Virtual risk and the myth of value-free science

When human ingenuity is driving us ever-faster into an age of uncertainty, the old rules of risk assessment no longer apply. It calls for a new kind of science policy - and some creative humility from scientists,argues Jonathon Porritt. Business people have become very fond of the adage that ‘you can’t manage what you can’t measure’. Now policy-makers are beginning to realise that this applies just as much to risk as it does to business strategy. It sounds straightforward. But the trouble is we’re just too damn clever. Our ability to manipulate and recombine molecules (in a seemingly limitless array of new synthetic materials), not to mention DNA, accompanied by an enduring capacity to ‘screw up’ in an unforeseen way, makes it much harder to assess risk using the old-fashioned techniques of calculating statistical probability.

Which leaves policy-makers uneasily marooned in the zone of ‘virtual risk’, where assertions of statistical probability amount to little more than expressions of uncertainty. And this can be a minefield for public decision-making.

In his excellent book, Risk, John Adams uses the 1995 contraceptive pill scare as an example. Based on preliminary evidence, the Committee on the Safety of Medicines issued a warning that the latest generation of oral contraceptives was “twice as likely to cause blood clots” as the previous generation. Something resembling a national panic ensued, and a large number of women stopped taking the pill, leading to an estimated 8,000 extra abortions and an unknown number of unplanned pregnancies - both of which carry a far higher health risk than staying on the pill. Only subsequently did it emerge that this doubling (which sounds pretty serious) would result in no more than two extra fatalities a year, with the death of 5 out of every 1 million women on the pill instead of 3 in a million. Even Kenneth Calman, the government’s chief medical officer at the time, admitted that this was hardly the best example of responsible risk management.

As John Adams says, “science has been very effective in reducing uncertainty, but much less effective in managing it. A scientist’s ‘don’t know’ is the verbal equivalent of a Rorschach ink blot: some will hear a cheerful, reassuring message, others will listen to the same words and hear the threat of catastrophe.”

So pity our poor policy-makers wrestling with the need to make ‘evidence-based’ decisions, when the evidence often isn’t there. With GM crops, for example, there is simply no way of assessing the potential risks involved in releasing genetically modified organisms into the environment. There is no ‘predictive ecology’ to allow experts to hypothesise about downstream impacts on other species - and there would appear to be very little interest in developing new risk-assessment techniques on the part either of government or of the biotech companies.

We encounter similar problems when trying to assess the impact of certain GM crops on human health. When Friends of the Earth USA recently discovered that GM maize grown for use in the animal food chain had somehow got into the human one (in a popular brand of corn chips), no amount of emollient damage limitation by the Food and Drug Administration could give consumers the reassurance they wanted. There simply wasn’t the hard evidence. And ‘experts’ on both sides could only speculate about the possible impact on human health of the ‘novel proteins’ that this particular brand of GM maize now contains.

Don’t get me wrong: this inherent uncertainty should not be construed as a charter for scare-mongers and neo-Luddites. But it should deter pro-GM scientists, as the self-appointed guardians of so-called objective truth, from making arrogant and unfounded claims about safety and relative risk.

And not only because this would be bad science. Post-BSE, both consumers and environmentalists would appear to have become increasingly resistant to the so-called ‘objectivist approach’ involved in all such top-down risk hierarchies. What we’re talking about now is a much more ‘constructivist approach’. This, in short, means scientists getting down off their high horses and mixing with us ordinary folk to try to make better sense of these complex issues. Which is precisely what the UK’s Royal Commission on Environmental Pollution (RCEP) was saying in its October 1998 report, when it called both for greater public involvement in risk management, and for greater responsibility on the part of that same public in learning to handle more sophisticated risk assessments.

It also means that we can dispense once and for all with the myth of ‘value-free science’. All sorts of scientists who really should know better pontificate away about science being totally objective. They stress the distinction between scientific research itself and the application of science, the former being ‘without ethical content’ and the latter more of a political, value-laden issue than a strictly scientific one. The philosopher Philip Sherrard makes short work of this particular fantasy:
“There’s one particular fallacy from which we must free ourselves, and this is the idea that contemporary scientific theories are somehow neutral, or value-free, and do not presuppose the submission of the human mind to a set of assumptions or dogmas in the way that is said to be demanded by adherence to a religious faith. Every thought, every observation, every judgement, every description, whether of the modern scientist or of anyone else, is soaked in a priori preconceived built-in value judgements, assumptions and dogmas at least as rigid, if not more rigid (because they are so often unconsciously embraced) than those of any explicitly religious system. The very nature of human thought is such that it cannot operate independently of value judgements, assumptions and dogmas.”

The persistence of the ‘value-free science’ myth has had a pernicious influence on many aspects of policy-making. If governments really want people to have confidence in their regulatory structures, then it would be sensible not to stuff the relevant committees with ‘experts’ who have transparently vested interests in those areas of concern. Yet their presence on those committees is often justified on the grounds that they will treat all issues coming before them in a wholly dispassionate and ‘value-free’ way. Those who point out the obvious absurdity in these arrangements are themselves dismissed as politically motivated, anti-science and biased.

So full marks to Michael Meacher and other ministers who have reviewed all the committees dealing with GM crops, and introduced a much greater diversity of people and interest groups. There’s particular interest in the new Agriculture and Environment Biotechnology Commission, which reports to Mo Mowlam in the Cabinet Office, and which has a specific remit to look at many of the issues relating to risk, public perception, values and ethics.

It will take a long time for these reforms to work their way through into greater trust of the scientific establishment. And it really doesn’t help when leading scientists constantly resort to the accusation that those who have different opinions from them are ‘ignorant’ or ‘emotional’ or even ‘hysterical’. But apart from the media, nobody benefits from a climate of automatic, unthinking cynicism and mistrust - least of all those who depend on good science for good decisions.

It’s just not as easy as it once used to be, either for scientists (giving advice) or politicians (interpreting that advice). ‘Sound science’ remains as elusive a concept as ever: public confidence in scientists has fallen markedly, and the knowledge gaps between the experts and the rest of us grow ever larger. We are all struggling to make sense of a process of technological change so rapid that it permits us no breathing space. That breakneck pace is itself one of the most significant elements in a widely-shared perception that the world seems to be getting riskier - rather than safer.

Jonathon Porritt is programme director of Forum for the Future, and author of Playing Safe, published by Thames and Hudson, price £6.95, 020 7845 5000;
www.thameshudson.co.uk

28 May 2001

Jonathon Porritt