If war is hell, as Civil War General William Tecumseh
Sherman so famously observed, then why is it that human beings
continue to engage in such large-scale murderous pursuits that could
threaten the very survival of the species in our thermonuclear age?
Some leading scientists who have studied warfare through the ages
have long suggested that humans — the males of the species, at least —
have little choice when it comes to slaughtering one another in great
numbers. Such warlike behavior, the scholars contend, is hardwired
into the human brain.
We are, in other words, born to kill our own, an evolutionary trait
that sets us apart from nearly all other species on the planet.
Paul "Jim" Roscoe, a University of Maine professor of anthropology
and cooperating professor of Quaternary and climate studies,
subscribes instead to an equally long-held theory that suggests just
the opposite: humans actually have an innate aversion to killing.
However, Roscoe believes that this natural aversion can be disabled
when warfare is thought to be advantageous to a clan, a tribe or a
"It certainly raises big questions, though," Roscoe concedes of his
theory. "If we do have an aversion to killing, how is it that we
manage to kill pretty efficiently? And since we are a species that
kills, how could that aversion to it have evolved and persisted
Roscoe thinks he may have found the answer to this seeming paradox
in his exhaustive study of warfare among tribes in New Guinea, where
he lived for a year and a half in the early 1980s and has revisited
three times since.
"I argue that the uniquely developed intelligence of humans is the
faculty that resolves those questions," says Roscoe, whose article on
the subject will appear in an upcoming issue of American
Anthropologist, considered the country's preeminent journal in the
Recent Darwinian explanations for why some species kill their own
members, and why some don't, would lead us to expect that humans have
an aversion to killing, Roscoe says. "I suspect we do," he continues.
"But our highly developed intelligence actually finds effective ways
to 'disconnect' that disposition from our actions, thereby allowing
the innate aversion to persist.
"Given the great advances in warfare technology," he says, "it
becomes less and less smart to do what we do. It's really a terrible
dilemma that we're locked into."
Born in East Anglia, England, Roscoe began his professional
life as a physicist, a field that he quickly decided "did not sit with
me very well." He then spent three years trying to find a better fit,
including part-time work as a stringer for the BBC, following in the
footsteps of his father, a freelance journalist. When he later
discovered anthropology, however, he knew immediately it was the
career he'd been looking for.
"I felt that it could allow me to make a difference," says Roscoe,
who got his master's degree in anthropology at Manchester University
in England before heading to America to earn a doctorate at the
University of Rochester in 1983. He arrived at UMaine a year later.
In New Guinea, Roscoe first studied the need for family planning
and did ethnographic research among the Yangoru Boiken people living
in the foothills of a northern coastal mountain range.
In 1993, he began to steep himself in the study of the root causes
of war among the tribes of New Guinea, where myriad groups had been
fighting one another until well into the 20th century.
Roscoe believed that if he were to realize his hope of making a
difference to life on the planet, there was probably no better place
to start than by exploring the reasons humans wage war on one another
and are one of a small minority of species that kill to avenge the
death of kin.
For answers, he has spent the last 14 years rummaging in archives
around the world for information about New Guinea warfare, and
scouring the early accounts of German, Dutch and Australian
missionaries who once lived among the tribes of the South Pacific
Collating all that material, he admits with a grin, "was a little
like herding cats on LSD."
Roscoe has concluded that the highly developed human neocortex, the
part of the brain responsible for the creativity and intellectual
thought that enables us to achieve great things, also allows us to
envision when killing appears to be in our self-interest and then to
overcome our genetic predisposition against such behavior.
"This ability," he writes in his most recent article, "is
self-evident in the material technologies that allow humanity to
overcome so many of its physical limitations — for example, projectile
weapons and armory designed to circumvent the physical limitations of
bare hands and bared teeth for killing and the mortal jeopardy of soft
underbellies under fire."
The same weapons, he continues, also create the psychological
distance necessary for modern combatants to kill without having to
look one another in the eyes.
