How a Grass Stem Redefined 'Human': Jane Goodall's Tool-Use Discovery and the Idea of Chimpanzee Culture

A definition built to exclude animals

Before 1960, the scientific consensus treated toolmaking as a defining, exclusive marker of humanity — the working definition in anthropology at the time was essentially "man the toolmaker," and observations of animals using objects were dismissed as incidental or instinctive rather than genuine tool use. This wasn't a casual assumption; it was load-bearing in how the discipline drew the line between human and animal cognition.

Jane Goodall arrived at what is now Gombe Stream National Park in Tanzania in 1960, sent by the paleoanthropologist Louis Leakey specifically because she had no formal scientific training and, in his view, would observe chimpanzee behaviour without the theoretical preconceptions that trained researchers of the era carried. She had no university degree at the time and worked initially without funding for equipment beyond binoculars and a notebook.

The observation at the termite mound

Within her first months at Gombe, Goodall observed a chimpanzee she had named David Greybeard strip the leaves from a grass stem, insert it into a termite mound, wait, then withdraw it covered in termites clinging to the stem, and eat them off. He repeated this deliberately and repeatedly — selecting a suitable stem, modifying it by stripping the leaves, and using the modified object as a tool for a specific purpose. She also observed chimpanzees at Gombe using crumpled leaves as sponges to soak up water from tree hollows they couldn't otherwise reach, another case of selecting and modifying a natural object for a functional purpose.

When Goodall reported the termite-fishing observation, Leakey's response became one of the most quoted lines in the history of primatology: "Now we must redefine tool, redefine man, or accept chimpanzees as humans." The field did the first of those three — the definition of tool use was revised to accommodate what she had documented, rather than dismissing the observation to preserve the old definition.

From one observation to a documented behavioural repertoire

A single anecdote would not have been persuasive on its own, and Goodall's approach from the outset was not to report an isolated sighting but to establish continuous, individual-based observation that could track how consistently and how widely a behaviour actually occurred. Over subsequent years, termite fishing was documented as a stable, repeated behaviour across the Gombe community, passed from mothers to offspring through direct observation and practice — young chimpanzees were seen watching adults fish for termites and gradually improving their own technique over months, not appearing with the skill fully formed.

Later research at other chimpanzee field sites across Africa — Taï Forest in Ivory Coast, Bossou in Guinea, Mahale in Tanzania — added further tool behaviours absent at Gombe: nut-cracking using stone or wood hammers and anvils at Taï and Bossou, and different termite-fishing tool designs at different sites even where termite fishing itself occurred at multiple locations.

Why cross-site variation is the actual scientific argument for culture

The strongest evidence for describing these behaviours as "culture" rather than simple instinct is not that chimpanzees use tools at all, but that different chimpanzee communities use different tools and techniques for the same underlying problem, in ways not explained by differences in habitat or available raw materials alone. Nut-cracking is present at some West African sites and absent at others with the same nut and stone species locally available; termite-fishing tool designs vary by community in ways that persist across generations at each site. That pattern — behavioural variation between populations that isn't fully explained by ecology, but that is stable within a population and transmitted through observation and practice — is the standard scientific definition of culture, and it's the reason a synthesis paper by Andrew Whiten and colleagues in 1999, drawing on decades of data including Goodall's Gombe records, was able to formally document dozens of behavioural variants across chimpanzee populations as a body of evidence for animal culture.

The methodological legacy

The scientific weight of the tool-use discovery rests on how it was documented, not just what was seen once. Goodall's insistence on identifying and following known individuals over years — rather than treating chimpanzees as an interchangeable, anonymous population — is what made it possible to show that termite-fishing was a learned, transmitted skill rather than a fixed instinct: watching a specific juvenile chimpanzee's fishing technique visibly improve over repeated observed sessions is qualitatively different evidence from a single observation of an adult doing it well. That individual-based, longitudinal method, developed out of necessity in 1960, became a template that shaped how field primatology has been conducted at long-term sites ever since.