The danger of following ‘the science’

I have decided to divorce my wife after 31 years on scientific grounds. Though perfectly happy, on reassessing my original decision to enter matrimony it has emerged that at no point was that choice subject to peer review, there was no randomised control trial, the experiment could not be replicated and the data-set on which I based my decision failed to provide the levels of statistical confidence required.

I don’t think my decision to marry was bad, but it was definitely unscientific. Most important decisions are. Indeed if one phrase has most irritated me in the past few months, it is ‘the science’. What is ‘the science’ on masks? The implicit assumption is that we can only act on generalisable, definitive facts. This is unsafe in the instance of Covid, since a combination of medical ethics and short timescales means we still don’t know most of what we need to know in order to develop nuanced models and reliable recommendations. Science’s arbitrary p-value obsession also runs counter to real-world decision-making, where trade-offs must be made between the reliability of information and the consequences of acting on it. If business demanded scientific levels of certainty in decision-making, the economy would collapse. There is no Isaac Newton for ‘Should I open a Turkish restaurant in Bromley?’ because, in reality, what you don’t know is always more critical than what you do.

Let’s take face masks. One thing we don’t seem to know is the path dependency of Covid-19. In particular we don’t know if the size of the initial viral dose has a bearing on the course or severity of the disease. Most models appear to assume that infection is a binary matter. But if this is wrong, it is possible masks may do double duty by not only reducing the rate of cross infection but also improving outcomes — and even the rate of onward transmission — among those infected.