One of the arguments you hear too commonly these days is: “The science is settled.” Actually, it’s not an argument at all. It’s more a case of: “ ‘Shut up,’ he explained.”

Science is never settled. The possibility of new facts or interpretations coming to light cannot be ruled out. Ask Isaac Newton.

However, even when nothing revolutionary has happened, our knowledge base is still less reliable than we think.

Last month, the journal Science reported a major re-examination of 100 famous psychology experiments. A team of researchers tried to recreate the findings of these experiments, and found that in 62, the results could not be replicated.

Yet one of the requirements of any valid scientific thesis is that it can be tested numerous times, and the same result will always follow.

Psychology is not alone in this emerging trend of unreproducible “discoveries.” A few years back, a major paper alleging some link between vaccination and autism was discredited and the author lost his medical licence.

In 2014 the journal Nature had to retract a study on stem-cell reproduction. The data had been fiddled, and one of the authors subsequently hanged himself.

A heart researcher at Harvard Medical School used fake numbers in almost 100 published papers over a 14-year period before being nailed.

Numerous reports linking certain pesticides to cancer have been withdrawn. And claims to have discovered human-like monkey intelligence blew up when a federal investigation in the U.S. found the author guilty of fraud.

These are by no means mere anecdotes or exceptions to the rule. One authoritative study found there has been a 10-fold increase in retractions by scientific journals over the past decade. The pressure to “publish or perish” is no doubt part of the story.

But so is the huge proliferation of publications — now well over 10,000 — and a consequent dilution in quality control and oversight.

Does any of this matter in our daily lives? Absolutely. The provincial Education Ministry is introducing a controversial new curriculum that many fear downplays disciplinary knowledge behind a smokescreen of edu-babble.

And the basis for this brave new world? Child psychology.

Likewise, the Health Ministry is promising to bring in a program of redeemable points for seniors who follow healthy lifestyles.

But how sure are we about what constitutes a healthy lifestyle? At the extremities, no doubt we are. Smoking two packs a day will kill you (or it should). Ditto chugging shooters until you pass out.

But what about dietary cholesterol, such as eggs contain? We’ve come full circle on that.

And what counts as high blood pressure? The standard used to be 120/80, but some physicians believe higher rates, perhaps up to 150/90, might be tolerable in older patients.

Is jogging good for the heart, or ruinous on the hips and knees?

There is even a debate about the impact of dietary salt. That’s not to say large quantities are advisable. But it’s safe to note there are points of uncertainty here, as well.

And this is the real reason for concern. The disciplines most susceptible to iffy research tend to be the soft sciences — psychology, economics, political science, population health, etc.

But these are the fields most directly linked to public policy. If some crank thinks those points of light, found by NASA on the dwarf planet Ceres, suggest an alien presence, so what?

But I would prefer not to have the Health Ministry auditing my lifestyle based on some fad of the moment. Extraordinary claims are supposed to necessitate extraordinary evidence.

Similarly, public policy that steps heavily into our private lives had better be extraordinarily secure. How that is to be achieved amidst widespread scientific fraud, I have no idea.

jalmcfarlane@shaw.ca

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