Risk and fear are hot topics among sociologists, who have come to a broad consensus that those of us living in modern countries worry more than previous generations. Some say we live in a culture of fear. Terrorists, Internet stalkers, crystal meth, avian flu, genetically modified organisms, contaminated food: New threats seem to sprout like poisonous mushrooms. Climate change, carcinogens, leaky breast implants, the “obesity epidemic,” pesticides, West Nile virus, sars, avian flu, and flesh-eating disease. The list goes on and on. Open the newspaper, watch the evening news. On any given day, there’s a good chance someone – a journalist, activist, consultant, corporate executive, or politician – is warning about an “epidemic” of something or other that threatens you and those you hold dear.

Occasionally, these fears burst into full-bore panics. The pedophile lurking in parks and Internet chat rooms is the latest. In the early 1990s, it was road rage. A decade earlier, it was herpes. Satanic cults, mad cow disease, school shootings, crack cocaine – all these have raced to the top of the public’s list of concerns, only to drop as rapidly as they went up. Some surge back to prominence now and then. Others slip into the category of minor nuisances and are never heard from again. Farewell, herpes.

This is just the stuff of daily news. Authors, activists, consultants, and futurologists are constantly warning us about threats so spectacular and exotic they make scenarios of nuclear Armageddon look quaint. Genetically enhanced bio-weapons, self-replicating nanotechnology turning everything into “grey goo,” weird experiments in physics that create a black hole, sucking in the planet and everyone on it. The millennium bug was a bust but that hasn’t stopped theories of annihilation from piling up so quickly that it’s become almost commonplace to hear claims that humanity will be lucky to survive the next century.

But why are we so afraid? That’s the really tough question. Of course terrorism is a real risk. So are climate change, avian flu, breast cancer, child snatchers, and all the other things that have us wringing our collective hands. But humanity has always faced one risk or another. Why should we worry more than previous generations? We are the healthiest, wealthiest, and longest-lived people in history. And we are increasingly afraid. This is one of the great paradoxes of our time.

So much of what we think and do about risk does not make sense. In a 1990 paper, researchers George Loewenstein and Jane Mather compared people’s levels of concern about nine risks – including aids, crime, and teen suicide – with objective measures of those risks. The results can only be described as scrambled. In some cases, concern rose and fell as the risk rose and fell. In others, there was “wild fluctuation” in levels of concern that had absolutely no connection to the real risk. “There is no generally applicable dynamic relationship between perceived and actual risk,” the researchers politely concluded.

There are countless illustrations of our confused and confusing relationship with risk.

In Europe, where there are more cellphones than people and sales keep climbing, a survey found that more than 50 per cent of Europeans believe the dubious claims that cellphones are a serious threat to health. And then there’s the striking contrast between Europeans’ smoking habits and their aversion to foods containing genetically modified organisms. Surely one of the great riddles to be answered by science is how the same person who doesn’t think twice about lighting a Gauloise will march in the streets demanding a ban on products that have never been proven to have caused so much as a single case of indigestion.

In Europe and elsewhere, people tremble at the sight of a nuclear reactor but shrug at the thought of having an X-ray – even though X-rays expose them to the very same radiation they are terrified might leak from a nuclear plant. Stranger still, they pay thousands of dollars for the opportunity to fly somewhere distant, lie on a beach, and soak up the radiation emitted by the sun – even though the estimated death toll from the Chernobyl meltdown (9,000) is actually quite modest compared to the number of Americans diagnosed with skin cancer each year (more than one million) and the number killed (more than 10,000).

Or compare attitudes about two popular forms of entertainment: watching car races and smoking pot. Over a five-year period, nascar drivers crashed more than 3,000 times. Dale Earnhardt’s death in 2001 was the seventh fatal smash-up in seven years. Governments permit nascar drivers to take these risks, and the public sees nascar as wholesome family entertainment. But if a nascar driver were to relieve post-race stress by smoking marijuana, he would be subject to arrest and imprisonment for possession of a banned substance that governments worldwide have deemed to be so risky not even consenting adults are allowed to consume it – even though it is impossible for someone to consume enough to cause a fatal overdose.

The same logic applies to steroids and other forms of doping: One of the reasons that these substances are banned in sports is the belief that they are so dangerous that not even athletes who know the risks should be allowed to take them. But in many cases, the sports those athletes compete in are far more dangerous than doping. Aerial skiing – to take only one example – requires a competitor to race down a hill, hurtle off a jump, soar through the air, twist, turn, spin, and return to earth safely. The slightest mistake can mean a head-first landing and serious injury, even a broken neck. But aerial skiing isn’t banned. It’s celebrated. In the 2006 Olympics, a Canadian skier who had broken her neck only months before was lionized when she and the metal plate holding her vertebrae together returned to the slopes to once again risk paralysis and death. “I would prefer my child take anabolic steroids and growth hormone than play rugby,” a British scientist who studies doping told the Financial Times. “I don’t know of any cases of quadriplegia caused by growth hormone.” The same is all the more true of American football, a beloved game that snaps the occasional teenaged neck and routinely turns the stars of the National Football League into shambling, pain-wracked, middle-aged wrecks.