Twenty years ago, Jared Diamond’s book “The Third Chimpanzee” highlighted a startling fact. If we adhere to the scientific rules for classifying species (taxonomy), humans should be classified as a third species of chimpanzee, or bonobos and chimpanzees should be classified as human.
Genetically, chimpanzees and bonobos are more closely related to humans than they are to gorillas (who are their next closest “relative”).
Our nearest relative
In evolutionary terms, chimpanzees are no more closely related to monkeys than we are. Twenty years ago, we discovered that human and chimpanzee blood haemoglobin have identical sequences of amino acids, and if blood chemistry is matched, humans can have a blood transfusion from chimpanzees.
At this time, most of the evidence for our close relationship to chimpanzees came from fossils and cognitive or behavioural studies. These found chimpanzees show affection and compassion, grieve for dead babies, hold grudges, use and make tools, develop lifelong friendships and display “Machiavellian intelligence” (political and social skills like deception and creating alliances). We knew that males hunt, engage in lethal primitive “gang” warfare with neighbouring communities and can physically abuse females.
Other studies of chimpanzees who can communicate with American Sign Language or other “languages” (for example, pictures, symbols, numbers) have shown some individuals have linguistic, mathematical and other problem-solving skills on par with some humans (even university students, in some cases).
More recently, studies of the chimpanzee “mind” suggest they can mentally “time travel”, like humans, by reliving past events and imagining or conceiving of what might happen in the future.
A moving video that demonstrates the ability to remember past events shows a well-known gorilla called Michael (also fluent in American Sign Language) describing the death of his mother by poachers when he was about three years old.
If our “sibling” species are capable of reliving traumatic events or anticipating future pain, this has serious ethical implications, since not only do they feel pain in the present, but their suffering is also increased by being able to experience pain and anxiety associated with past and future events.
On a more positive note, chimpanzees can also laugh just like humans, meaning they can experience pleasure. Just tickling a chimpanzee can result in raucous laughter. Sadly, few captive chimpanzees laugh, but wild infants often do.
The horror of lab testing
In 2005, preliminary results of the Chimpanzee Genome Project were published in Nature. The findings showed the genetic differences between humans and chimpanzees are so few (just a handful linked mostly to their sense of smell, immunity to disease and reproduction) that researchers were faced with having to ensure their findings were not used to increase pressure to use chimpanzees in biomedical experiments. Instead, they argued, we all have a moral duty to protect chimpanzees in the wild and in captivity.
According to legendary primatologist Jane Goodall and Dale Peterson in their book “Visions of Caliban: On Chimpanzees and People”, around 3000 chimpanzees housed in more than two dozen laboratories were being used to study human diseases and problems in 1993.
This was more chimpanzees than most African countries have left in the wild. Of these, about 1800 were in US laboratories as “animal models” for testing new vaccines for diseases such as AIDS.
On a tour of chimpanzee laboratory facilities in the US in 2001, I witnessed the conditions in which some chimpanzees were living. I wish I could erase those images from my memory.
The lucky ones were housed in social groups, with enrichment and access to large outdoor enclosures. The less lucky ones were housed in pairs, in small barred concrete-floored enclosures. The HIV-infected “death row” chimpanzees were housed in cages I was not allowed to see.
A new kind of captivity
Chimpanzees are also held as pets in the United States and elsewhere, sometimes in appalling conditions, with no central registry to keep track of where chimpanzees are, or how they are being cared for (or abused).
A recent study by Kara K. Schroepfer and colleagues shows people’s misperceptions about chimpanzees being cute and funny are fuelled by “entertainment” chimps, because they appear in sitcoms, commercials and on greeting cards dressed-up in human clothes, doing silly things.
But these silly primates are far from happy. If a chimpanzee is “smiling” at the camera, showing its teeth, it is actually a grimace of fear. Chimpanzees may look similar to us, but they do not smile like we do.