Chimps are natural born killers study shows
Our closest animal cousins used to be thought peaceful and only rarely aggressive. But new research shows that they are naturally bloodthirsty. What does this reveal about human nature?
Hunched low to the ground, the chimp troop creeps silently through the jungle, listening for any sound above the droning of insects. They close in on the enemy chimps, who lounge in low branches oblivious. Suddenly the attackers charge, overwhelming their terrified victims, kicking and biting them to death. Soon it is over, and the victors feast on the dead.
This brutal scene captured by a BBC film crew is typical of a chimpanzee attack. Until the 1970s, they were believed to be peaceful vegetarians, Then primatologists, observing them in the wild, realised that as well as sharing our talent for cooperation and relationships, they also seemed to share our capacity for violence.
Many argued that violent behaviour was not natural for chimps and that stress, brought by deforestation, poaching and other human activities, was causing them to act in uncharacteristic ways.
However new research just published conclusively refutes this idea. It examines all known cases of chimpanzees and bonobos killing their own species over the last five decades and finds that chimpanzees are naturally warlike - regardless of humans. For example, the Ngogo chimps of Uganda, ‘the most violent group of chimps there is’, are rarely disturbed by humans, and despite their pristine habitat, ‘they go around and kill their neighbours’.
The study suggests that far from being an anomaly, warfare may be a natural survival strategy for chimpanzees. When a rival troop is destroyed, the winners take over their territory and adds to their supply of food.
The research interests anthropologists because of what it might imply about human evolution. Chimpanzees are our closest relative sharing 98% of our DNA, and both species share a common evolutionary ancestor. If chimpanzees naturally cooperate in order to kill their own kind, does it imply that we humans have violence hardwired into our DNA as well?
Some researchers say that given that apes already share so many of our characteristics, it is no surprise that they are just as capable of warfare and murder. Human history shows that we are constantly drawn to wars of conquest and commit atrocities against our own species. The only thing that separates us from chimps in this regard is that we use technology to kill on a larger scale.
Yet others warn our shared genes tell us little — we share 65% of them with chickens, but chicken behaviour does not explain our own. In our desperation to understand our own nature, we project ourselves onto other creatures, but this makes us misunderstand other species. Blaming our warlike ways on nature is just a convenient way for us to avoid responsibility for our own failings.
- Does this new report on chimpanzees’ agression explain why humans so often go to war?
- ‘Too much of our time examining other species is spent actually looking for their similarity with us.’ Do you agree?
- In pairs, list as many qualities of humans as you can think of. Then go through the list and note which of those qualities you think are related to genes or evolution, and which are harder to explain.
- Use the links in ‘Become an expert’ to research how human’s capacity for warfare differs from that of chimpanzees. Make a table outlining the contrasts.
Some People Say...
“We are slaves to our genes.”
What do you think?
Q & A
- Why should I care about chimp warfare?
- As chimpanzees are so closely related to humans, we might be able to learn what is natural to us by looking at what is natural for them. Conversely, we might find that humans project their own concerns or values onto apes. Many scientists used to say human society is male-dominated because ape society is this way. However, few would use this as an excuse for chauvinism now.
- Are chimpanzees really as warlike as us?
- In some ways they are much more warlike. Research of early human society suggests that during mankind’s ‘hunter-gatherer’ stage, humans were 18 times less likely to kill for territory than apes. During this time, most human murders happened when males fought over a female. Controlling territory was not seen as essential.
- Primatology is the study of primates. Partly owing to the success of the ‘Trimates’, three outstanding female primatologists, the study is often celebrated as a ‘feminist science’. Yet this is based on an assumption that is in itself sexist; that males lack the empathy and patience to be good observers of primates.
- A species less well known than chimpanzees because it is only found in the Democratic Republic of Congo, bonobos are nevertheless very closely related to humans. Bonobos use sex as a form of greeting, a means of forming bonds, and as a way of making up.
- We also share 85% of our genes with a zebra fish, 60% with a banana, 36% with a fruit fly and 7% with bacteria. On average, all humans have a 99.9% biochemical similarity with each other. It is in the 0.1% that difference lies.