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HOW has the electronic office helped to trigger a worldwide escalation in
paper prices? Why do users of filtered, low tar and low nicotine cigarettes
inhale as much of these substances as smokers who stick to high-strength brands?
And why do pesticides help create hardier pests and antibiotics lead to tougher
microbes?

The immediate answers are no surprise. Word processors make it easier to
print multiple versions of a document. Smokers tend to block the air holes of
filter cigarettes and inhale more deeply to increase their nicotine intake. And
natural selection eventually outwits just about every weapon scientists can
develop against unwelcome organisms. Although diverse, these are all examples of
the same phenomenon—the revenge effect. Each breakthrough has eventually
created problems that tend to defeat the reason for adopting the technology in
the first place.

Take Melaleuca quinquenervia, for example, an Australian and
Malaysian tree that grows at an average rate of more than two metres per year.
Early this century, John Gifford, a Florida real estate developer and forester
at the University of Miami, believed the tree could survive in the southern part
of the state and produce a harvestable timber. In the 1930s, a colleague began
to plant the tree throughout the Everglades by spreading Melaleuca seeds from an
aircraft. Meanwhile, farmers planted the trees as windbreaks and fence rows, and
homeowners introduced them into their gardens.

The revenge effect struck later. No one could have foreseen that Melaleuca
would turn out to be a poor source of wood because its exceptionally thick bark
defeats conventional sawmill processing. And if this weren’t bad enough, the
tree has had devastating effects on the native sawgrass habitat.

Melaleuca thrives in areas like southern Florida because the frequent
fires cause it to release seeds. Native vegetation normally burns near the
ground and at relatively low temperatures. But when the Melaleuca catches fire,
the leaves in the crown often burn, raising the temperature to twice that of
native fires. Don Schmitz, a biologist with the State of Florida Department of
Environmental Protection, says that native hardwood trees can resist normal
ground fires but are helpless against the higher crown fires.

Melaleuca can also set off intense peat fires that irreversibly alter the
concentration of minerals and nutrients in the soil, causing changes in one
season that would otherwise take thousands of years.

Seldom has any plant so changed a landscape in such a short time. By the
1970s, it had spread to most of the water conservation areas of

the Everglades and began to pose a serious threat to the entire ecosystem.
Melaleuca now covers at least 2000 square kilometres and probably far more, says
Schmitz, and it is spreading at a rate of 200 000 square metres a day.

Neither is there any effective, safe herbicide against Melaleuca and even
manual destruction must be followed by return visits to uproot the thousands
of seedlings that can flourish after a tree is cut down.

As in nature, the consequences of apparent improvements in our working lives
can be surprising. The most notorious of today’s occupational injuries are
cumulative trauma disorders, also known as repetitive strain injury. As the
phrase implies, these conditions arise not from a single crushing or shearing
blow—something that technology is relatively good at preventing or
deflecting—but from thousands of small motions, each often normal and
innocuous in itself, yet disastrous in aggregate. For keyboard users, the major
risk appears to be carpal tunnel syndrome (CTS), a disease that has reached
epidemic levels in some newsrooms and offices. The result is a painful and
debilitating revenge effect caused by technology intended to make work more
efficient.

CTS is partly a consequence of human body design. A single narrow tube in the
wrist accommodates the nine flexor tendons that control the movement of the
fingers, and the long median nerve that runs from the spinal cord to the lower
arm and hand. Repeated flexing and extension of the wrist can expand the
fluid-filled protective sheaths that surround the tendons. These in turn put
pressure on the median nerve in the carpal tunnel, causing pain and discomfort.
The tendon sheaths thicken after repeated acute inflammation, resulting in
permanent and painful pressure in the carpal tunnel.

Less well known but even more striking is a revenge effect from the growing
number of computers that accept oral commands. According to the American trade
magazine Computerworld, reports of voice strain caused by
voice-controlled computers are growing steadily. The injury is caused by
shouting commands or from tension in the muscles that control the voice even
when speaking quietly. Speech pathologists are now teaching sufferers how to
speak, relax and breathe. In the late 20th century, staying relaxed may demand
ceaseless effort.

Even the world of sport has not escaped the revenge effect and there is no
better example than boxing. The introduction of the Queensberry rules in 1869
was designed to encourage greater skill among boxers and prevent the bloody
brawling of old-fashioned pugilism. Certain rules even appeared to protect
fighters, such as mandatory padded gloves and a count of 10 rather than 30 for a
knockout. But by yet another irony, the rules did the reverse, and rather than
spare the athletes, encouraged severe chronic injuries.

Brain damage

In reducing the risk of a broken hand, boxing gloves have had the revenge
effect of encouraging harder blows. The British Medical Association believes
that blows from a gloved hand are far more hazardous than the blows in a
bare-knuckle prizefight. Friction between the glove and skin can rotate the
head, creating violent accelerations and decelerations that damage and destroy
nerve cells. The BMA argues that repeated punches of this type, rather than
knockout blows, are the probable cause of Parkinson’s disease and other chronic
neurological ailments all too common among professional boxers. It even compares
today’s gloves to the caestus—the infamous weighted glove used by Roman
gladiators.

So how can we tackle revenge effects? The solution is to combine new
technology with vigilance and to develop the ability to recognise unfortunate
consequences early enough to counter them. The results of this approach are
already evident. It is why computers have back-up memories, why governments
enforce mandatory tests on everything from elevators to smoke alarms and why
X-ray screening is routine for critical aircraft parts. We will never avoid
biteback completely, as the example of voice overuse demonstrates. But with
flexibility, humour, and an eye on history, we may be able to minimise its
effects.