughout corporate America?"

    Now researchers are positing a risk compensation corollary: humans don't merely tolerate risk, they seek it; each of us has an innate tolerance level of risk, and in any given situation we will act to reduce—or increase—the perceived risk, depending on that level.

    The author and principal proponent of this idea is Gerald J.S. Wilde, professor emeritus of psychology at Queen's University in Kingston, Ontario. In naming his theory "risk homeostasis," Wilde borrowed the word used for the way we humans, without knowing it, regulate our body temperature and other functions. "People alter their behavior in response to the implementation of health and safety measures," Wilde argued in his 1994 book, Target Risk. "But the riskiness of the way they behave will not change, unless those measures are capable of motivating people to alter the amount of risk they are willing to incur." Or, to make people behave more safely, you have to reset their risk thermostats.

    That, he says, can be done by rewarding safe behavior. He notes that when California promised free driver's-license renewals for crash-free drivers, accidents went down. When Norway offered insurance refunds to crash-free younger drivers, they had fewer accidents. So did German truck drivers after their employers offered them bonuses for accident-free driving. Studies indicate that people are more likely to stop smoking if doing so will result in lower health and life insurance premiums.

    Wilde's idea remains hotly disputed, not least by members of the auto-safety establishment. "Wilde would have us believe that if you acquire a brand-new car with air bags, you will decide to drive your new car with more reckless abandon than your old one," says Anne McCartt, a senior vice president for the Insurance Institute for Highway Safety, a nonprofit organization funded by auto insurers. "You will be unconcerned that your more reckless driving behavior will increase the chances of crashing and damaging your new car because returning to your previous level of injury risk is what you really crave! Only abstract theoreticians could believe people actually behave this way."

    Still, even the institute acknowledges that drivers do compensate for risk to some degree, particularly when a safety feature is immediately obvious to the driver, as with anti-lock brakes. But seat belts? No way, says McCartt.

    "We've done a number of studies and did not find any evidence" that drivers change their behavior while wearing them.

    Questions over risk compensation will remain unresolved because behavioral change is multidimensional and difficult to measure. But it is clear that to risk is human. One reason Homo sapiens rules the earth is that we are one of history's most daring animals. So how, then, should we mark the 50th anniversary of the seat belt?

    By buckling up, of course. And by keeping in mind some advice offered by Tom Vanderbilt in Traffic: Why We Drive the Way We Do (and What It Says About Us): "When a situation feels dangerous to you, it's probably more safe than you know; when a situation feels safe, that is precisely when you should feel on guard." Those are words even the parachutists, wilderness hikers and investors among us can live by.

    William Ecenbarger is a former contributing editor for Reader's Digest.


    1 2



    Additional Sources

    Target Risk 2: A New Psychology of Safety and Health by Gerald J.S. Wilde, PDE publications, 2001

     
    Comments

    "Risk Compensation" can be viewed as "moral hazard" -- a term that is getting used a lot these days by economists and others. Moral hazard is an example of the "Principal Agent problem," whereby the agent's interest's diverge from the principle's. This article does a fabulous job of integrating the incentives that cause an increase in individual risk-taking; whether it be driving fast at intersections or lending to borrowers who may not be able to repay. This type of analysis is similar to that of Ron Coase (and Harold Demsetz, Arman Alcian, etc....)

    Posted by Bruce Brown on March 27,2009 | 10:12AM

    I ride a motorcycle to and from work. I wore seat belts before they were required and a helmet before they were required, along with other protective gear. I feel much better when I arrive home after riding through LA rush hour traffic than when I drive my car. I've known intuitively that I take more risks when I'm wearing protective gear. I try to compensate but I'm sure if I didn't have the gear, I'd drive/ride much more carefully.

    Posted by Chris Baker on April 9,2009 | 12:22PM

    There is of course some truth to the adage of taking more risks when having more protection. One could also quantify such examples as drivers of larger SUVS and trucks who are more aggressive since they assume a shield of protection vs. compact car drivers who feel more vulnerable. A proper response would be for a driver to use the capabilities of his/her vehicle to its best degree, e.g., motorcycles as eminently maneuverable, small cars as intermediate, and large cars only as cocoons.

    I write extensively about the history of motor sport and there are many lessons there. In the 1950s the sport was horrifically dangerous. Some 1/3 of Grand Prix drivers could be expected to die within 3-4 years. Competitors treated each other on the circuit with utmost respect, knowing that missed signals between them could lead to death. In the intervening years a massive effort at improving race car and circuit safety as well as incident response has led to a situation where there are far fewer serious injuries in motor racing than in high school football. Consequently, the racing has become much rougher. Drivers are no longer shy about bumping competitors out of the way, knowing that injury is not likely. Or to put it crassly as seen on a t-shirt, "I remember when sex was safe and racing was dangerous."

    Posted by Janos Wimpffen on April 11,2009 | 10:54AM

    Of course this is true.
    When I bought a Fiat 210 sports car after driving a Ford sedan for a number of years. The change in my driving behavior was obvious to anyone who rode with me. The feeling of power, and complete control was enhanced by the smaller size, more sensitive handling, greater acceleration and shorter stopping distances.

