Today, nature takes revenge. The University of
Houston's College of Engineering presents this
series about the machines that make our
civilization run, and the people whose ingenuity
Edward Tenner's new book,
Why Things Bite Back, is subtitled
Technology and the Revenge of Unintended
Consequences. And that, in a nutshell, is
Tenner's message. When we apply our technologies to
the world around us, things do indeed bite back.
In other episodes (e.g., 81, 457) I
talk about the way a new safety device lulls us
into carelessness and increases accidents -- how
pesticides and germicides breed new and tougher
insects and diseases. Tenner's idea isn't new, but
he does a fine job of rearticulating and
re-emphasizing it. Tenner's Revenge Effect means
that, if we mess with the natural order of things,
things bite back.
He takes care not to be simplistic in his examples.
New technologies certainly do improve the quality
of our lives. Medical procedures have reduced the
time we spend in hospitals and hastened recoveries.
Yet the number of procedures and medications a
patient undergoes has risen astronomically.
Laparoscopic gall bladder removals, for example,
are much less invasive than old-fashioned surgery.
The result is, far more people are having their
gall bladders removed and insurance costs are
rising. Worse still, we now find surgeons making
more mistakes when they use a grainy fiber-optic
image on a TV screen to guide miniaturized
Medicine has been shot through with routine hi-tech
medications, catheterizations, injections, IVs ...
Errors in a tiny percentage of these procedures
cause widespread harm because so many are done.
We suffer so many revenge effects in medicine
because the human system is terribly complex and
still poorly understood. Two hospital procedures
combine to produce effects that wouldn't be
produced by either one alone. Three or more
procedures can lay impossible demands on any
doctor's knowledge of side effects.
The same thing carries over into engineering
systems as they become more complex. Complex
devices that interact with our human system always
produce revenge effects. Tenner talks about
computers -- the way they've made our work routines
less straightforward than handling paper. We lose
enormous time and money learning software that
never stands the test of time. Meanwhile, eye
strain, neck strain, and carpal tunnel syndrome all
So does this mean we should reject new medicine and
turn away from computers? Hardly! New technology is
bred in our bones. The day we quit pioneering, we
quit being human.
The answer is as subtle as the problem itself.
Nature demands a wearing-in process. We have to be
alert to early warnings and ready to back off.
Wanting too much is what causes us to ignore those
warnings and react too slowly. And every time we
fail to listen, nature will forcefully get our
I'm John Lienhard, at the University of Houston,
where we're interested in the way inventive minds