It starts with something called the
Peltzman effect which Almighty Wikipedia defines as "the hypothesized tendency of people to react to a safety regulation by increasing other risky behavior, offsetting some or all of the benefit of the regulation."
(...)
Likewise, there are multiple studies showing that bicycle helmets, in the long run, don't actually reduce the number of injuries. In 2006 a researcher in Bath, England posted up the results of a study showing that when bicyclists wear safety equipment like helmets,
people in cars are more likely to hit them. A scientist/test subject found that motorists came an average of 3.35 inches closer to his bike when he rode protected. The sight of the safety gear turned off the common sense part of their brain.
Still, you'd think that in the long run, there'd
have to be health benefits to head protection. After all, some countries, like Australia, have made helmets mandatory for all cyclists. A
bunch of states in the U.S. have bike helmet laws, and the fight for helmet laws in other states rages on. Some people think it's weird that the government can tell you what kind of hat to wear during a certain activity, but at least bike fatalities have gone down. They
have gone down, right?
Not according to science. Recent studies from
Australia suggest that mandatory helmet laws have the
opposite effect. Between 1982 and 1989 -- prior to the helmet laws -- the country saw its number of cyclists double (bicycles actually give pedestrians a decent chance of outrunning the crocodiles and flying jellyfish). You'd expect bike-related injuries and fatalities to have shot up during the same period.
Instead, they
dropped -- deaths plummeted by 48 percent, while injuries fell 33 percent. This seems a little counter-intuitive until you account for human behavior. More people riding bikes leads to motorists who get used to sharing the road with them. But then, in 1992, they passed the laws making bike helmets mandatory. It was a disaster. 1995 and 1996 saw higher numbers of cyclist head injuries than any year prior to the law's passage.
How is that possible? Well, the fashion consequences of mandatory helmets caused the women of Australia to
stop cycling. Apparently they valued the hair on their head more than the brain inside it. Since there weren't any girls to impress,
the boys stopped cycling too.
Cyclists are rarer, motorists are less likely to be on the lookout for them, so there are more accidents. And -- to make it even worse -- you lose the health benefits you were getting from cycling. In total, Macquarie University found that Australia's helmet laws cause as much as
half a billion dollars in health-related costs every year. It doesn't matter what kind of data you get from a helmeted crash test dummy; a real human just doesn't want to look like a dork.
