Under the Microscope: It is impossible to live a life free of risk and uncertainty. Nevertheless we must strive to minimise the risks and uncertainties to which we are exposed by taking sensible precautions, writes Prof William Reville.
The key word here is "sensible". If we have inadequate precautions we expose ourselves to unacceptable dangers. If we go overboard on precautions we become obsessed with very small risks, suffer unnecessary anxieties and even take actions that damage society.
On the whole, society manages risk poorly. Experts advise, but the results are very disappointing. At least part of the reason for this is failure to differentiate between different kinds of risk and also the different mindsets people use to respond to risks.
Risks can be divided into three categories - directly perceptible risks, risks perceptible only with the aid of science, and virtual risks. Directly perceptible risks include things such as climbing trees, riding a motorcycle, and so on. Risks perceptible with the aid of science include infectious diseases. Virtual risks are those about which scientists cannot agree on their nature or magnitude. Suspected carcinogens fall into this category. I only have space to deal with directly perceptible risks in this article.
Each of us has an individual propensity to take risks and this can vary a lot from one person to another - for example this propensity is likely to differ significantly between a member of Hell's Angels and a school principal. In particular situations this individual propensity to take risks is modified by one's perception of the balance between the reward associated with the risk (e.g. drive faster and arrive sooner) and one's perception of the danger involved and of the probability of an accident occurring.
Efforts by the authorities to manage directly perceptible risks are constantly frustrated by the fact that people tend to be their own risk managers. This very often means that when new regulations are introduced to reduce risk, individuals react in ways that repartitions the risk between different categories, but in such a way that the overall risk is not reduced. Let us consider the familiar case of driving cars.
In 1995 the great British astrophysicist, Sir Fred Hoyle, accepted my invitation to give a public lecture at UCC. Fred was fascinating company because he had insightful opinions on many topics that came up in general conversation. For example, he told me that the time it now takes for a car to travel from Piccadilly Circus in London to the town hall in Brighton is the same as the time taken in 1850 by a horse-drawn carriage. He also said that road accidents increased in every country when mandatory seat-belt legislation was introduced. The reason for the first effect is modern traffic congestion and, for the second effect, more risky driving by belted-up drivers.
Nobody disputes that, in the event of an accident, a driver who is wearing a seat belt is better protected than a driver who is unrestrained. However, it is also true that the use of protective apparatus tends to encourage the user to take more risks. Thus, a trapeze artist who is using a safety net will attempt more adventurous manoeuvres than one who is flying without a net, a rock-climber using safety ropes will be more daring than an un-roped climber. The phenomenon is called "risk compensation".
More than 80 countries now have seat-belt legislation. However, the somewhat surprising fact is that, with the exception of the UK, statistics do not support total road fatality reductions as a consequence of mandatory seat-belt legislation. And some experts question the validity of the UK statistics. Seat-belt legislation seems to redistribute the burden of risk from the drivers of vehicles, who were already the most protected, to cyclists and pedestrians, who were already the most vulnerable. Not a good outcome.
I am all in favour of wearing seat belts. It is an effective way to prevent self-harm. However, it is important to distinguish between self-harm and driving in a manner that is a danger to others, e.g. driving at 80 mph in a busy built-up area. Legislation to prevent the latter behaviour is effective, legislation to prevent self-harm is not. The criminalisation of self-risk is only likely to redistribute the burden of risk in ways that injure innocent third parties.
We have evolved mechanisms to self-manage directly perceived risks. We automatically evaluate directly perceived hazards and individually decide how to handle them in a way that is the most comfortable for us given our propensity to take risks, our perceived rewards and our assessment of the risk and severity of accident. Central authority tries to reduce risk by providing structurally safe roads and by imposing various legally backed restrictions on our driving. Most people react to the restrictions with risk-compensation behaviour and consequently road accident statistics remain stubbornly high.
There is no shortage of evidence - road accident, smoking and sunbathing statistics, to name but a few - of the resistance that the public can display against the advice of experts. Institutional and national risk management is usually implemented without taking any account of the main reason people indulge in risk compensation behaviour, namely the perceived rewards of taking risks. It seems that significant further progress will be made only when this aspect is effectively dealt with.
William Reville is associate professor of biochemistry and director of microscopy at University College Cork