Sharks and Dread Risk.

Imagine you’re sitting on the beach staring out at the sea. You’re thinking, ‘Where are the sharks? If I go for a swim, will they eat me?’

If you’re in Sydney, you’re probably thinking of this acutely following the recent fatal attack (the first in nearly 60 years.) You’re not thinking about the risk of skin cancer nearly as passionately – though the likelihood of that striking you is far higher than a shark attack. Nor the chance of you drowning – which is also much higher than a shark attack. You’re just imagining the worst thing you can that’s associated with the ocean, which is a shark chomping you in half.

This is dread risk. Certain fears (and types of death) haunt our nightmares more than others. Risk expert Gerd Gigerenzer defines it as a ‘low probability, high damage event.’ Sometimes, the likelihood of a certain event happening – dying from a shark attack, crashing to earth in a plane crash, being taken down by a random gunman or terrorist – is extremely low but we still worry about it.

However, most of us don’t lie awake worrying about catching skin cancer or cardiovascular disease.


Part of it is control. We know we can’t control a shark attack (though, as our chapter on animals shows, there are some things you can do – see the book) so we exaggerate the risk as a type of protective mechanism. Fight or flight instincts come to play and tend to win over a rational assessment. We are now more ready to fight the shark. Skin melanoma doesn't require the same heightened response. Control is also why texting and driving seems less risky when you do it, but horrifying when you look across and see the driver next to you on the phone. You know what you’re doing, but you’ve got no assurance they do, and you can’t control them if they plough into you.

Dread Risk is also linked to what’s sometimes called the availability heuristic. If you’ve read about a shark attack recently in the media, or a bombing on a train, or an outbreak of legionnaire’s diseases in nursing homes, it’s much more available to your conscious and therefore your brain gives it more weight. [1] The fact that every year a certain number of people in nursing homes die from legionnaire’s and that this year is no different, doesn’t matter. You read about it yesterday so it’s fresh in your mind. It is suddenly very, very concerning and imminent for you. When you combine the availability heuristic with something you have no control over (and, not surprisingly, something that concerns you), you have the makings of a serious dread risk.

“So what?” you may be thinking. “Let me worry about what I want. No harm done and, in fact, I’ll be better prepared.”

Well, maybe.

But, Dread Risk can actually cause you to engage in more risky behaviours. Immediately after the attacks on September 11, 2001, airflights across America were grounded as authorities desperately tried to work out what was happening. It took many weeks to get flights operating again while improved security measures were installed at many airports. But even once the planes were operating as normal, many people chose to drive, both short distances and long, rather than fly. In the United States, driving is many times more dangerous than flying. It is far, far more risky.

Risk expert Gerd Gigerenzer, who wrote a famous paper on dread risk and 9/11, estimated this change in behaviour led to an additional 1000 deaths in just the 3 months immediately after the attacks.[2] The elevated level of fear associated with flying brought about a classic example of dread risk thinking.

We have to watch out for dread risk thinking because it distracts you from taking action on the things that statistics tell us matter the most about your health.

Certainly, shark attacks happen and you should do everything you can to avoid having to suffer one, but skin cancer happens too. A lot. If every death from skin cancer in Australia received the same amount of new coverage as each shark attack death currently does, our media would be filled with nothing else.

After all, 6 people per day are dying from it.

[1] “Risk Communication - An overlooked tool for improving public health” - David Ropeik, 2008 [2] “Dread Risk, September 11, and Fatal Traffic Accidents” - Gerd Gigerenzer, 2004