BOSTON

LIKE MOST PEOPLE, Rabbi Avi Shafran feels there is an enormous chasm between the behavior of humans and apes (“A world going ape,” Commentary, July 30).

Obviously, apes do not write poetry or build rockets (though NASA did send a few into space). It is therefore understandable that the recent decision by Spanish parliament to support rights for apes has been ridiculed.

But to Shafran, this is part of a larger problem because it “dovetails diabolically with larger societal changes,” including seeing humans as “not different in any meaningful way from the rest of the animal world.” While he acknowledges our physical and genetic similarities to apes, he remains firm that our intelligence and ability to conceive of right and wrong “sets us apart qualitatively.”

Yet the claim to human exceptionalism has been eroding steadily ever since 1960, when Jane Goodall observed chimpanzees using sticks to “fish” for termites in Tanzania. Tool use was then dropped forever from the list of behaviors believed exclusively human. That list continues to evaporate, and many anthropologists now see human/ape differences as a matter of degree, not kind. Observations of wild and captive apes (gorillas, orangutans, chimpanzees and bonobos) show that they have much more in common with us than once thought. Below is an incomplete list of some of these.

Intelligence. A few chimpanzees in Japan have been trained to count to nine by touching Arabic numerals, in order, on a computer screen. They can even do this after seeing the numbers scrambled across the screen for a fraction of a second, after which the number are covered but remain in their original location — and they do this better than college students. My favorite example of ape intelligence is a female chimp in a German lab who figured out how to acquire a peanut from the bottom of a long test tube by spitting out her drinking water, causing it to float. What percent of humans would solve this problem?

Self-awareness. In the lab, apes can recognize themselves in a mirror, an ability limited to a few other species, including elephants and dolphins. When an ape’s forehead is marked with paint by researchers, they notice the mark on their mirror image and proceed to touch the mark on their own body.

Language. Clearly, apes cannot speak. But they can understand human speech, and some have learned sign language. A male bonobo (or “pygmy chimpanzee”) named Kanzi at the Great Ape Trust in Iowa stands out here. With near flawless accuracy, he can recognize over 500 spoken words by pointing to a photo or symbol. He also demonstrates comprehension of basic grammar by following oral commands like “pour the Coke in the water,” rather than “pour the water in the Coke.”

Culture. Anthropologists are reluctant to ascribe culture to other species, but wild chimpanzees throughout Africa show roughly 40 different local “behavioral traditions” that are not the product of human influence. At one site in Tanzania, chimpanzees clasp hands in an extended “high five” while grooming each other’s fur, but this is not true of neighboring groups. As these groups represent the same species, the behavioral difference is likely not instinctive, nor does it affect survival. Instead, like any human fad, hand-clasping was probably introduced by some innovative individual and then spread throughout the group and even passed to the next generation. Such shared, learned behaviors form the essence of culture.

Altruism. Apes have a capacity for violence, including wild chimpanzees that form coalitions to seek out and kill individuals in neighboring territories (“chimpicide”?). However, like us, they are complex and also engage in behaviors that benefit others, even at a cost to themselves.

For example, chimpanzees have been seen risking their lives to save companions from drowning and reconciling after fights by embracing. Individuals not involved in a fight go out of their way to console the loser of a conflict or physically pull the former combatants together to “make up” and groom each other.

Lastly, consider the 1996 case of Binti Jua, an adult female gorilla at a Chicago zoo who gently cradled an unconscious toddler who had accidentally fallen 20 feet into the exhibit. She also carried the boy to a door where zookeepers could retrieve him, demonstrating an obvious propensity for empathy — even across species lines. Primatologist Frans de Waal says such examples illustrate that apes have the “building blocks of morality.”

To proponents of human exceptionalism, the suggestion that our most cherished qualities exist in other species is objectionable. To Shafran, it is “equating Cheeta with Tarzan.” An alternative view is that humans are of course special, but we can find gradual continuities with other species. And why shouldn’t we? After all, Cheeta and Tarzan may not be equivalent, but they are cousins.

Patrick F. Clarkin is an assistant professor of anthropology at the University of Massachusetts at Boston.