We have brains that, in line with the Anchoring Rule, use the first available number as the basis for making an estimate about something that has absolutely nothing to do with the number. This is not helpful at a time when we are pelted with numbers like raindrops in a monsoon.
We have brains that defy logic by using the Rule of Typical Things to conclude that elaborate predictions of the future are more likely to come true than simple predictions. At a time when we are constantly warned about frightening future developments, this, too, is not helpful.
Most important, we have brains that use the Example Rule to conclude that being able to easily recall examples of something happening proves that it is likely to happen again. For ancient hunters stalking wildebeest on the savanna, that wasn’t a bad rule. In an era when tourists can e-mail video of a tsunami to the entire planet in less time than it takes the wreckage to dry, it has the potential to drive us mad. Should we fear exotic viruses? Terrorists? Pedophiles stalking kids on the Internet? Any of the other items on the long and growing list of worries that consume us? The population of humans on the planet is approaching seven billion. On any given day, by sheer force of numbers, there’s a good chance that some or all of these risks will result in people being hurt or killed. Occasionally, there will be particularly horrible incidents in which many people will die. And thanks to the torrent of instantaneous communications, we will all know about it. So, should we fear these things? Inevitably, Gut will attempt to answer that question using the Example Rule. The answer will be clear: Yes. Be afraid.
One of the most consistent findings of risk-perception research is that we overestimate the likelihood of being killed by the things that make the evening news and underestimate those that don’t. What makes the evening news? The rare, vivid, and catastrophic killers. Murder, terrorism, fire, and flood. What doesn’t make the news is the routine cause of death that kills one person at a time and doesn’t lend itself to strong emotions and pictures. Diabetes, asthma, heart disease. In American surveys conducted in the late 1970s by Paul Slovic and Sarah Lichtenstein, the gaps between perception and reality were often stunning. Most people said accidents and disease kill about equally—although disease actually inflicts about seventeen times more deaths than accidents. People also estimated that car crashes kill 350 times more people than diabetes. In fact, crashes kill only 1.5 times as many. How could the results be otherwise? We see flaming wrecks every day on the news but only family and friends will hear of a life lost to diabetes.
Considerable research has tied skewed risk perception to skewed coverage in the news, but information and images pour out of more sources than newspapers, magazines, and suppertime broadcasts. There are also movies and television dramas. These are explicitly designed to be emotional, vivid, and memorable. And risk is a vital component of countless dramas—primetime television would be dead air if cop shows and medical dramas disappeared. Based on what psychologists have learned about the Example Rule, they should have just as powerful an effect on our judgments about risk as the news does. They may even have greater impact. After all, we see movies and TV dramas as nothing more than entertainment, so we approach them with lowered critical faculties: Gut watches while Head sleeps.
Unfortunately, almost no research has examined how fiction affects risk perception. One recent study, however, found just what psychologists would expect. Anthony Leiserowitz of Decision Research (a private research institute founded by Paul Slovic, Sarah Lichtenstein, and Baruch Fischhoff) conducted cross-country surveys in the United States before and after the release of The Day After Tomorrow, a disaster film depicting a series of sudden, spectacular catastrophes unleashed by global warming. The science in The Day After Tomorrow is dubious, to say the least. Not even the most frightening warnings about the effects of global warming come close to what the movie depicts. But that made no difference to the influence of the film. Across the board, more people who saw the film said they were concerned about global warming, and when they were asked how likely it was that the United States would experience various disasters similar to those depicted in the movie—flooded cities, food shortages, Gulf Stream shutdown, a new Ice Age, etc.—people who had seen the movie consistently rated these events more likely than those who didn’t. The effects remained even after the numbers were adjusted to account for the political leanings of respondents.
Of course, Head can always step in, look at the evidence, and overrule. As we have seen, it routinely does not. But even if it did, it could only modify or overrule Gut’s judgment, not erase it. Head can’t wipe out intuition. It can’t change how we feel.
Most sociologists trace the beginning of the Western countries’ obsession with risk and safety to the 1970s. That was also when the near-exponential growth in media began and the information floodwaters started to rise. Of course, the fact that these two profound shifts started together does not prove they are connected, but it certainly is grounds for suspicion and further investigation.
4
The Emotional Brain
It is remarkable how many horrible ways we could die. Try making a list. Start with the standards like household accidents and killer diseases. After that, move into more exotic fare. “Hit by bus,” naturally. “Train derailment, ” perhaps, and “stray bullet fired by drunken revelers.” For those with a streak of black humor, this is where the exercise becomes enjoyable. We may strike a tree while skiing, choke on a bee, or fall into a manhole. Falling airplane parts can kill. So can banana peels. Lists will vary depending on the author’s imagination and tolerance for bad taste, but I’m quite sure that near the end of every list will be this entry: “Crushed by asteroid.”
Everyone knows that deadly rocks can fall from the sky, but outside space camps and science-fiction conventions, the threat of death-by-asteroid is used only as a rhetorical device for dismissing some worry as real but too tiny to worry about. I may have used it myself once or twice. I probably won’t again, though, because in late 2004 I attended a conference that brought together some of the world’s leading astronomers and geoscientists to discuss asteroid impacts.
The venue was Tenerife, one of Spain’s Canary Islands that lie off the Atlantic coast of North Africa. Intentionally or not, it was an ideal setting. The conference was not simply about rocks in space, after all. It was about understanding a very unlikely, potentially catastrophic risk. And the Canary Islands are home to two other very unlikely, potentially catastrophic risks.
First, there are the active volcanoes. All the islands were created by volcanic activity, and Tenerife is dominated by a colossus called Teide, the third-largest volcano in the world. Teide is still quite active, having erupted three times in the last 300 years.
And there is the rift on La Palma mentioned in the last chapter. One team of scientists believes it will drop a big chunk of the island into the Atlantic and several hours later people on the east coast of North and South America will become extras in the greatest disaster movie of all time. Other scientists dispute this, saying a much smaller chunk of La Palma is set to go, that it will crumble as it drops, and that the resulting waves won’t even qualify as good home video. They do agree that a landslide is possible, however, and that it is likely to happen soon in geological terms—which means it could be 10,000 years from now, or tomorrow morning.