Storytelling is a human universal. From gathering around the camp-fire telling tales of ancestors to watching the latest television box-set, humans are inveterate producers and consumers of stories. Despite its ubiquity, little attention has been given to understanding the function and evolution of storytelling. Here we explore the impact of storytelling on hunter-gatherer cooperative behaviour and the individual-level fitness benefits to being a skilled storyteller. Stories told by the Agta, a Filipino hunter-gatherer population, convey messages relevant to coordinating behaviour in a foraging ecology, such as cooperation, sex equality and egalitarianism. These themes are present in narratives from other foraging societies. We also show that the presence of good storytellers is associated with increased cooperation. In return, skilled storytellers are preferred social partners and have greater reproductive success, providing a pathway by which group-beneficial behaviours, such as storytelling, can evolve via individual-level selection. We conclude that one of the adaptive functions of storytelling among hunter gatherers may be to organise cooperation.

Humans regularly cooperate with non-kin, which has been theorized to require reciprocity between repeatedly interacting and trusting individuals. However, the role of repeated interactions has not previously been demonstrated in explaining real-world patterns of hunter–gatherer cooperation. Here we explore cooperation among the Agta, a population of Filipino hunter–gatherers, using data from both actual resource transfers and two experimental games across multiple camps. Patterns of cooperation vary greatly between camps and depend on socio-ecological context. Stable camps (with fewer changes in membership over time) were associated with greater reciprocal sharing, indicating that an increased likelihood of future interactions facilitates reciprocity. This is the first study reporting an association between reciprocal cooperation and hunter–gatherer band stability. Under conditions of low camp stability individuals still acquire resources from others, but do so via demand sharing (taking from others), rather than based on reciprocal considerations. Hunter–gatherer cooperation may either be characterized as reciprocity or demand sharing depending on socio-ecological conditions.

A friend in need is a friend indeed: Need-based sharing, rather than cooperative assortment, predicts experimental resource transfers among Agta hunter-gatherers. Evolution and Human Behavior, 40(1), 82-89.

A fundamental objective of modern zoos is promoting pro-environmental behaviors.This study experimentally assessed the contribution of zoo rangers (staff employed to engage visitors) in delivering a behavior change campaign promoting sustainable palm oil use. The campaign was delivered in a dedicated area in a walk-through animal exhibit, with rangers either "present" or "absent" in the campaign space.Questionnaires assessing awareness, knowledge, and purchasing intentions were completed by 1032 visitors. Two analyses were conducted: (1) comparing the impact of ranger presence versus absence (to assess the overall impact of having rangers present regardless of whether they talked to visitors) and ( 2) comparing the impact of talking to a ranger against demographically matched individuals visiting when rangers were absent (to assess the specific impact of talking to a ranger). Visitors who talked to rangers were more aware of palm oil, had more knowledge, and greater intentions of purchasing sustainable palm oil. However, as only one-quarter of visitors talked to a ranger, fewer differences were found comparing ranger presence versus absence. These findings suggest that rangers can be instrumental in communicating complex conservation issues and delivering zoo-based behavior change campaigns, but their impact is limited by low engagement rates.

Indigenous peoples' participation in the co-management of protected areas is recognised as essential for conserving both cultural and biological diversity. While this practice is increasingly common, few studies have quantitatively evaluated the efficacy of these initiatives. Here we examine levels of knowledge and involvement among the Agta, a hunter-gatherer population who co-manage the Northern Sierra Madre Natural Park, the largest protected area in the Philippines. We find that the Agta generally possess low levels of knowledge about the protected area they are supposed to co-manage. Participation in park management is hampered by several factors, including a lack of cultural sensitivity regarding the Agta's foraging lifestyle among park officials and little political will to realistically empower and support the Agta as co-managers. Recommendations to strengthen Agta participation-and indigenous peoples' participation in protected area management more widely-are made to help protect the world's remaining cultural and biological diversity.