"If it hasn't happened yet, it will never happen"
This is what happens when you do not wear your seatbelt for five years in a row. You assume that you are safe because nothing has happened. You believe that there is a pattern. You do not conclude that your luck may be running out.
"I saw it on the news"
If I were to ask you, "What is the likelihood that you will be a victim of a terrorist attack", you might consider what the recent news stories have been-especially if you live in New York City. One of my patients concluded two months after the September 11th terrorist attacks in New York that the chances that she would be killed by a terrorist were 100%. How does someone come up with this estimate?
Like many other people who are frightened by terrorism she will rely on what she sees on the daily news, the presence of armed soldiers in Manhattan, pictures of terrorist attacks on television, and the fact that she lives in a city where there was a terrorist attack. One woman who feared a terrorist attack increased her alcohol abuse and increased smoking cigarettes. She was estimating that the risk of dying from terrorism far outweighed the risk of dying from the effects of lung cancer or alcoholism.
But what are the real risks?
Overestimating Risk
Let's imagine that you have just seen a news story on television of a shark attack in Florida and you are now planning on swimming at a beach in New Jersey. How afraid of a shark attack are you? You might be very frightened and decide to stay on shore.
How risky are these behaviors? In a fascinating compilation edited by David Ropeik and George Gray of the Harvard Center for Risk Analysis, scientists and experts from different disciplines calculated the real-world risks for a variety of behaviors or hazards.16 These scientists calculated risk by considering the following: Hazard---the substance, agent, or behavior (e.g., smoking); Range of exposures-how we are exposed and over what period of time; Range of consequences---how much harm is done and to how many people? All of the risk estimates are calculated for the United States.
Consider the one-year odds of the risk of being killed by a shark---280 million to one. Now consider the life-time risk of dying from the effects of smoking---about one in two---half of the people who are currently smoking who continue to smoke will die from smoking. Or consider the relative odds of being killed in a car accident vs. flying in a commercial airplane. However, many more people have a fear of flying than a fear of driving-indeed, many people with a fear of flying will drive 1000 miles to avoid flying.
Factors Affecting Overestimation of Risk
Psychologists have been interested in the degree to which people over-estimate certain risks-and underestimate others. I have listed below several of the dimensions that psychologists have identified that are associated with overestimating risks.17
1. It's uncontrollable
2. You don't like the activity
3. It's involuntary
What do these dimensions of risk represent? We often believe that hazards that are uncontrollable---for example, sharks, radiation, and terrorism---are more risky. So, if we believe that we have control over an activity-like we might convince ourselves that we are in control of our eating, drinking, smoking and sexual behavior-then we will underestimate these risks. We also believe that if we like an activity, then it is less risky. Thus, we may believe that smoking and drinking-behaviors that we may enjoy-are less risky. Finally, we also tend to believe that behaviors that are voluntary-and also within our control---are less risky.
How can we apply these dimensions to evaluating how we underestimate risk? First, there certainly are horrible consequences of smoking or dying from cirrhosis from alcoholism. But we should keep in mind that in assessing the risk of the next behavior-the risk of smoking a cigarette in the next five minutes while having a drink-will not lead to a horrible consequence. Second, our intuition is that the next cigarette or drink will not kill us-and that overeating at the buffet will not make us obese. Again, we tend to be near-sighted---focusing on this next behavior and its consequences. Third, how "newsworthy" the behavior is and how much are people talking about it affects risk assessment. It's doubtful that we are hearing about how dangerous our smoking and drinking and overeating are--- these are not newsworthy stories. Ironically, the reason that these are not newsworthy stories is that they are so common. Thus, we are not reading on the front page of the risk of our own behavior because these problems are so common throughout the country that they are no longer newsworthy. This is why it seems so ludicrous to almost everyone that an obese person would sue McDonald's because he ate so many cheeseburgers and fries that he got fat. "Everyone knows that eating high-fat foods will make you fat". It is not newsworthy-because everyone knows it. And, ironically, because everyone knows it, he was not thinking about the risks he was taking.
How uncontrollable the hazard might be also makes us reduce our estimate of risk. We do "control" whether we drive our car-but we do not control the airplane. Thus, we consider the plane more dangerous than the car. We control whether we have a cigarette, a drink or a cheeseburger-so we may think it is less risky. We may also be kidding ourselves in thinking that we will be able to choose or control stopping these somewhat addictive behaviors. Also, we underestimate risk because we like these behaviors. "How bad can it be if it feels so good?" Thus, we enjoy smoking, drinking, overeating, and spending money---so it feels less risky. And, finally, we have voluntarily engaged in this behavior---we have freely chosen to smoke, drink or spend---so we want to justify our own choices by convincing ourselves that our behavior is not risky.
Consistently Underestimating Risk
Certainly none of us wants to be obese, die from lung cancer, or get killed in a head-on-collision. No one wants to have an undetected cancer continue to grow or to slowly go bankrupt. The reason for many of these preventable risks cannot be due to lack of information. Is there anyone today who doubts that smoking causes cancer? Or that eating high-calorie foods without exercise will result in weight-gain? Or that early detection of cancer can save your life? Is it out of ignorance that people incur debt at 21% --and never get out of debt? Almost everyone knows that herpes is epidemic and that not using birth control can make you a parent.
So, why do people seem to ignore the dangers that might result from their own choices? I will argue here that-just as distortions in thinking lead us to overestimate risks for some things--there are distortions in thinking that lead us to ignore risks that can kill us. Let's look at some of the ways in which we keep our blinders on.
Familiarity Breeds Risk
We often think that the things that we are doing on a regular basis have become safer. For example, if you smoke, you think that "smoking hasn't killed me yet", or if you are overweight, you think, "I haven't had a heart attack yet". The same thing is true for daily bad habits---if you drink too much, overeat or spend too much-you will think that the fact that nothing terrible has happened (yet) is evidence that you are safe. Familiarity with risky behavior lulls you into thinking that things are not so bad. Some people say, "I never use a seatbelt" or "I never wear a prophylactic" and then conclude that the absence of a bad outcome is evidence that they are somehow immune.
Russian Roulette-Are You Feeling Lucky Today?
But imagine if we compared this to playing Russian roulette. I tell you that there is one bullet in this gun-but I don't tell you how many chambers there are in the barrel. You take the gun, point it at your head, spin the barrel and pull the trigger. Nothing happens. Let's imagine that I give you a very pleasant reward---for you, a shot of scotch. You then decide, "Hmm. I can get another drink by playing this game." Time after time you spin the barrel and pull the trigger. You are feeling more lucky, more sure of yourself. You begin to think that you have real skill at this game and that you are immune from any bad consequences. You think, "Maybe there's no bullet in the gun".
