Great ape cognition dataset brings studies together

The largest open record of great ape experiments assembled so far brings 18 years of scattered studies together in one resource on how apes think, learn and make choices.

It enables researchers to follow patterns in the same animals over time, helping them frame questions that individual studies could not address together.

The archive behind the great ape cognition dataset

At a research centre in Leipzig, Germany, archived experiments accumulated over many years recorded the choices of chimpanzees, bonobos, gorillas and orangutans.

By connecting those records, Dr Alejandro Sánchez-Amaro of the University of Stirling (UofS) documented a continuous body of evidence previously dispersed across individual papers.

The collection covers research conducted from 2004 to 2021, with the same animals appearing in numerous studies.

Even an archive of this size requires careful comparison, since no single task can reveal the full meaning of the evidence.

How scale changes conclusions

Research into ape cognition often depends on a small number of willing animals, meaning that the absence of one participant can alter the picture.

“Most studies therefore focus on specific questions and tend to produce relatively small datasets,” Sánchez-Amaro said.

The record includes 81 apes, 78 of which took part in more than one project.

Their repeated participation helps scientists distinguish a passing behaviour from consistent patterns in learning, memory or decision-making.

Making the files comparable

The EVApeCognition Dataset brings together 262 experimental datasets from 150 publications associated with studies at the Leipzig centre between 2004 and 2021.

Curators standardised the records so that corresponding details appeared in the same locations across the files.

Where the information was available to reviewers, the files retain each ape’s name, species, sex, role and age, as well as the test session and trial.

Following review and approval by the authors, the team recovered 61% of the eligible published studies for careful reuse.

Tracing the origins of intelligence

Research into great ape cognition – how apes think and solve problems – helps establish clearer links between observed behaviour and mental processes.

Chimpanzees and bonobos are humans’ closest living relatives, whereas gorillas and orangutans would need more observation because of more pronounced contrasts.

Comparisons across all four groups can show which skills have deep roots among apes and which developed differently in humans.

This distinction is important: shared abilities point to older inheritance, while differences indicate where human intelligence changed over the course of evolution.

Following minds over time

Long-term records allow researchers to observe developmental change – how abilities shift with age – in the same individuals.

“This resource will also allow researchers to track long-term patterns and explore developmental questions that are impossible to answer with single studies,” Sánchez-Amaro said.

Previous work found that some aspects of ape performance on tasks remained stable over time, suggesting that repeated tests can expose lasting individual differences.

On their own, these patterns cannot establish connections with humans, but they make comparisons sharper and claims about origins testable rather than vague.

Why open data matters

Older research can quietly be lost when files remain on private drives, in broken email accounts or on forgotten laboratory computers after staff leave.

One biology paper found that the odds of accessing data dropped by 17% each year after publication, illustrating why this archive is urgent.

The team followed FAIR principles, rules intended to make records findable and reusable, allowing other scientists to inspect the files.

A public repository keeps the material open access and free for others to use and check, preserving it beyond the lifespan of a single laboratory.

Limits of captive research

The new record nevertheless comes from captive apes at a single centre, rather than every ape population worldwide.

Because testing was voluntary, each task also reflects the animals that chose to participate, not a perfectly random sample.

Some older publications were left out of the dataset because questions concerning files, authorship or records could not be resolved.

These limits do not diminish the resource, but they help keep claims honest and guard against careless overinterpretation of the results.

From textbook claims to raw evidence

Teachers can draw on the same records to demonstrate how animal behaviour becomes scientific evidence.

Rather than simply memorising claims, students can compare ages, species, tasks and outcomes in genuine files from real studies.

The experience suits comparative psychology, the science of comparing behaviour across species, because it connects numbers with living animals.

Used thoughtfully, the dataset can encourage care as well as curiosity, particularly when students encounter complex and imperfect evidence.

Expanding the dataset

Later versions could include newer studies conducted after 2021 and, eventually, observations of everyday social life among the same apes.

With additional material, the Max Planck Institute for Evolutionary Anthropology could connect experiments with grooming, play, patience and cooperation in richer, more social ways.

Major collaborative projects have already demonstrated that primate research is strengthened when laboratories combine efforts across multiple sites.

For the Max Planck Institute for Evolutionary Anthropology, the larger challenge is to use access to develop careful questions, rather than merely make bold claims about intelligence.

A shared story of thinking across species

A once-scattered archive is now a shared tool for tracing how ape minds develop, differ and sometimes resemble our own.

Its greatest value will come from patient comparisons that acknowledge its limits while preserving rare animal histories for future researchers.