I want you to look at two photographs. One is of a car crash. The other is of a great white shark. Which of these two risks are you more frightened of? I think most of us would instinctively say shark, right? But which of these two risks are a more common cause of death? Clearly the automobile and traffic accidents are a much, much larger cause of death than attacks by great white sharks. So this brings us to a question: Why are we more frightened of some forms of death and some kinds of risk than of others? Now in the 1980s, a group of psychologists, behavioral scientists, devised something known as the psychometric paradigm and two of the scholars behind it were Paul Slovic and Baruch Fischhoff, and they asked themselves the question: How do people perceive risk? And why is there a difference between the way experts perceive risk and members of the public perceive risk? They came to the conclusion that experts tend to judge risk by annual fatalities. So a bigger risk is something that kills more people in the course of a year or any period of time. The public, that includes all of us, you and me, tend to judge risks not by the numbers, but by the characteristics of the risk. Let me give you some examples. Risks that provoke a feeling of dread such as shark attacks tend to be perceived by people as high risk. Risks that are voluntary, for example driving a car, tend to be seen as lower risk. Risks that are known, running across a road and the red man is blinking at you, tend to be seen as lower risk than those that are unknown, an infectious disease epidemic, caused by an unknown virus, for example. To understand this we can develop a grid, a grid with four poles. One set of poles are unknown and known. Another set of poles as you can see from the slide is dread and not dread. What do we mean by known, unknown, dread, not dread? What are some of the characteristics of this? Things that we dread are risks that are uncontrollable, a nuclear meltdown, for example. Catastrophic, high risk to future generations, threat of radiation for example, which can cause genetic damage. Involuntary risks, "I'm happy to take a risk I take myself, but if you make me take a risk, I'm not going to be that happy about it". Risks that are not easy to reduce and risks that have no conceivable benefit. Now these are some of the factors that cause, that have been clumped together as dread. At the other end of the axis, the other pole if you will, are risks that we don't dread that much and these are risks that we think are controllable: running across the road, low risk to future generations. They're easy to reduce, risks that are voluntary and this is typically, I mean smokers. Think about smoking for example. Smokers themselves really don't see what they're, many of them don't regard their actions as particularly risky, why? Because they say, "Hey, this is voluntary. I'm not risking future generations". And all smokers believe that, "One day I can always stop." Then risks that we don't dread also give us some form of benefit, whether it is the feeling of satisfaction that we get from eating food that we shouldn't be eating or perhaps the satisfaction that a smoker gets from sneaking around the corner and having a couple of quick drags. All of these are seen as benefits. Now we can argue whether these actually benefits or not, but to the person performing or indulging in this behavior, they do bring clear benefits and therefore they're not really dreaded. The other axis had two poles. One is unknown and one is known. So what are some of the characteristics? Something that is unknown, a risk that is unknown is something that is not observable. Once more if we think back, part of the dread that we feel from nuclear accidents is this, we can't see it. We can't see radiation, can we? It is unknown to those who are exposed. You don't know whether you're being exposed to radiation unless you have a Geiger counter and we're also pretty unhappy at undertaking risks that are unknown to science and this is one more reason why diseases caused by new viruses do evoke a certain dread. The other end is a so-called known pole and these are risks that are observable, I can see the risk I'm taking. Riding a motorcycle at high speeds even without a helmet on, it is a risk but if you, "Hey, I've done this before and I can see. There's something I can see. I can see the traffic around me. People can see me, I'll take the risk." Risks that are old, that is behaviors that you have been doing for a long time, risks for which the effect in a sense is immediate. I know if I do something or something goes wrong, the effect is immediate. I don't have to wait ten years for something to happen, so I feel like I can control it because it's immediate. And risks that are known to science, somehow we feel are something, are things that we can manage better than risks that we don't know. So these are some of the factors that cluster together around the known pole. Okay, let's use this grid that we have to look at the case of the attack by the great white shark. Now where would we place perceptions of shark attacks on this grid? Now on the one hand, being bitten by a shark or attacked by a shark definitely evokes dread. I don't think there's any two questions about that, so clearly it will be on the dread axis. On the other hand, so it's not completely unknown. We know that there is a risk of being attacked by sharks. So, in a sense, it is known. It's an old risk. It's a known risk. So this is something that would be on the dread axis, that is on the right-hand side, but on the lower right-hand side. So here's a question that I'm going to leave you with now: Where would a newly emerging infectious disease fall on this grid?
