Re: I crash into religion
In article <firstname.lastname@example.org>,email@example.com
> Espressopithecus (Java Man) wrote:
> > In article <firstname.lastname@example.org>,
> > email@example.com says...
> > >
> > > Espressopithecus (Java Man) wrote:
> > > > The last time I went on a 25 km walk, there were no bicycle helmets, so
> > > > the question is moot.
> > >
> > > That sounds like a rather desparate evasion.
> > Facts are not a desperate evasion.
> You were hairsplitting to avoid admitting you would never consider a
> helmet for a 25 km walk. In that context, the "fact" was merely a
> delaying tactic.
I am suspicious of the population statistics on risk while walking and
cycling, and don't use them to make decisions about my own exposure. I
am convinced that individual risk-taking behaviour varies greatly
between individuals, and that the underlying risk distribution in the
population has a very high sigma. Unfortunately I no longer have the
reference, but I reviewed ~ 25 years ago showing that construction
workers accepted workplace risks that were ~ 4 times the risks factory
workers would accept and 16 times what office workers would accept.
Similar studies I reviewed at the time showed similar high variability
in individual risk tolerance. With an underlying population risk
tolerance distribution affected by such high individual variances, I
don't think one can draw conclusions from population data that are
useful for individual decision making.
> > You are applying population statistics to an individual, which is an
> > error in logic.
> It's not an error in logic. If we accept your premise, we would have
> to give up 90% of modern medicine!
It might not be a bad idea if we could give up about half of that.
> Nearly every therapeutic treatment
> in medicine has been studied and justified using population data.
Many have not, and many squeaked in with such low efficacy that the drug
companies, for example, should not have been allowed to claim their
products are effective.
> While some can be fine-tuned by more specific study, you'll _never_
> hear "Since you're between 6'1" and 6'2" tall, weigh between 200 and
> 205 pounds, are blonde and wear a beard, this vaccine should work for
> you. Good thing you don't have red hair!"
It is well known that people do not respond to drugs and treatments
uniformly. The more we know about the odds, the better -- or at least
that is what my doctor tells me.
> And you seem to ignore the fact that helmet proponents rely on worse
> data - data taken from demonstrably self-selected groups - which they
> then apply to everyone. Helmet promotions never say "If you are white,
> male, have good insurance coverage, ride mostly on bike paths, fall
> mostly on soft surfaces in incidents that don't involve cars, you
> should always wear a helmet." That is, however, a _slightly_ more
> accurate interpretation of the study that generated the famed "85%"
I have made none of the statements in your previous paragraph. Please
don't assume that because I debate with you that I take the same
position as everyone else who debates with you. That, too, is an error
> Instead, what do we hear? "Always wear a helmet." As if it applies to
Not from me.
> > > Let's rephrase the question: Should helmets be recommended for people
> > > embarking on 25 km walks?
> > That wasn't, and hasn't been, the point I was arguing.
> No, it's more like the point you were avoiding - which is that cycling
> is not significantly riskier than walking or motoring. Yet you support
> helmet use only for cycling.
No, I WEAR A HELMET WHEN CYCLING. It is a personal decision which I
base on my risk in my circumstances. Feel free to guide all your
personal decisions by gross population metrics if you wish. I'll use my
> > >
> > > At present, they're obviously not. Browse any backpacking literature
> > > to see. (And those deal with - horrors! - isolated areas with insecure
> > > footing!)
> > >
> > > Should helmets be recommended for people embarking on 25 km runs?
> > I don't know. What is the risk for people who are fit enough to run 25
> > km? Is it the same as the underlying risk for the entire population?
> Hmm. You're retreating into a defense from ignorance. "The available
> data shows one thing. But there's a slight possibility this subset is
> different, so we _must_ assume it _is_ different."
You're using population statistics slavishly, disregarding their utility
for individual decision making. Do you govern your entire life based on
population stats? For instance, do you drink the 1-2 glasses of wine
per day that the stats tell you are correlated with reductions in risk
of heart disease? If so, would you do it even if you didn't like wine?
I don't -- the data are not yet convincing. How about taking aspirin to
reduce the risk of stroke? Population studies show it does. Do you do
it? I don't -- there are individual risk factors that mitigate against
it. There are many more examples of questionable conclusions drawn from
population statistics. A key question in using population data to draw
conclusions about what specific individuals ought to do is the
underlying variance among individuals.
> > Surely there's enough data available about head injuries during
> > competitions like the Boston Marathon that you don't have to rely on the
> > population statistics to make your point?
> I doubt it. But we've produced data. Do you have some to prove your
> point? If so, let's see it.
Humour me. Do you think that head injury risk for participants in the
Boston Marathon is likely to be significantly different from population
data for head injuries to pedestrians? Would you use the gross
population stats to make a decision about whether or not participants in
organized marathons should wear helmets?
You've produced data that I doubt is useful for individual decision
making, just like a lot of other population data. When you assure me
that you use this data to make decisions about every facet of your life
-- not just bicycle helmet use -- I'll take your faith in the data more