David Friedman can’t help but notice this phenomenon:
When the question of alcohol and health came up on “Doctor Radio”, a satellite radio program, all of the participants agreed that evidence showed that consuming a moderate level of alcohol, something like one beer a day for a woman, one or two for a man, or the equivalent in other drinks, was good for you, better than no alcohol at all. All of them also agreed that they would not advise their patients to do so.
Why? They mentioned that there were problems with prescribing something that depended on the exact dosage and that a higher level of consumption was likely to lead to auto accidents, but distinguishing one beer a day from three is not a difficult problem even for those who are not doctors. My conjecture was that the real explanation was the reluctance of doctors to appear to be on the wrong side. Everyone knew that alcohol was a bad thing, a source of auto accidents and various medical (and other) problems. By giving a truthful account of the medical evidence the doctors on the program might appear to be pro-alcohol; all good people are anti. Hence they had to qualify their conclusion as a purely theoretical matter, not something that would affect what they told their patients. Think of it as a different version of PC — Professionally Correct speech.
A similar pattern exists for ice cream. Multiple independent studies have found evidence that consuming ice cream reduces the chance of getting diabetes — and found ways of explaining the evidence away. In several cases they have gone so far, in public statements, as to report that yogurt is protective against diabetes, other dairy products are not, when ice cream in their study showed as strong, in some studies a stronger, effect than yogurt.
Yogurt, as everyone knows, is a healthy food. Ice cream, as everyone knows, is bad for you.
From time to time I see a news story on some piece of scientific research that somewhat weakens the case for taking strong action against global warming. I believe that every time I have seen such a report it was accompanied by a quote from the researchers to the effect that global warming was a serious problem and their work should not be taken as a reason to be less worried about it. They almost certainly believed the first half of that, but their work was a reason to be less worried even if not to stop worrying.
Good people are on the side that believes that warming is happening, is anthropogenic, is a serious problem that needs to be dealt with immediately. Bad people deny one or more of those claims. If that is what all the people who matter to you, such as the fellow members of your profession, believe, and you are so unfortunate as to produce results that strengthen the bad people’s case, it is prudent to make it clear that you are still on the side of the angels. Just as, if you are so unfortunate as to be an honest doctor aware of the evidence in favor of alcohol, it is prudent to make it clear that you have not transferred your allegiance to demon rum.
