http://www.sciencebasedmedicine.org/?p=75   An extract---
A couple of years ago, I came across an article that explains this gulf
between how those of us trying to practice science- and evidence-based
medicine perceive the world and how most human beings not trained in
medicine or science perceive it. The article, which was published in 2006 in
the New York Times and written by Dr. Abigail Zuker, proposed one reason why
this might be, beginning with a discussion with her mother in which she
tries to convince her of the benefit of exercise, even in the elderly, a
concept that her mother would have none of and dismissed contemptuously:

 "Studies," she says, dripping scorn. "Don't give me studies. Look at Tee.
Look at all the exercise she did. She never stopped exercising. Look what
happened to her."

 End of discussion. Tee, her old friend and contemporary, took physical
fitness seriously, and wound up bedbound in a nursing home, felled by
osteoporosis and strokes, while my mother, who has not broken a sweat in the
last 60 years, still totters around on ever-thinning pins. So much for
exercise. So much for studies. So much for modern clinical medicine, based
on the randomized allocation of treatment and placebo. All that beautiful
science, stymied by the single, incontrovertible, inescapable image of Tee,
the one who exercised but grew hunched and crippled anyway.

My first thought would be that such a reaction represents the power of
anecdote over clinical data, but Dr. Zuker sees more than that. She sees it
as the difference between how doctors are trained to view the world and how
people untrained in medicine and science view the world, and she uses a
rather interesting metaphor to convey this difference:

 It is medicine's eternal quest, these days, to sell impressive science to
unimpressed patients, and it is hard to think of a group less equipped to do
it than doctors. Doctors are specifically trained not to think like normal
people, not to see what others see or to reason as others reason. They - er,
we - come to operate in an atmosphere so thin, so heady and attenuated with
the power of statistical analysis, that one might wonder whether we are
really on the same planet as the patients we try to convince of our truths.

 "Exercise helps the elderly." The doctor sees, from a perch suspended
somewhere up in the sky, a large football field filled with the elderly.
There are thousands of them down there, all dressed in sweats and sneakers,
dumbbells at their feet. Half of them are using the dumbbells, or are down
on their backs, doing leg lifts. The others just stand around.

 Over the years, of course, the ranks thin. The doctor watches, counts. It
begins to look as if there are more exercisers left. After decades, there
are definitely more exercisers. Of course, there are still a few sloths
standing around (and one of them looks suspiciously like my mother). But by
and large, the exercisers come to rule the field.

 That is the view from on high. Down on the field, of course, the view is
quite different. You are standing in a thick crowd, minding your own
business, living your life, but you cannot help noting that the man over
there threw his back out with all that exercise, and the woman next to you,
grunting to lift her dumbbell, had a heart attack. You cannot see to the
other end of the field and have no idea what is happening there. But
watching all the sweating and grunting and seeing some of those exercisers
disappear anyway, you decide to opt out.