Evidence map›Paper›PMID 35075258›Full record

ArticleNature human behaviour2022

Field experiments find no evidence that chimpanzee nut cracking can be independently innovated.

Kathelijne Koops, Aly Gaspard Soumah, Kelly L van Leeuwen, Henry Didier Camara, Tetsuro Matsuzawa

Abstract read
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In one paragraph

Article in Nature human behaviour, 2022. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 15 papers.

0numbers the graph read from it
0cells of the map it votes in
15citing papers in PubMed
–field-weighted citation impact
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

15 citing papers in PubMed.

  1. Article
  2. Review
  3. Article
  4. Article
  5. Brokering peace in the ape (culture) wars.Evolutionary human sciences · 2026
    Article
  6. Article
  7. Article
  8. Cultural evolution, social ratcheting and the evolution of human division of labour.Philosophical transactions of the Royal Society of London. Series B, Biological sciences · 2025
    Article
  9. Article
  10. Article
  11. Review
  12. Review
  13. Article
  14. Article
  15. Article
4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

5 authors.

Kathelijne KoopsDepartment of Anthropology, University of Zurich, Zurich, Switzerland. kathelijne.koops@uzh.ch.
Aly Gaspard SoumahInstitut de Recherche Environnementale de Bossou, Bossou, Republic of Guinea.
Kelly L van LeeuwenAnimal Behaviour & Cognition (formerly Animal Ecology), Department of Biology, Utrecht University, Utrecht, the Netherlands.ORCID http://orcid.org/0000-0003-4068-3929
Henry Didier CamaraInstitut de Recherche Environnementale de Bossou, Bossou, Republic of Guinea.
Tetsuro MatsuzawaDepartment of Pedagogy, Chubu Gakuin University, Gifu, Japan.ORCID http://orcid.org/0000-0002-8147-2725

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

Cumulative culture has been claimed a hallmark of human evolution. Yet, the uniqueness of human culture is heavily debated. The zone of latent solutions hypothesis states that only humans have cultural forms that require form-copying social learning and are culture-dependent. Non-human ape cultural behaviours are considered 'latent solutions', which can be independently (re-)innovated. Others claim that chimpanzees, like humans, have cumulative culture. Here, we use field experiments at Seringbara (Nimba Mountains, Guinea) to test whether chimpanzee nut cracking can be individually (re-)innovated. We provided: (1) palm nuts and stones, (2) palm fruit bunch, (3) cracked palm nuts and (4) Coula nuts and stones. Chimpanzee parties visited (n = 35) and explored (n = 11) the experiments but no nut cracking occurred. In these experiments, chimpanzees did not individually (re-)innovate nut cracking under ecologically valid conditions. Our null results are consistent with the hypothesis that chimpanzee nut cracking is a product of social learning.

Indexed as

NutsPan troglodytesAnimalsFeeding BehaviorHumans

Identifiers

PMID35075258

What OpenQuestion holds

Textmetadata
Read underepoch 390

Registered trials

None linked

Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.