My
most recent post was a science fiction story which took a jab at the
strange thought patterns of some of today's scientists. In the story,
invading extraterrestrials arrive near our planet, and start leaving
more and more dramatic evidence of their arrival. The scientists
advising the US president keep denying that anything paranormal is
going on, despite the evidence piling up to extremely high levels.
The US president is lulled into inaction by these assurances, and the
chance to defend against the attack is lost, resulting in the
conquest of planet Earth.
At
one point in the story, a scientist says this in response to massive
testimony about extraterrestrial activity:
You
can't trust anecdotal evidence like that. We don't trust the reports
of ordinary people. Our motto is: only believe it if it was reported
in a scientific journal.
Now,
upon reading that, you might complain that this is a crude caricature
of what scientists say. But two days after writing the story, I read
a scientist say almost exactly this. The scientist (Alex Bezerow)
makes this claim:
Testimonials
mean nothing. Period. Anybody
with a modicum of scientific training understands that.
The scientist then goes on to offer what he claims is an
“excellent example of how dangerous and misleading anecdotal
evidence can be” by citing a debunking of the famous Erin Brokovich
lawsuit, a debunking which is itself debunked in this article.
Bezerow's
claim that “testimonials don't matter” is a wholesale dismissal
of all anecdotal evidence. This is nonsensical. Anecdotal evidence
is simply evidence in which a person describes what he did, or what
happened to him. Such evidence is a key pillar of our legal system,
and (as I will show in a moment) is actually a key pillar of modern
science.
When
someone makes a ludicrous claim such as “testimonials mean nothing,” or claims that anecdotal evidence doesn't count, you have
to ask: what is their motive? What would motivate someone to advance
such a bizarre principle, so contrary to common sense?
I can
think of two motives that a scientist might have for advancing such a
principle. The first is that a dismissal of anecdotal evidence is
very convenient for someone who wishes to advance a narrow,
restrictive view of reality, particularly a view dominated by
mechanistic or materialist principles. If you want to maintain that
there is nothing but matter and energy, you have the problem that a
significant fraction of the population report psychic, paranormal, or
spiritual experiences that go beyond such a limited reality. It is
very convenient, therefore, to be able to “cross out” all such
reports by claiming that anecdotal reports aren't good evidence.
Another
motive that a scientist might have for advancing such a principle is
that he might be trying to shore up scientists' attempts to establish
a kind of knowledge monopoly, in which scientists are regarded as
some special priests of learning who are the sole possessors of the
keys to truth. Such attempts have grown more and more brazen in
recent decades. What better way to help enthrone our scientists as
the sole judges of truth than to tell the lowly masses that what they
observe and experience doesn't count, that only the work of scientists
counts towards establishing the truth?
But
such attempts are futile. One reason is that a large fraction of our
scientific papers are themselves anecdotal evidence.
Consider
a scientist who does experiments with rats or chemicals, and
publishes the results in a scientific journal. The account of the
experiment is itself anecdotal and testimonial. So if
we disregard anecdotal evidence, we must then disregard all of the
scientific papers in which individual scientists describe particular things they
did in an experiment. Bang, you've just wiped out a large fraction of
modern science.
It is
futile to rebut this objection by saying, “Such evidence isn't
anecdotal-- it's experimental.” A typical account of an experiment that a
scientist performed is both experimental and anecdotal, so you don't
show it's not anecdotal by showing it is experimental.
It's
also futile to rebut this objection by claiming that when a scientist
makes a claim in a scientific journal about his experiences, that
this has more weight than a non-anonymous account by an
ordinary person, on the grounds that the scientific journal is
peer-reviewed. When a scientific paper is peer reviewed, the
reviewers do not question the author, and do not ask to see
corroborating evidence. So the testimonial report of a scientist as to his experience while running an experiment has no more weight than the typical published account of a non-scientist who gives his correct name. A scientist doesn't sprinkle some magic truth dust on his anecdotal account by publishing it in a journal.
Of
course, scientists don't actually follow the principle that
“testimonials don't matter” or that “anecdotal evidence doesn't
count.” But a scientist may occasionally evoke such a principle
when he or she finds it convenient to dismiss some evidence that he
doesn't wish to accept.
We
can imagine how following the “ignore anecdotal evidence”
principle might lead to the unnecessary death of thousands. A
pharmaceutical company might introduce a new drug with baleful side
effects. Many people might report that their spouses died or had a
stroke after taking the drug. Such reports could be ignored as mere
“anecdotal evidence.” The death toll might mount, until tens of
thousands died. Finally, lagging far beyond the anecdotal evidence,
some scientific studies might show the drug was dangerous, and the
drug might be withdrawn by the pharmaceutical company.
This
scenario isn't imaginary. It's the actual history of a drug called
Vioxx, which is estimated to have killed 38,000 people.
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