    Posted by Thomas on April 13,2009 | 07:02AM

    Improved safety gear promotes more-risky behavior? Well, yeah. THAT'S THE WHOLE IDEA.

    Reward requires risk. We do not drive at high speed because we prefer to exist in risky situations; we drive at high speed because we arrive at our destination sooner.

    This article is the height of neo-Puritan lunacy; its basic assumption is that cars are extremely dangerous, and that the source of this danger is speed, and that anything which permits higher speed is inherently dangerous. Furthermore, it conflates "risk" with "danger"--a common failing of modern thinkers.

    Posted by DensityDuck on April 13,2009 | 04:18PM

    As soon as I read this article I thought of this (from Wiki)

    (about the song "Red Barchetta" by Rush)

    The song was inspired by the futuristic short story "A Nice Morning Drive," written by Richard Foster and published in the November, 1973 issue of Road and Track magazine. The story describes a similar future in which increasingly-stringent safety regulations have forced cars to evolve into massive "Modern Safety Vehicles" (MSVs), capable of withstanding a 50-mile-per-hour impact without injury to the driver. Consequently, drivers of MSVs have become less safety-conscious and more aggressive, and "bouncing" (intentionally ramming) the older, smaller cars is a common sport among some.

    Posted by Mike Motz on April 13,2009 | 10:55PM

    Neo-Puritan lunacy? I beg to differ. This article does not hypothesize that the source of a car's danger is speed. It DOES hypothesize that the source of a car's danger is the delusion of control of the driver (or, as my parents used to say, "the nut that holds the wheel.") I think DensityDuck just made the author's point for him. And I am personally acquainted with more than one driver who drives fast because he likes to drive fast, not because he's in a hurry to get someplace.

    Posted by J. H. Horsman on April 14,2009 | 11:46AM

    I suppose the three-point seatbelt is supposed to save me during the accident I have because I passed out because the wretched thing insists on lying tightly against my carotid. No, it won't stay loose until snapped tight by impact! I've been wondering for years if children are being deprived of knowledge of consequences. They're so padded now, I'm surprised every time I see a box of Band-Aids for sale.

    Posted by Cece on April 14,2009 | 12:48PM

    I cannot help but notice that virtually all of the initiatives cited in this article that promote (or mandate) the externalization of risk (as Bruce Schneier would call it) and the resulting damage from incentive dislocations and unintended consequences, are the direct result of government intervention in private affairs. Is there a possible corollary here to the effects of government-induced misallocation of resources as identified by disciples of the Austrian school of economics? One more reason to abolish the State. -AleG

    Posted by Alexander Goristal on April 14,2009 | 04:22PM

    So, you want to learn to drive more carefully?
    Ride on an ambulance or Fire Deparment rescue truck, especailly near an interstate for a while.
    It won't take long, trust me.

    Posted by A Brown on April 16,2009 | 01:46PM

    "Counter-intuivity" is no valid argument against a view when it is supported by scientifiic evidence. Ever since Galileo we know that the earth revolves around the sun, not the other way around. But the erroneous illusion/intuition is so strong, that many centuries later, we still speak of sunset and sunrise, while they actually are "earthset" and "earthrise." Anybody interested in risk homeostasis theory, and the evidence that would appear to support it, is referred to Wilde, GJS, "Target Risk 2" published by PDE Publications, Toronto, in 2001

    Posted by Gerald JS Wilde on June 3,2009 | 10:57PM

    William Ecenbarger credits Saab engineer, Nils Bohlin, with the development of the 3-point auto safety belt "50 years ago." In 1954 I started by medical internship at Denver General Hospital, Denver, Colorado. One of my fellow interns told me that there was a place in Denver where I could have safety belts installed in my car. I visited Rose Mfg. Co. where I met owner Clarence Rose who made industrial safety harnesses for window washers, etc. He had observed that in intersection accidents the struck car often spun around, doors flying open and occupants ejected onto the pavement to be struck by other cars. He reasoned that if passengers could be belted and kept within the car injuries or deaths could be avoided. He actually did his own testing by pulling old cars up to the ceiling of his warehouse and dropping them front-end first on the cement floor below.

    He installed 3-point belts in my '53 Ford in 1954 which I used until belts became available many years later. The belts were bolted to the floor behind the front seat and the shoulder strap was bolted to the roof of the car above the door post. I don't know when Clarence Rose began installing these belts, but using the 1954 date that makes the 3-point belt system at least 55 years old. Could similar systems have been developed coincidentally by two different safety engineers in two different countries at so nearly the same time?

    Richard Brown, M.D.
    Mesa, Arizona

    Posted by Richard Brown, M.D. on June 17,2009 | 01:38PM

    aawww.
    this is the reason why you should never forget the rule of a seat belt

    Posted by sophie on June 28,2009 | 09:58PM

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