Chimpanzees

"Common chimpanzee, Pan troglodytes (West and Central Africa)"

"Bonobo, Pan paniscus (forests of the Democratic Republic of the Congo)."

"The human brain is composed almost exclusively of the [cerebral] cortex. The brain of a chimpanzee, for example, also has a cortex, but in far smaller proportions. The cortex allows us to think, to remember, to imagine. Essentially, we are human beings by virtue of our cortex."

"[S]ome of the most fundamental ideas that stood at the basis of the 1960s' influential theories have since been all but reversed by the scientific community. To begin with, field study—pioneered by Jane Goodall at Gombe, in Tanzania, from the mid-1960s, and joined by other researchers since—for the first time provided a close, sustained, and reliable scientific observation on the chimpanzees' way of life in their natural habitat. The findings have been revolutionary. For instance, it has been revealed that rather than being vegetarian, chimpanzees...crave meat as a prime food. Primarily, although not exclusively, males, acting in co-operation, isolate, hunt, and avidly eat other animals, mostly monkeys and small mammals, but also straying, weak or infant chimpanzees... [T]he chimpanzees' group—several dozen strong and consisting of males and females with their infants—has been found to be highly territorial. The males patrol the boundaries of the group's territory and fiercely attack any intruder, including foreign chimpanzees (but not lone females coming to join the group). They also aggressively raid foreign territories."

"Goodall documented a conflict between two groups that lasted several years. The males of one of the groups invaded and gradually, one by one, isolated and killed first the males and then the other members of the other group, finally annexing its territory. Instances of murderous aggression, even by females, especially against infants that were not their own, have also been observed within the group. Finally, on occasion, chimpanzees would threaten with, beat with and throw sticks and stones. From being humans' idyllic antithesis in the 1960s' culture, the friendly, playfully naughty, and intelligent, but also jealous, quarrelsome, killing, and even warring, chimpanzees now increasingly mirror what we have commonly thought about ourselves."

"I cannot conceive of chimpanzees developing emotions, one for the other, comparable in any way to the tenderness, the protectiveness, tolerance, and spiritual exhilaration that are the hallmarks of human love in its truest and deepest sense."

"Humans have more sympathy. In the chimp you have sympathy between a mother and a child but you seldom find it anywhere else. Sympathy is a very, very human characteristic."

"Studying chimps ‘has helped me to realize, perhaps more than anything else, just how different we are from them’."

"Children, behold the Chimpanzee, He sits on the ancestral tree From which we sprang in ages gone. I'm glad we sprang; had we held on, We might, for aught that I can say, Be horrid chimpanzees today."

"If chimpanzees can experience loneliness and mental anguish, it becomes more wrong to use them for experiments in which they are isolated and anticipate daily pain."

"The Cerebral Cortex is the surface region of the brain that is most strongly linked to intelligence. A human’s cerebral cortex, if flattened, would cover four pages of typing paper; a chimpanzee’s would cover only one page; and a rat’s would cover a postage stamp."

"That chimpanzees and humans kill members of neighbouring groups of their own species is...a startling exception to the normal rule for animals. Add our close genetic relationship to these apes and we face the possibility that intergroup aggression in our two species has a common origin. This idea of a common origin is made more haunting by the clues that suggest modern chimpanzees are...surprisingly excellent models of our direct ancestors. It suggests that chimpanzee-like violence preceded and paved the way for human war, making modern humans the dazed survivors of a continuous, 5-million-year habit of lethal aggression."

"Like Yanomamö villages, chimpanzee communities are kinship groups based on aggregates of closely related males and unrelated females who have emigrated from other kinship groups... Like Yanomamö war, chimpanzee lethal raiding takes place when a subgroup of males...deliberately invades the recognised territory of a neighbouring community... Do they suggest to us that chimpanzee violence is linked to human war? Clearly they do. The appetite for engagement, the excited assembly of a war party, the stealthy raid, the discovery of an enemy and the quick estimation of odds, the gang-kill, and the escape are the common elements that make intercommunity violence possible for both."

"Chimpanzees...live in societies that are xenophobic, wandering in small parties, fighting with neighbours... In chimpanzee society, patriarchy rules. Communities persist through a line of father-son relationships. Males are the inheritors of territory. Males conduct the raids and the killing. Males are dominant. Males gain the spoils... Territorial gains, like territorial losses, have different impacts on males and females. For a male-bonded chimpanzee community, conquered lands can include not only a larger foraging area, but also new females who may simply continue to forage in the same area of forest as before the boundaries changed, only now with a different set of defenders. So males of an expanding community can gain females, which means that male chimpanzees should want to expand their territory to the largest area they can defend."

"Just 6 million years ago, a single female ape had two daughters. One became the ancestor of all chimpanzees, the other is our own grandmother."