As the water tumbles and foams, the world’s most famous chimpanzees sway rhythmically in a state of high arousal. First hurling rocks into the spray, the apes then quiet themselves and sit calmly, gazing at the waterfall before them. Jane Goodall, who knows these apes from 55 years of observation at Gombe, Tanzania, interprets these compelling images of our closest living relatives in a spiritual framework. The chimpanzees’ behavior, she says, are “perhaps triggered by feelings of awe, wonder” for magnificent natural features or events. Chimpanzees are so similar to us, she asks, “Why wouldn’t they also have feelings of some kind of spirituality?”

That question—rooted in Goodall’s definition of spirituality as the experience of appreciating magnificent, unknowable powers at work in the world beyond ourselves—has taken on a new urgency. Last month, a team of 80 scientists led by Hjalmar S. Kuhl and Ammie K. Kalan from the Max Planck Institute for Evolutionary Anthropology in Leipzig published a paper in Scientific Reports raising the possibility that chimpanzees at four field sites in West Africa may perform a ritual when they repeatedly throw stones at trees in the forest. The apes take aim at the trees with stones they have accumulated (or cached). This behavior, with its striking patterns of re-use of the same stones and trees, has never been observed at Gombe or the other best-known chimpanzee study sites.

Perhaps stone-throwing, the researchers say, originated as a male display. Males who do it vocalize and appear quite aroused, though an adult female and a juvenile also were observed to throw the stones, so the behavior appears to have caught on more widely. Alternatively, might the stone caches amount to symbolic marking of trees they consider to be sacred, in a way analogous to the cairn-building carried out by people living in the region?

Or couldn’t the apes, I have wondered, simply enjoy the sensations associated with forceful or aimed throwing, just the way we may delight in skipping stones across a lake? The key thing to notice, in any case, is that the researchers never used the word “spirituality” in the Scientific Reports paper, noting only that the chimpanzees’ stone accumulations are “superficially similar” to the human examples at “sacred” trees.

Weeks later, in a post  from The Conversation reprinted online in Slate and Scientific American, Laura Kehoe, one of the 80 Scientific Reports paper co-authors, took an extra speculative step: “Maybe we found the first evidence of chimpanzees creating a kind of shrine that could indicate sacred trees.” Within days, the media soared into hyper-drive. Earth and Sky  asked “Mysterious chimp behavior evidence of sacred rituals?” New Scientist’s headline “What do chimp ‘temples’ tell us about the evolution of religion?” is less skeptical, though the article itself adopts a more cautious tone. Caution was not a feature of tabloid newspapers’ accounts: The Mirror and the Daily Mail both featured headlines asking if proof is now here that chimpanzees believe in God.

Biological anthropologist and long-time chimpanzee field researcher Craig Stanford of USC dismisses all this hoopla flat out. “Ritualized behavior is common in the animal world,” he told me, “and chimpanzees throw stones in many contexts. The idea that this is proto-religious and the trees are somehow sacred sites is simply silly.”

The chasm between apes’ repeated throwing of stones taken from a cache at a tree, and apes’ creating the sacred through repeated action, is immense, and for Stanford, not navigable by science. Apes, as I have noted in my book Evolving God, do engage in certain acts of the imagination, including pulling an imaginary toy on an imaginary string (in captivity), and caring for a log apparently envisioned as a companion (in the wild). I’ve used instances like this, in addition to evidence for things like ape empathy and rule-following, to argue that the very deepest roots of human religiosity can be found in our primate cousins. But that’s a far cry from anointing them with a spiritual sensibility.

Feeling awe and wonder at nature is one thing—I’m really not about to disagree with Jane Goodall on this particular point—but linking those feelings necessarily with spirituality is another. (When I have watched baboons in Kenya, bison in Yellowstone National Park, and assorted wild visitors in my Virginia backyard, I have felt wonder. I haven’t felt spiritual.)

I was ready to move on from this entire question when I came across a book published last year. In Religious Affects: Animality, Evolution, and Power, Donovan Schaefer of Oxford University argues against our “lingering sense that religion makes us human by severing our animality.” Donovan rejects the Euro-American tendency to equate religion with belief, text, and language. Religion is something we feel in and express with our whole bodies, Schaefer insists, and once we realize this, we are free to see religion in other animals in certain instances of their embodied and emotional practices.

For Schaefer, animals who may not imagine God or spirits may connect with “things of power in the world” in religious ways. “Animal religion,” he emphasizes in the book, “is more than just a turn of phrase. Animal religion means animals have religion.”

The “prelinguistic dance” of wild chimpanzees at a waterfall, then, is religion for Schaefer, who goes further than Goodall in interpreting the meaning of apes’ rhythmic bodily movements in certain natural contexts. When I contacted Schaefer, he underscored in an email message to me the embodied nature of all religious practice: “The really thick, powerful elements of religion seem to come about in a sensory relationship with the world (whether that’s the natural world or the cultural world of stories and communities) that evokes awe and reverence.”

As Frans de Waal explains in his most forthcoming book,  Are We Smart Enough to Know How Smart Animals Are? the history of primate behavior as a discipline conveys a firm message: We must keep an open mind about what our closest living relatives can and cannot do, because often they will surprise us.  In Schaefer’s work, the necessary questioning of human uniqueness with respect to complex communication, tool-using, competitive status-striving and compassionate empathy is expanded in a fresh way: to embrace religion.

Compared to us, other animals, Schaefer told me, “have different life-worlds, different fascinations, different interests emerging out of their complex evolutionary histories. That could be waterfalls, wildfires, storms, or features of the landscapes where they live, work, and play that somehow stick out for them. Their religions will be built out of their fascinations, just as our religions are built out of ours.”

Chimpanzees’ excited response to heavy rains and winds has been cited by Goodall as another window into animal spirituality. Schaefer, once again, goes further than Goodall: Bowerbirds who dance in stylized ways during courtship feature in his framework just as much as do our closest primate cousins. In both cases, it’s not just the motion itself that counts: It’s the act of creativity as these animals “draw from the matrix of thick material forces flowing through them.” Because bowerbirds collect and artfully arrange objects as part of courtship, Schaefer calls them “shrine makers.”

Given his broad view of religiosity, I asked Schaefer if he sees the West African chimpanzees’ stone-caching and –throwing behaviors as religious. He replied this way: “People will always debate what is and isn’t sacred, what counts and what doesn’t count as religious. But if we encountered a group of humans who returned to the same trees over and over and performed the same inexplicable action near them and didn’t seem to have any practical reason to do so, there would be lots of people who would interpret it through the prism of religion.”

Schaefer’s book is fascinating, mind-expanding, and entirely worth a read. It makes me want to keep thinking about a question I was ready to leave behind. For now though, I’m still a firm skeptic when it comes to invoking spirituality or religion in these close kin  of ours. I’m uneasy with making 1:1 comparisons between the meaning of human behaviors performed at trees in the forest and similar chimpanzee behaviors performed there. After all, even if we unbind religion from language, texts, and beliefs—as I think we should—isn’t it incredibly anthropocentric of us to expect other species to think and feel the way we do?