The full dope

At Crooked Timber, I read this about Michael Crichton's recent speech to Caltech about junk science:

"Caltech can't be held fully to blame for Crichton's speech; universities rarely know in advance what their guest speakers are going to say. But it should be a lot more careful about whom it chooses to deliver major talks in the future."

And I said:
I had to double-take when I saw that. The best way to prove a man who says the consensus silences its critics is to call for him to be silenced?

Jeez.

Crichton is largely wrong about how science makes progress (but Lakatos, while improving on Popper's description of how science progresses, hardly proved him wrong about what is scientific), but he surely isn't wrong to suggest that scientific faddism is as prevalent as pseudoscience.

...

I could have added:

Where Crichton was not wrong is that science is often used and misused to political ends: 'twas ever so. Scientists - or quasiscientists - can be induced to lie, or at least to manipulate the truth, in a political cause.

The latest big deal in the UK is cannabis-induced psychosis. The papers are full of anecdotes about kids who had some strong skunk and became schizophrenic. Some of the people writing the anecdotes have been doctors, others "scientists". I'm awaiting the first "Reefer Madness" headline, but it can't be far off.

There has been a great deal of research into cannabis and mental illness. Studies show that cannabis use is a risk factor for schizophrenia (although it's not highly correlative) and psychosis (however, it is unusual for their to be cannabis psychosis in the absence of other drugs). Generally, there's risk if you eat a big chunk too. This isn't news to users, of course. We've all seen people have more than they can handle and get edgy. We've all been a bit para after a smoke of something strong.

So, there's a risk. We'll leave aside the argument that the correlation between cannabis smoking and mental illness might work the other way round (that the mentally ill are more likely to smoke dope, rather than that the dope smokers are more likely to be mentally ill) and accept that it's risky.

But risk is not an absolute to be avoided. It ought to be quantifiable, and weighed against benefits if you like to help decide whether an activity ought to be pursued.

As an example of what I mean, take mortality in childbirth. In the UK in 2000, 1 in 3300 women died in childbirth or of complications of pregnancy. That makes childbirth a risky business, huh? Surely, Mrs Zen should get rid of the kids now? Her risk of dying in a termination would be lower (though not much, I think).

But there are benefits, of course, and they need not be spelled out. We understand that the risk of dying in childbirth is worth taking. (How that understanding would be affected, though, were doctors to take to writing series of stories in the Daily Mail about how their patient snuffed it giving birth, rather than the one-off shocker it treats us to now and then, is something to think about.)

What none of the doctors who entertain us with their "Keep kids away from killer cannabis" beat-ups ever address themselves to is the facts and figures. How many cases? At what dosages? How many cases per dose? How does cannabis compare with other socially acceptable drugs? You can certainly have an alcohol-induced psychosis (as anyone who's witnessed Mrs Zen after a Black Russian too many will testify).

This is just the beginning. They'll need to establish how cannabis interacts with other risk factors, whether it increases existing problems or causes new ones, and blah de blah de blah.

Crichton was not wholly wrong about global warming. Too many people are willing to reduce a difficult subject to a scare story. To say that doesn't mean the same as saying there is no global warming - there is absolutely no doubt that there is, and anyone who claims that it is in doubt is a charlatan - but what it is, and what it means for our health are as slippery as cannabis psychosis. What Crichton ignored, of course, was that not knowing how scary something is works both ways.

Global warming might turn out to be reasonably unimportant, a small drop in the huge ocean of climate change (although I doubt it, and the evidence that I've seen, at least, points to at least some cause for concern, if not the shrieking hysteria that characterises most debate about it). But if it doesn't?

posted by Dr Zen @ 3:10 am