The Surprising Risks of Playing It Safe


Feb. 22, 2007 — -- Deaths! Injuries! People are hurt every day. This is unacceptable, isn't it? We should do something about it. And when people want something to be done, they usually say that "there ought to be a law."

And so we get more laws meant to make us safer. Because 700 Americans die in bike accidents every year -- that's two a day -- lots of places now have passed laws requiring every biker to wear a helmet. It seems only sensible, since head injuries are what kill people. Public service announcements tells us that "a properly fitted helmet cushions the blow, protecting the head and brain from injury."

So helmets should protect people … like me. For years I've ridden my bike to work, and for years I rode without a helmet. It was probably very dangerous. "20/20's" offices are in New York City, which means I had to weave in and out of traffic, hoping I didn't get hit by a car. This year, I finally started wearing a helmet. I wasn't forced to, New York has no law requiring adults to wear them, but my friends talked me into it, and frankly, I was surprised to discover that today's helmets are better; they're actually comfortable.

But does my helmet make me safer? Maybe not, because safety measures often have unintended consequences.

Ian Walker is an avid cyclist and a human behavior researcher at the University of Bath in England. He set up a bike with an ultrasonic distance sensor and camera, and rode for miles with and without a helmet. His data showed that cars reacted differently when he had the helmet on.

"When I wore a helmet, there was a quite considerable tendency for drivers to get closer," Walker said.

What's the reasoning, I wondered? Is it because a driver thinks, "Oh, that rider has a helmet. … If I hit him, he'll live?"

No," Walker said. "It's that they're saying, 'He knows what he's doing.' When they see a cyclist who has all the gear, they think it's a sign of someone who's experienced and skillful."

Walker found that 23 percent more cars came within three feet of him when he wore a helmet. And, he says, there's another unintended consequence of helmet laws: fewer cyclists.

"Parts of Australia, Canada and New Zealand have made bicycle helmets a requirement. What you see is that when you make them a requirement, the number of head injuries among cyclists in those countries drops off," he said.

That sounds great, right? Fewer head injuries is a good thing. Well, not so fast.

"The number of cyclists is dropping off at exactly the same rate." Walker said.

Assuming these former cyclists don't rush out and start doing other exercise, that's not a good thing.

"When people don't cycle, they're not getting exercise," he said. "We know that not getting exercise and being sedentary is incredibly dangerous. You get heart attacks, you get strokes … proven killers that kill thousands of people. So when people make helmets a requirement, with the best intentions, it may actually kill more people."

And here's another unintended consequence. Now that I wear a helmet, I feel safer. So I've noticed that I take more risks. I ride in traffic more often. Economists call this the "Peltzman Effect:" the idea that people adjust their behavior in a way that counteracts the intended safety effect.

Unintended consequences of well-intended safety rules are not unusual. In 1972, the FDA passed a law requiring child safety caps on many medications. It was supposed to keep kids from getting into the medications -- especially aspirin. Kids can still open them, but it's tougher.

So, requiring safety caps sounded like a great thing, but there was an unexpected side effect. Because these safety caps are often so hard to get off, some people -- particularly older people -- just leave them off altogether, and some parents, feeling protected by the cap, leave the aspirin where kids can reach it.

A study on the "lulling effect" concluded that an additional 3,500 children have been poisoned by aspirin because of the regulation.

A second example: You may have seen the warnings about anti-depressants. The FDA demanded that a black box be added to every package. The unintended consequence? Prescriptions to anti-depressants dropped 20 percent. And with fewer teenagers taking the medication, many experts say they are seeing more teen suicide.

And here's an odd one. Most of us, when we have a new baby in the house, make an extra effort to keep the house especially clean. I was no exception. But now there's research suggesting that kids who are exposed to more endotoxins -- mild dust, bacteria, pollen, like kids who go to daycare or have pets or live on farms -- are less likely to develop allergies and asthma.

This could be why my daughter Lauren got asthma. She often had to use a ventilator when she was a child. … Maybe my wife and I were responsible.

I'm relieved, though, that my daughter doesn't blame me.

"I don't think you did keep me too clean," she said, laughing. "If anyone did, it was mom."

So, a sterile house, safety caps, warnings, helmets -- all mean well, but you never know what the unintended consequence will be.

And here's a final bizarre idea from Ian Walker:

"When I was doing the study, it wasn't part of the original plan, but a lot of people asked, 'Do you think this would be different if you were a woman?'" he said.

To find out, he ran his test wearing a wig. He rode for miles, and measured how close the cars came.

"I found that when, from behind, I looked more feminine, I got quite a lot more space from overtaking vehicles," he said.

Could a wig be a safety device? I tried it. I bought a blonde wig, put it on, and then took my usual route to work. To cars passing me from behind, I appeared to be a woman. To everyone else, the blonde wig and black mustache were probably startling. I couldn't tell if cars came closer or not. I think I was too embarrassed to even look.

Frankly, I don't care how safe a wig will make me; it's not worth it.

ABC News Live

ABC News Live

24/7 coverage of breaking news and live events