Conservative Means Never Having To Say, "I learned I was mistaken about something."

Absent real data, a conservative temperment is useful to have around. "Don't go changing everything based on your half-baked ideas," is frequently the exact right thing to say to a child or a policy maker. 

But what about when we do have data? Is there a tipping point where conservative temperment is simply a nice way of saying, "someone who will never change his mind, no matter how much our knowledge advances"?

I'm thinking in particular about a post on the Well Blog at the NYT where the data says, quite clearly: eating carbs instead of fat causes behavior changes including less exercise! They then found an old man who had studied obesity for 60 years to say,

It won’t work, and neither will changing the source of calories permit us to disobey the laws of science.

He might as well have said, "Fuck experiments, I'm an expert and I'll tell you what science says! And you'll like it!" (Read the madness here.)

I was reminded of this reading this post by Mark Kleiman about a travesty of science-lying committed in a press release about a marihuana study.

The study data could have been described in a straightforward manner: a group of moderately high marihuana users had brain structure differences from non-users. Unanswered questions include: Good differences? Bad? Use caused changes? Differences caused use? To be discovered later.

But how else might it be described?

If instead you wanted to score points in the culture wars, push your political agenda, and perhaps please your sponsors at the National Institute on Drug Abuse and the Office of National Drug Control policy, you’d behave differently.

First, you’d assume that all measured differences represent “abnormalities” among cannabis users: for example, both increased gray-matter density in some brain regions and decreased gray-matter density in other brain regions. You’d ignore the fact that your study hadn’t found any functional differences between the two groups. You’d use the loaded term “abnormalities” rather than the neutral term “differences” in the title of your paper. Second, even if the journal reviewers made you put in some weasel-words about not being able to make any causal inference (because the study was purely correlational, with neither a controlled intervenion nor a longitudinal design) you’d still put out a press release that makes it sound as if you’d found something very scary, “a strong challenge to the idea that casual marijuana use isn’t associated with bad consequences,” : (remember, no actual bad consequences of any kind were found). Pretending that the findings to “casual” cannabis user would require that you gloss over how extreme your sample was: an average age of onset of just over 15 (very young exposure is known to be correlated with higher risks) and cannabis use of a minimum of a joint a week and an average of 11 joints a week. (The median cannabis user consumes once a month; once a week – the minimum in this study – puts someone in the top quartile, while 11 joints a week would put someone in the top 15%.) Instead, you’d describe your findings as applying to “recreational” or “light-to-moderate” cannabis use. And just in case anyone had missed the point, you’d claim that “further study of marijuana effects are needed to help inform discussion about the legalization of marijuana.” (And of course you’d get away with it, though an alcohol researcher who tried to put in a plug for higher alcohol taxes in a paper on alcohol-related violence would almost certainly get slapped down.)

But it was this following last bit that makes you wonder if conservatism is like essentialism or racism in that it's a particular habit of wrongness:

Update: The lead author on the paper seems to be innocent of any political purpose. The scare quotes in the press release come from the last-named author, who is also the most senior person on the team.

In other words: the old guy who has been doing this for awhile is also the person least interested in following the data wherever it leads. He already knows.