Our intelligence conveniently allows us to dehumanize our
enemies and perceive them instead as a lesser, undesirable,
threatening species that must be eradicated. In the Vietnam War, for
example, enemy soldiers were not human beings but "gooks." In the
Rwandan genocide, the Hutus called the Tutsis "cockroaches." In New
Guinea, enemies viewed each other as wild pigs and war as merely a
communal hunt for a porcine prey.
To the Soviets, Germany was a menacing tiger, Roscoe writes, while
Allied propagandists portrayed that nation as a "deranged, drooling
gorilla." The Nazis, on the other hand, sought to dehumanize their
enemies and the Jews by reducing them to "bacilli" or disease-carrying
"During military training in nation states and initiation in New
Guinea," Roscoe writes, "young men are secluded from society, stripped
of personal identifiers, subjected to verbal abuse and physical
ordeals that inflict anxiety, fear, pain, exhaustion, hunger and
dehydration, and then indoctrinated into the meaning and value of
masculinity and warriorhood."
All of which sounds a lot like what happens at modern military boot
camps, of course, and for good reason. If humans truly are born with
an innate aversion to killing, as Roscoe suggests, disconnecting it is
as critical to the making of a fearless young Marine today as it was
for the creation of a New Guinea warrior a century ago.
"The New Guinea village is the modern nation state writ small," he
says. "Or conversely, the modern nation state is the New Guinea
village writ large."
For many anthropologists, Roscoe says, the most vexing question
has been how humans, by their penchant for waging war and killing for
revenge, strayed so far off the evolutionary track.
"Most of the other species have a much more logical way of going
about it," he says. "They fight, but not in a very dangerous way."
Among other animal species, the outcomes of battle are usually
decided not by lethal combat but by ritualistic, threatening displays.
Red deer stags, to use a classic example, begin their territorial
confrontations in the wild by roaring at one another as a signal of
strength. Such bellowing bluster will often decide the matter, Roscoe
says, as one of the stags realizes it is clearly overmatched and
decides to throw in the towel. But if neither submits, the pair will
engage in "parallel walking," a side-by-side pacing display used to
intimidate and size one another up.
If that still doesn't do the trick, and neither stag backs off from
the showdown, the animals engage in fierce head butting that rarely
results in death.
"These ‘dumb' animals have actually worked out a sensible way to go
about it," Roscoe says, "and one that works to their mutual advantage.
They've devised a reliable way of figuring out who would win a fight
to the death without either of them having to fight one. The question
that anthropologists have wrestled with is why humans don't do the
About four years ago at the annual meeting of the American
Association for the Advancement of Science in Denver, Colo., the media
took notice when Roscoe first floated the theory that a highly
developed intelligence was the root of warfare and vengeful killing.
"I had briefly mentioned that we war because we're an intelligent
species, and that got quite a bit of attention," he recalls. "It was
kind of counterintuitive. We always speak of the great benefits of
intelligence, and now I was saying hold the phone, maybe intelligence
could be our downfall, given our thermonuclear technology. And the
revenge stuff caught their attention for all the wrong reasons.
Journalists were trying to get me to say George Bush attacked Iraq out
Roscoe expects his article in American Anthropologist to
generate similar interest, largely because his theory runs counter to
the argument by a leading anthropologist at Harvard, Richard Wrangham,
that human males are genetically predisposed to kill.
Roscoe admits that his opposing argument is speculative, and
extremely difficult to test in real-world situations. But if it were
to be proved sound one day, he says, it could offer valuable insight
about the nature of human warfare and why we insist on putting our own
species in peril.
"The more humans understand that they have this capacity," he says,
"the more cautious they might be about marching to war. The sheer
recognition that these are the kinds of creatures we are, and these
are the techniques we use to get ourselves to kill, might help us to
learn to behave differently."
Roscoe says it would be naïve to think that war could ever be
eradicated entirely, since there will always be Hitlers around to
"I suppose the most important thing is to try to limit the damage
that we do to ourselves," he says.
by Tom Weber
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