MANILA, Philippines - With up to six million years of evolutionary disparity, chimps have even been shown to be more capable with certain cognitive tasks than their human cousins. A study carried out in Kyoto, Japan, showed that chimps were capable of recalling number sequences displayed in squares in random locations on computer terminals for flashes of a second each. Trained to expect food as a reward for completing the tasks, the chimps were able to press each square in numerical order, a task human subjects failed to achieve.
It’s evidence of a so-called “cognitive reserve.” Primatologist Tetsuro Matsuzawa suggests this ability might have been lost in primitive humans, as we learned symbolization and language skills. “I call this trade-off theory,” he says. “If you want a capability like better immediate memory, you have to lose some other capability.”
They’ve certainly taken the first steps: Studies have long observed chimps fashioning spears from sticks and using them to hunt smaller primates for their meat, and stones discovered in the Ivory Coast date chimpanzee tool use as being at least 4,300 years old. The starch residues on the stones suggest that the chimps used them to crack open nuts and that this was a skill learned alone and not from mimicking humans.
In the Congo, in 2009, evidence was found of chimpanzees fashioning “tool kits,” which would fit a number of different purposes and allow them to hunt for food more efficiently. It was the first evidence of multiple tool use: The apes had certain tools for probing army ant nests and catching the ants as they crawled up the probe, and others for perforating nests so they could reach larger hauls of ants inside.
The research suggests that the chimps are choosing their tools based on the characteristics of the specific species they’re hunting. It’s even been suggested to be a “sustainable” way of harvesting their prey. Rather than destroying nests with their hands — resulting in any number of nasty bites from the more aggressive species and forcing the surviving ants to migrate to a new nest elsewhere — they’re able to tease out enough of the insects for a meal without destroying the nest, allowing them to return to feast again. Even more remarkably, chimps have been able to recycle these tools.
In the laboratory, certain species of ape have been taught to understand human language and use it to communicate. Using lexigrams on a computer display — symbols corresponding to various words — Bonobo Kanzi can respond to verbal requests, repeating a variety of different words spoken by Dr. Sue Savage-Rumbaugh. Kanzi can even understand novel sentences and is able to carry out tasks based on certain commands like, “Cut the onion with the knife.”
Dr. Savage-Rumbaugh believes we’re conditioned to see humans as being “special,” and that our abilities with fire and the use of tools and language provide clear evolutionary markers separating us from the animal kingdom. But her research suggests Bonobos and other apes may be capable of achieving many of these accomplishments. “As we look at culture, we come to understand who we are,” she says. “And I don’t think it’s in our biology. We’ve attributed it to our biology, but I don’t really think it’s there.”
Scientists now believe there’s just a 1.23 percent difference in the genes that separate Homo sapiens from chimpanzees and Bonobos. As well as making use of tools, chimps have been shown to be social creatures, capable of empathy, altruism, and cooperation in problem solving. They’re self-aware and can anticipate the impact of their actions on their environment.
It’s also certainly true that apes have been observed to understand the emotional toll of loss and that, as social animals, they are capable of consoling others and mourning for dead companions. A mother chimpanzee was observed carrying the corpse of her two-year-old daughter for days after she had died. And after fights between a pair of chimps within a group, others were observed consoling the loser, even acting as mediators to restore the peace.
In the wild, this aggression is often put to use for territory acquisition, and communities of chimpanzees are able to work together to attack their neighbors. Taking over neighboring territory results in increased land, improved security, extra resources, and better access to mates.
Indeed, this aggressive tendency formed the backdrop to Rick Jaffa’s screenplay for Rise of the Planet of the Apes starring James Franco, Freida Pinto, John Lithgow, and Tom Felton.
“I’d read a lot of stories about chimp attack,” Jaffa says. “Owners had raised chimps in their house for several years, and they’d just turn.”
Will Rodman (James Franco) is a scientist working within a large pharmaceutical corporation, Gen-Sys, conducting genetic research to develop a cure that restores damaged human brain tissue. He’s committed to finding a cure for Alzheimer’s, a disease that afflicts his father Charles (John Lithgow). When Will’s simian test subjects suddenly display bizarrely aggressive behavior, management deems the research a failure and Will must shut down his program.
Amid the confusion of the study’s sudden termination, Will finds himself charged with an overlooked newborn infant chimpanzee — a male, the newly orphaned offspring of his most promising test subject. That young chimp, destined for greatness, is named Caesar.
He secretly raises the young Caesar as his own, at home, while caring for his ailing father. “Will must now be a caretaker, not only to Charles, but to this baby chimp,” says Franco. “As the story progresses, Will becomes more of a person and less of a scientist, and starts to care about Caesar more than the success of the drug. Caesar is much more than a pet to Will; in fact, Will becomes a father figure to the very special chimp. Will becomes a father to his own father, as well as to Caesar.”
This isolated behavior forms the basis of our understanding about the notion of ape “culture,” that is: behavior acquired through social learning and not hard-wired or through trial and error. Neighboring chimp populations in Uganda, for example, have been found to use different tools to accomplish the same task, such as extracting honey trapped in a fallen log. Those in the Kibale Forest use sticks, while those in the Budongo Forest create absorbent sponges by chewing on leaves.
Sadly, disease, deforestation, and dwindling food sources mean ape societies are becoming increasingly smaller and more isolated, so that these cultural developments may not have a chance to prosper in the future. A pioneer in chimpanzee research, Jane Goodall first began shaping what we understand about apes in the 1960s. She recalls that when she first went to Africa, there were are least a million chimps in the wild and, “now there are perhaps only 150,000.”
Rise of the Planet of the Apes may revel in the notion of an aggressive species of apes dominating human life on earth, but it seems our own aggression and dominance might result in us losing these already highly intelligent animals for good.