Iain Gray: The science of understanding an argument

Casual links are fundamental to ensuring a more educated approach to our political policy, writes Iain Gray

Some may prefer the Danish noir of Borgen, but for most Scottish politicos the West Wing TV series remains the politics masterclass. They should pay more attention to the very first (post-pilot) episode, Post Hoc Ergo Propter Hoc. President Bartlett lectures his staff on the fallacy of the Latin aphorism which means, “After, therefore because of”. He admits that he was photographed in Texas in a silly cowboy hat, and then lost the state. But he did not lose because of the hat. He chides staffers for naively assuming a causal link. Politicians are prone to post-hoc reasoning and dubious causal links. It is one of the reasons they do not understand science, and that matters.

Ten years ago flawed science claimed that children developed autism because they had previously had the MMR vaccination. Rigorous studies demonstrated no causal link but some politicians pandered to seductive post-hoc reasoning. Nicola Sturgeon, then shadow health minister – described a Scottish Executive report showing that there was no link – as a “whitewash”. Now in office she has to encourage the vaccination of university students who missed out when vaccination rates plummeted in the scare she herself flirted with.

On this kind of issue politicians usually demand 100 per cent proof that there is no risk, 100 per cent certainty of safety. This just shows again that politicians do not understand how science works.

It is especially disheartening to hear that demand for certainty in the Scottish Parliament, in the very city where David Hume made clear centuries ago that no scientist could ever claim 100 per cent proof. Hume said that if every swan you have ever seen is white, you can hypothesise that “all swans are white” but you can never be sure that the next swan you see won’t be black. Nothing can prove your theory right, although one black swan will prove it wrong. So scientists will never say they have absolute proof.

In fact science is even more profoundly uncertain than Hume imagined. In Hume’s day Newton had shown that if you knew where all the particles of the universe were and what forces were acting on them you could calculate exactly where they would be at any time in the future. Today’s quantum physicists know there is no such certainty, only probabilities of different outcomes. That is why the Higgs Boson was only “discovered” with a 90 per cent probability. Science tells us the world is fundamentally uncertain, whether politicians like it or not.

Years ago, with another MSP, I met a group of schoolchildren who had studied the controversy over genetically modified crops and food. When one pointed out that most scientists seemed to think GM foods were safe, my colleague responded that this could not be trusted because “these were the same scientists who told soldiers at atom bomb tests they would be safe if they turned their back”. This was followed by the inevitable, “we should not allow GM foods unless there is absolute proof that they are safe”. When I pointed out that not only was this an attack on all scientists, but also an argument against all scientific research, I was met with incomprehension.

One aspect of science which politicians might be expected to understand is that scientists disagree, all the time. When new ideas topple old ones, it begins with a few “early adopters” until a consensus begins to emerge. A complex system of peer review of research is designed to ensure that those new ideas have a strong foundation of argument and evidence.

Peer review means that scientific consensus is underpinned by significant, rigorous evidence. Once again politicians do not get that – unless it suits them.

Writer and one-time green activist Mark Lynas recently criticised Green politicians pointing out that they demand that we accept the scientific consensus on climate change. Yet they refuse to countenance the worldwide scientific consensus that GM food is just as safe as any other. Outlier scientists who question climate change are denounced in apocalyptic terms as “deniers”, but equally isolated anti-GM voices are lionised for standing up to the Establishment. Even more contradictory, given their zeal to reduce carbon emissions, are the contortions green groups perform to refute the established scientific consensus that nuclear power is the only safe, quick way to do just that.

Similarly, the Scottish Government berates anyone who doubts that our engineers will imminently solve the technological problems of marine energy, but refuses to listen when the same engineers explain that government sums on renewable energy make no sense.

Lynas has called the SNP’s ban on GM “a betrayal of the values of the Scottish Enlightment”. I do despair of politicians who delight in Scotland’s history of scientific achievement and then so readily mistrust scientists and so wilfully misunderstand science itself.

We can start to build bridges of understanding between politics and science. In parliament a cross-party group has begun work.

I have also asked the Royal Society of Edinburgh to start a pairing scheme, where MSPs and scientists would spend time shadowing each other. The Royal Society has such a programme, but only for MPs.

Moreover, the public needs protection from bad science too. Why not teach scientific method explicitly in schools as part of the Curriculum for Excellence? Every citizen depends on decisions about the science of energy, food, medicine. Some pupils will even grow up to be politicians. It would be good if they understood a little more about how science works.

• Iain Gray is Labour MSP for East Lothian