A letter has come in from Peter van Schaik joining the debate about bicycle helmets. Mr van Schaik has used statistics from the ACT Department of Health to show that since bicycle helmets have been made compulsory the number of injuries sustained by cyclists has gone up and the injured cyclists were staying longer in hospital.
He argues that helmets result in people riding faster or more recklessly because they have been lulled into a false sense of security.
At first blush it might seem that helmets give greater protection and therefore injuries should fall. But the world is more complex than that. An American academic, Gerald Wilde, lends support to Mr van Schaik. He has developed what he called Risk Homeostatis Theory.
The theory starts with the proposition that all human activity carries risk and benefit. Fast travel is risky but it brings the benefit of saving time. Wilde suggests that humans are quite prepared to expose themselves to a fairly static level of risk in order to maximise benefit. People will drive slowly on a dirt road, a little faster if it is paved, faster still if there are white lines down the side and faster still if the road is divided. If they drove a dirt-road speed when the road is paved, there would be virtually no prangs. The driver maintains what he sees as an acceptable level of risk but varies his conduct to get greater benefits.
Wilde points out that humans are not very good at assessing risk. Conduct changes according to perceived risk, not real risk. Cyclists, compelled to wear helmets, probably think they are less likely to be severely injured, so go faster, almost sub-consciously. Wilde draws on a huge number of studies to illustrate his point. The most pertinent was when Scandanavian countries swapped from driving on the left to driving on the right. Everyone throught that the move was fraught. Idiots would drive on the wrong side and prang into each other. The result was a lower rate of accidents immediately after the swap because everyone drove that much more carefully.
He cited examples of how people who had done advanced driving courses or had non-skid brakes fitted had more accidents. They emerged from their classes cocksure of themselves and smashed up their cars. He has argued that virtually every so-called safety measure, taken in isolation, has merely been met with humans changing their conduct while keeping their acceptable level of risk the same. Better roads and cars only lead people to squander the safety dividend to get the benefit of arriving earlier. A safety net merely encourages carelessness.
Wilde has some pertinent things to say about the media. He says media organisations are obsessed with the extraordinary. Someone spraining an ankle in a parachute jump gets a few paragraphs, but someone spraining an ankle while putting out a big bin is not news. As a result we get a perverted view of what things are dangerous, and what are not. Shark attack is a case in point. The one or two attacks a year are reported in great detail, and people wrongly imagine that being eaten by a shark is a likely risk. In fact, it is far more risky to go into the surf with three or four cans of beer under the belt than to swim amid a few sharks.
Car accidents are too commonplace to report much, yet cars are far more likely to injure and kill us than most other sources of violence.
Wilde argues, we need more knowledge about risk and to translate that knowledge into changing conduct so that excessive risk is avoided. Safety measures on their own are not enough. All they do is lull us into a false sense of security. It is no good putting on a seat belt if you drive faster as a result.
The death and injury rate from car accidents in Australia has steadily fallen over the past two decades. If I read Wilde’s theory correctly, it is because in addition to seat belts and “”safer” cars and roads, drivers have changed their conduct for the better because of a new penalty for risk: fines and licence cancellation.
Cycle helmets, though, are different. There has been no concomitant penalty for humans using up the benefit of helmets by cycling more furiously. Helmets on their own have apparently encouraged carelessness.