Comment
Beware of evidence prepared to support entrenched views
“Let’s hope a wiser and more informed approach will emerge in the forthcoming parliamentary ” committees
I a recent though ul article about public trust in politicians, James Hohmann, writing in the Washington Post ewsletter, paid homage to the adage Credibility is like virginity, you only get to lose it once.’ While this may be a statement of fact, it le me cogitating over what it really means in the modern social environment, where narrowly framed but strongly promoted opinions o en impact disproportionately on public policies.
At a simple level, you might argue that if a scientist, policy maker, politician or lobbyist consistently gets things wrong their credibility would soon be shot and their opinions ignored.
However, both casual observation and some well documented examples demonstrate that is by no means the case.
The media and, perhaps more disturbingly, the politicians o en become beguiled by the loudest voiced, issue driven advocacy, and the consequences in social and economic terms can be very damaging.
There is particularly an issue where the advocacy is being underpinned by scientific research, and politicians argue that they can only be guided by the science’.
Throughout history there have been examples where scientists and others with the ear of politicians have presented their findings as irrefutable facts, when they have really been theories or beliefs.
As a scientist, I will always argue that truth will ultimately out. However, it would be na ve to suggest that evolving scientific theory and observable facts are always completely aligned.
It is tempting to think that these discontinuities between understanding (based on theory) and observable facts are usually small and quickly corrected. But that is not the case.
For example, it has become progressively apparent that policies and guidelines on human diet and health have been disastrously wrong for years, and the impact has made a major contribution to the current public health crisis.
There is a modern tendency to blame this problem on the widespread acceptance of the work of American physiologist Ancel Keys, who in the 1960s and 1970s misguidedly and myopically focused public health attention on the claimed adverse health impacts of dietary saturated fats.
However, a new book, Healthy Eating The Big Mistake, by erner Wheelock, a former colleague, provides a much broader and fuller understanding of the situation.
In an extremely well researched analysis, Wheelock highlights a long catalogue of instances where the human nutritionists and public health specialists involved made important underlying misjudgements and wrong turns over half a century, inadvertently and indirectly creating many of the public health problems that are now of major concern.
So how could this happen among well qualified professionals in their specialist fields Why didn’t they lose their credibility along the way
Well, the constant theme in Wheelock’s findings is that the researchers were very effective and very focused in presenting and promoting the results that fitted with their theories. However, in numerous instances, they simply ignored observable facts that did not.
This may appear a hugely damning criticism, but it should not be entirely a surprise. Psychologists since the late 1950s have recognised that human beings strive for internal consistency to allow them to function mentally in the real world.
When people are presented with new evidence that conflicts with their established view they either accept it and change their view or ignore it, allowing their established view to prevail. This avoids the stress of what the psychologists refer to as cognitive dissonance.
The important lesson for scientists and policy makers is that different scientific methodologies, including intervention studies, experimental hypothesis testing, and observational measurements in practice, all have a valid role in generating factual evidence and it is essential to integrate all the evidence into their framework of understanding.
Unless that is done, the framework of understanding is likely to be wrong headed and lead them in the wrong direction.