Thanks Ani! :-)

Thanks so much Iuia! I hope you enjoy reading it :-)

Thank you Cedric!

Also, read our official press release @mpi-animalbehav.bsky.social, including a video summary of our study! www.ab.mpg.de/793308/news_...

For more details, check out our paper. A huge thank you to everyone who has collected data for this project at SUAQ, and to all collaborators! Also thank you to the SUAQ project for providing all images above. www.nature.com/articles/s41...

This suggests that early hominin cultures were more expansive than can be predicted from surviving artifacts alone, including key information used for daily decision making.

Whilst accumulating culturally-dependent expanses of knowledge is a key facet of humans' generative and open-ended cultures, our results suggest that this capacity is likely ancestral to (at least) great-ape species.

In extension, we evidence that the breadth of cultural knowledge possessed by orangutans is likely more expansive than any one individual could produce independently (thus, a 'culturally-dependent repertoire').

We show that cultural transmission is essential for orangs to learn basic subsistence information in the wild. The repertoire of cultural information possessed by apes is likely to be far more expansive than social customs and highly technical skills, including simple info about 'what to eat'.

Preventing peering significantly slowed diet development, and removing enhancement effects on top of peering led to a larger stepwise reduction in diet size. Social enhancement (as well as maternally directed exposure to different foods) influence the majority of diet learning in orangutans.

Even when orangutans were presented with over 148,000 opportunities to interact with different food items over long-term development, orangs only developed adult-like diets (at least 90% adult repertoire) by adulthood if they also engaged in social learning.

Every single parameter of our ABM was estimated from wild data. When simulated orangs could engage in forms of social learning seen in the wild, the timings of diet development matched those observed in wild individuals (validating that our ABM captured wild orangs' learning from real-world inputs).

Leveraging over a decade of behavioral data collected in the wild, we constructed an agent-based simulation (ABM) of orangutan diet development between birth and adulthood (~15 years), focusing on individual exploration + social influences on exploration, e.g. exposure, enhancement and peering.

To answer these questions, we investigated whether social learning has important, long-term effects on the rate and outcomes of diet development in wild Sumatran orangutans. Moreover, we circumvent these methodological difficulties through running biologically relevant experiments ‘in-sillico’.

However, answering this question just using observational data in the wild is almost impossible – it’s extremely difficult to estimate the total knowledge possessed by wild animals, and to attribute knowledge acquisition to specific social behaviours or instances of individual exploration.

This is a critical question to answer for understanding the evolution of humans’ expansive cultures, and for understanding the role of culture in other animals’ development, behavioural ecology, and evolution.

Whilst many animal species exhibit the capacity to socially learn, it is unclear whether animals’ social learning similarly leads to the development of knowledge repertoires which are broader than animals could construct individually.

Humans use social learning to accumulate repertoires of knowledge that are significantly broader than any one individual could produce through their own efforts (we term, culturally-dependent repertoires).