Chimpanzees can plan and adapt their use of tools just like humans

In the early days of mankind, even the simplest tasks we now take for granted were hard-earned skills, sculpted over hundreds of thousands of years. From learning to make a fire to evolving complex language, these represent chapters in our evolution, much like the chimpanzee tool use that showcases early problem-solving abilities.

A recent study suggests that such fundamental abilities could have roots dating back even further, when our ancestors were still primates, swinging from trees rather than conversing over tea.

Complex human behaviors

Many human behaviors are highly complex, requiring intricate sequences, such as spoken language or tool-making.

These actions involve the ability to organize behaviors into chunks and understand relationships between different elements of a sequence, even if they are separated by other actions.

For instance, making a cup of tea or coffee involves multiple actions that must be done in the correct order – boiling water before pouring it, for example.

These tasks require breaking down complex steps into solvable parts, and humans are adept at switching between these chunks to adjust for unexpected occurrences, such as cleaning up spilled milk before continuing.

Until recently, it was unclear if non-human primates shared this flexible ability to organize behaviors.

Chimpanzees and tool use

The new research was led by the University of Oxford with an international team from the UK, US, Germany, Switzerland, and Japan.

The researchers explored whether chimpanzees, our closest relatives, display similar behavior when using tools.

The team studied wild chimpanzees in the Bossou forest, Guinea, analyzing tool use sequences captured in decades-long video footage.

These chimpanzees were documented using hammer and anvil stones to crack hard-shelled nuts – one of the most complex forms of natural tool use in the animal kingdom.

Observing chimpanzee tool use

The researchers recorded approximately 8,260 individual actions performed by the chimps as they cracked over 300 nuts, detailing each movement, such as grasping the nut, positioning it on the anvil, and striking with a hammer.

Using advanced statistical models, they discovered relationships between these actions that were similar to patterns seen in human behavior.

Specifically, half of the adult chimpanzees were shown to associate actions further along the sequence, suggesting they planned these actions rather than linking them reflexively, step by step.

Flexibility of chimpanzee tool use

“The ability to flexibly organize individual actions into tool use sequences has likely been key to humans’ global success,” noted Dr. Elliot Howard-Spink, the lead researcher.

“Our results suggest that the fundamental aspects of human sequential behaviours may have evolved prior to the last common ancestor of humans and chimpanzees, and then may have been further elaborated on during subsequent hominin evolution.”

Chimpanzees not only plan their tool use sequences but also adapt mid-process – such as adjusting tools or preparing multiple nuts before cracking them. This flexibility mirrors human-like problem-solving, where interruptions or adjustments are handled naturally.

Most chimpanzees in the study organized actions into repeatable chunks, just as humans do. However, not every individual followed this pattern, suggesting that these strategies might not be universal among chimpanzees as they are for humans.

Implications for human evolution

“There has been a renewed interest in the co-evolution of language and stone tool use in human evolution, and our study contributes to this debate,” said Professor Thibaud Gruber from the University of Geneva.

“While the connection between our results and early hominin stone tool use can be made more readily, how this connects with the evolution of other complex behaviours, like language, remains an exciting avenue of future research.”

Conservation and cultural preservation

Interestingly, the findings may also influence conservation efforts.

“There is increasing recognition that preserving cultural behaviors in wild animals – such as stone-tool use in West-African chimpanzees – should be incorporated into conservation efforts,” said Professor Dora Biro from the University of Rochester.

“Wild chimpanzees and their cultures are critically endangered, yet our work highlights how much we can yet learn from our closest relative about our own evolutionary history.”

Shared abilities across great apes

Since many great apes engage in complex, technical foraging, this capacity for intricate behavioral sequences might be present across other ape species as well.

More research is needed to determine whether these abilities are indeed shared among different great apes, and this is a priority for the team moving forward.

In addition, future research will focus on how chimpanzees group actions into higher-order chunks during tool use. Understanding the specific rules chimpanzees follow when organizing their behaviors will shed further light on how these skills emerge and develop over time.

The study offers fresh insights into the shared evolutionary roots of complex behaviors, including language and tool use.

By observing our closest relatives, we learn more about the fundamental skills that may have helped shape human success – long before the first words were spoken or the first tools were made.

The study is published in the journal PeerJ.

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