We live in a world of real dangers and imagined fears. The dangers are often low and falling, while the fears are high and rising. We are hounded by what I call "psycho-facts": beliefs that, though not supported by hard evidence, are taken as real because their constant repetition changes the way we experience life. We feel assaulted by rising crime, increasing health hazards, falling living standards and a worsening environment. These are all psycho-facts. The underlying conditions aren't true, but we feel they are and, therefore, they become so. Journalists -- trafficking in the sensational and the simplistic -- are heavily implicated in the explosion of psycho-facts. But so are politicians, policy advocates and promoters of various causes and lifestyles. Rarely does any of us deliberately lie. However, we do peddle incomplete or selective information that inspires misleading exaggerations or unwarranted inferences. People begin to feel that something's wrong, and this new sensation becomes an irrefutable fact or (worse) the basis for a misguided policy.

Crime? Yes, there's long been too much of it. But the best surveys do not show that it's dramatically worsened. Indeed, some victimization rates have dropped. The household-burglary rate declined by 42 percent between 1973 and 1991. The number of annual murders has fluctuated between 20,000 and 26,000 since 1980; the major increase occurred in the 1960s, when the number doubled. A Gallup poll reports that 86 percent of the respondents haven't been victims of violent crime. By contrast, our consciousness of crime -- fanned by local TV news -- has risen. "Are We Scaring Ourselves to Death?" asks ABC correspondent John Stossel on a recent network special exploring these issues. The answer is yes. But psycho-facts are seductive precisely because they are often plausible. We've been told for years, for example, that our living standards are dropping, and this became a big Clinton theme in 1992. It isn't really so. Over any extended period, our living standards have risen. In the past 25 years, median family income is up by about one-fifth. But the rise is much slower than we expected and so slow that it's often imperceptible or nonexistent in any one year. We don't feel it. Health, safety and environmental hazards inspire similar misconceptions. Suppose an experiment shows that substance X causes cancer -- at some dosage in some animal. We're soon worried that everything we eat or breathe is giving us cancer or heart disease. We feel that identifiable risks should be avoidable risks. We act as if there's a constitutional right to immortality and that anything that raises risk should be outlawed. Our goal is a risk-free society, and this fosters many outsize fears. Lots of theoretical dangers (like asbestos or plane crashes) aren't large practical dangers. The easiest way to grasp this is to glance at the adjoining table. It compares relative risks of dying. What's worth remembering is that roughly 2.2 million Americans die every year. With about 260 million Americans, this means that in a crude arithmetic sense the average risk of dying is about 1 in 118 (2.2 million goes into 260 million 118 times). Now obviously, the old die in much greater numbers than the young. Still, the general risk of dying from natural causes or unavoidable accidents is much greater than the specific danger of many hazardous substances or jobs. (The table shows both.) Alarmists will point out that all the specific risks of dying create the overall risk of dying. True. But no matter how much we reduce any specific risk, we'll still die from something, and many specific risks aren't very threatening. In the ABC program, Stossel tweaks Ralph Nader for seeing danger almost everywhere: hot dogs have too much fat; airplanes aren't adequately maintained; coffee has caffeine; rugs collect dust and cause indoor pollution. "Life is preparedness -- the old Boy Scout motto, be prepared," Nader says. The trouble is that if you spend all your life preparing, you may miss out on living. Of course, we should take sensible personal precautions and enact prudent safety and environmental regulations. But they should be sensible and prudent. We should not overreact to every ghoulish incident or conceivable danger. The abduction and murder of Polly Klaas late last year was horrifying, but so was the kidnapping of the Lindbergh child in 1932. Cloistering children in generally safe neighborhoods is not a sensible reaction. The old, too, often senselessly barricade themselves indoors against imagined crime. We "give up some freedom," as Stossel says. Likewise, misguided regulations based on exaggerated risk can waste lots of money. The asbestos panic was a costly mistake, as federal Judge Stephen Breyer shows in a new book, "Breaking the Vicious Circle: Toward Effective Risk Regulation." Leaving asbestos in buildings poses almost no hazard; removing it increases the danger by putting asbestos particles into the air. Breyer cites a toxic-waste case in which the company objected to the final cleanup. The site was already so clean that children could eat some dirt 70 days a year without significant harm. Why do more? "There were no dirt-eating children playing in the area," he writes, "for it was a swamp." The standard retort is: A rich country like ours can afford absolute safety. No we can't. Regulatory costs raise prices or taxes. Our incomes are lower than they might be. That's okay if we receive lots of benefits -- much cleaner air or healthier food. But it's not okay if the benefits are trivial or nonxistent. Good judgment requires good information. Every imagined danger or adverse social trend is not as ghastly as it seems. Consciousness-raising can be truth-lowering. We fall prey to our fears and fantasies. We create synthetic truths from a blend of genuine evidence, popular prejudice and mass anxiety. Psycho-facts are not real facts. We should try to tell the difference.