The law is not equipped to consider scientific disputeBMJ 2016; 352 doi: https://doi.org/10.1136/bmj.i1768 (Published 31 March 2016) Cite this as: BMJ 2016;352:i1768
In the first BMJ of this century I wrote an editorial criticising the conviction of Sally Clark for murdering her children.1 That conviction was based on the proposition that highly unusual coincidences don’t occur by chance—a mathematical fallacy disproved by every announcement of a lottery winner.
It took years to secure Clark’s release, and her health was so badly damaged in the meantime that she died soon afterwards. At that time, medical experts on both sides were united on one point—that the legal system couldn’t deal properly with scientific controversy.
This and other miscarriages of justice stopped when the expert witness Roy Meadow refused to give further evidence unless allowed to do so in a proper scientific way, describing uncertainty and the existence of dissent. Science doesn’t advance because scientists are right: it advances because every true scientist has at the core of her soul a passionate belief that she might be wrong.
But the law deals in certainties. Faced with scientific dissent, it considers the dissenters to be misguided at best. Why else would people deny what everybody in their discipline knows to be true?
The BMA’s call for a public inquiry
After the miscarriages of justice surrounding cot death, the BMA called for a public inquiry headed by a doctor or scientist into the judicial system’s failure to cope with scientific controversy. That didn’t take place. No lessons were learnt. Sooner or later, more miscarriages of justice will result.
These cases may share a desire to root out the evil of child murder, as well as a powerful consensus on the interpretation of evidence that is less certain than is widely believed, a few dissenters the prosecutors feel obliged to discredit, and a critique based significantly on knowledge from another discipline. Rather than the epidemiologists of the miscarriages of justice regarding cot deaths, shaken baby syndrome has engineers in place who challenge whether the necessary forces can be generated in the way described.
Our society is ever more intolerant of dissent, diminishingly at ease with itself, and increasingly of the belief that professional practice is improved by rigorous, unvarying compliance with evidence based consensus guidelines, which recognise no duty to treat the exceptional exceptionally.
When a system of quality control came to be applied to expert witnesses, the BMA warned that this might be difficult to apply in circumstances of scientific dissent. The warning was not heeded, and so the expert witness Waney Squier—the main dissenter on shaken baby syndrome—was convicted of professional misconduct.
She was apparently less than objective in some of her evidence. But I would confirm that, when you believe that innocent, grieving parents are being imprisoned for their bereavement because of scientific error, it’s not always possible to summon up the dispassion to which you might professionally aspire.
The duty of dissent
I don’t know whether Squier is correct; nor do I care. People have a right to be wrong, and without it no other human freedom is meaningful. The duty of dissent in the face of what you perceive as injustice cannot be qualified by a need to carry out a risk assessment as to whether you might lose the debate. The existence of dissent is something a jury is entitled to know.
The need for an inquiry into the way the legal profession deals with scientific uncertainty is as strong as it was when the BMA first called for it. That inquiry should be held before any more miscarriages of justice are occasioned by acceptance of scientific overconfidence.
For the avoidance of doubt, I do not assert that shaken baby syndrome is such a situation. I’m writing about dissent, not about shaken baby syndrome. I would not wish, especially in the current climate, to express an opinion beyond my areas of certified professional competence.
Competing interests: I have read and understood BMJ policy on declaration of interests and declare the following interests: I am a member of BMA Council.
Provenance and peer review: Not commissioned; not externally peer reviewed.
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